Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| the role of histamine in the anterior hypothalamus and its functional interaction with the hippocampus on exploratory behavior in adult male rats. | the possible effects of histamine (ha) locally applied into the preoptic area (poa) on hippocampus-mediated behaviors were studied in adult male rats. animals were double-implanted unilaterally with microinjection cannulae into poa and hippocampus (hpc). in experiment 1, ha was injected into poa and pyrilamine (h1-ha antagonist) or ranitidine (h2-ha antagonist) were microinjected into the ipsilateral hpc in two different doses. in experiment 2, ha was injected into poa and the histamine antagoni ... | 1992 | 1616603 |
| neuroanatomical specificity in the autoregulation of aromatase-immunoreactive neurons by androgens and estrogens: an immunocytochemical study. | testosterone (t) increases brain aromatase activity (aa) in quail and other avian and mammalian species. it was shown both in quail and in rat that this enzymatic induction results from a synergistic action of androgens and estrogens. these studies provide little information on possible anatomical or cellular specificity of the effect. using a polyclonal antiserum against human placental aromatase, we have previously identified aromatase-immunoreactive (aro-ir) neurons in the quail brain and dem ... | 1992 | 1638401 |
| effect of hypothalamic lesions that induce precocious puberty on the morphological and functional maturation of the luteinizing hormone-releasing hormone neuronal system. | recent evidence has implicated the transforming growth factor-alpha (tgf alpha)/epidermal growth factor receptor (egfr) system in the mechanism by which hypothalamic lesions accelerate female sexual development. since acquisition and maintenance of reproductive functions depend on the secretory activity of lhrh neurons, the present studies were undertaken to characterize some of the cellular and molecular events that underlie lesion-induced activation of the lhrh neuronal network. bilateral elec ... | 1992 | 1639024 |
| behavioral action of estrogen in the male dove brain: area differences in codistribution of aromatase activity and estrogen receptors are steroid-dependent. | brain aromatization of androgen to estrogen (e) and presence of estrogen-receptor (er) containing cells (erc) are required for the control of e-dependent neural events under-lying male sexual behavior. we examined whether (a) numbers of erc and steroid-inducible aromatase activity are codistributed and directly correlated in the same brain areas of individual sexually active male doves and whether, (b) distribution of erc is altered by a change in e formation in preoptic areas known to be involv ... | 1992 | 1641076 |
| poa semilatent virus, a hordeivirus having no internal polydisperse poly(a) in the 3' non-coding region of the rna genome. | rna from the hungarian isolate of poa semilatent virus (pslv) directed in vitro synthesis of 120k, 75k, 25k (coat protein) and 20k polypeptides. in vitro translation of pslv rna was blocked by the cap analogue, m7gpp, thus suggesting that the virus rna was capped. pslv rna could be aminoacylated with [14c]tyrosine in vitro. the sequence of 1.5 kb from the 3' end of the pslv rna gamma component revealed two open reading frames (orfs) separated by a uridine-rich intergenic region. the putative pro ... | 1992 | 1645144 |
| estrogen receptor-immunoreactive glia, endothelia, and ependyma in guinea pig preoptic area and median eminence: electron microscopy. | the presence of estrogen receptors (ers) in nonneural cells in brain, including glia, ependyma, and endothelia, has not previously been documented with electron microscopy. this study employed immunocytochemistry to investigate whether er immunoreactivity (er-ir) is present in glial, ependymal, or endothelial cells in the medial preoptic area (poa) and median eminence (me) in the brain of gonadally intact female guinea pigs. tissue sections through these regions were immunostained with monoclona ... | 1992 | 1727710 |
| cold- and ethanol-induced hypothermia reduces cellular levels of mrna-encoding thyrotropin-releasing hormone (trh) in neurons of the preoptic area. | thyrotropin-releasing hormone (trh)-containing neurons have been implicated in the central control of body temperature. trh-containing neurons are located in brain areas known to influence body temperature, and trh injected into these areas can produce changes in body temperature. while these lines of evidence support the view that central trh is involved in thermoregulation, it has been difficult to confirm that trh-containing neurons of the preoptic area are involved in this process. we used a ... | 1992 | 19912886 |
| immunocytochemical localization of 11 beta-hydroxysteroid dehydrogenase in hippocampus and other brain regions of the rat. | the dehydrogenase form of 11 β-hydroxysteroid dehydrogenase (11-dh) which catalyzes the oxidation of the biologically active steroid, corticosterone, to its inactive metabolite, 11-dehydrocorticosterone, is found in rat brain. the distribution and localization of 11-dh-like labeling in the rat brain was examined by immunocytochemistry. 11-dh-like immunostaining was found in all subfields of the hippocampus and in many other parts of the brain, including the preoptic area (poa), central nucleus o ... | 1992 | 21554583 |
| relationship between cultural factors and nematodes on merion kentucky bluegrass. | a 2-year study was conducted on merion kentucky bluegrass turf (poa pratensis) to identify potential relationships among seasonal population dynamics of nematodes, chemical applications, thatch, tillering, dollar spot caused by sclerotinia homoeocarpa, clipping weight, and other factors. numbers of tylenchorhynchus maximus determined during june were inversely related to the wet weight of grass from may. one or more monthly counts of paratylenchus hamatus, criconemella rusium, and t. maximus neg ... | 1992 | 19283225 |
| influence of irrigation and heterorhabditis bacteriophora on plant-parasitic nematodes in turf. | daily irrigated, 80% pan replacement, and nonirrigated field plots of kentucky bluegrass (poa pratensis l.) were inoculated with a mixture of steinernema carpocapsae (all strain) and heterorhabditis bacteriophora (hp-88 strain) in 1988. in 1989, daily irrigated and nonirrigated plots were inoculated with hp-88 alone. the turf and associated soil contained populations of tylenchorhynchus dubius, t. nudus, pratylenchus penetrans, paratylenchus projectus, and criconemella rustica. in irrigated plot ... | 1992 | 19283039 |
| intrinsic and extrinsic modulators direct pretranslational expression of preoptic regulatory factor 1 (porf-1) messenger rnas. | genes of the diffuse neuroendocrine system are often widely expressed. we are studying a newly discovered peptide gene, preoptic regulatory factor 1 (porf-1). in the rat, porf-1 has been shown to be a unique, single-copy gene. although its exact function remains unknown, porf-1 encodes a gonadotropin-releasing hormone (gnrh) related sequence and we have previously shown that this gene is transcribed in the rat in a tissue-specific manner in the preoptic area of the hypothalamus and in the testis ... | 1991 | 19912824 |
| a sex-related difference in the developmental expression of class ii beta-tubulin messenger rna in rat hypothalamus. | axonal elongation, neurite outgrowth, and synaptogenesis are key events of mammalian brain development. the neuronal cytoskeleton plays a fundamental role in these changes, which are influenced by gonadal steroids in brain regions bearing the appropriate receptors. microtubules, which constitute a major portion of the cytoskeleton, are composed of alpha- and beta-tubulin polypeptide heterodimers encoded by multigene families. of the five beta-tubulin isotypes described, the genes encoding class ... | 1991 | 19912791 |
| fever induced by macrophage inflammatory protein-1 (mip-1) in rats: hypothalamic sites of action. | the purpose of this study was to clarify the central site of action as well as functional characteristics of the febrile response of the cytokine, macrophage inflammatory protein-1 (mip-1). guide cannulae for microinjection were implanted stereotaxically in the rat just above the pyrogen and thermosensitive area of the anterior hypothalamic, preoptic area (ah/poa). following postoperative recovery, the body temperature of each rat (tbo) was monitored during an experiment by a colonic thermistor ... | 1991 | 1756389 |
| post-rolandic cortical projections of the superior temporal sulcus in the rhesus monkey. | the efferent connections of different cytoarchitectonic areas of the superior temporal sulcus (sts) in the rhesus monkey with parieto-temporo-occipital cortex were investigated using autoradiographic methods. four rostral-to-caudal subdivisions of cortex (area tpo) in the upper bank of the sts have distinct projection patterns. rostral sectors (areas tpo-1 and -2) project to the rostral superior temporal gyrus (areas ts1, ts2, and ts3), insula of the sylvian fissure, and parahippocampal gyrus (p ... | 1991 | 1761745 |
| hypothermia and feeding induced simultaneously in rats by perfusion of neuropeptide y in preoptic area. | changes in the body temperature (tbo) of the unrestrained rat as well as the hyperphagic-like ingestion of food were simultaneously determined during the sustained elevation of neuropeptide y1-36 (npy) within the anterior hypothalamic preoptic area (ah/poa). a single guide tube was implanted stereotaxically in each rat for repeated perfusions by means of push-pull cannulae of either the csf solvent vehicle or npy. following postoperative recovery, each site in the ah/poa was perfused for 6.0 min ... | 1991 | 1763096 |
| the participation of histaminergic receptors of the rostral hypothalamus on the tonic release of luteinizing hormone (lh) in adult spayed rats under estrogen and progesterone treatment. | the influence of histaminergic sites in the preoptic-anterior hypothalamic area (poa-aha) on the basal release of luteinizing hormone (lh) under a continuous regimen of estradiol, progesterone, or both was studied in ovariectomized rats. different groups of animals were subjected to the following experimental schedule: at day 1, rats received a s.c. silastic implant filled with oil, estradiol, progesterone, or estradiol plus progesterone. seven days later (day 7), animals were implanted into the ... | 1991 | 2018632 |
| anorexia and adipsia: dissociation from fever after mip-1 injection in ventromedial hypothalamus and preoptic area of rats. | certain cytokines such as tumor necrosis factor (tnf) and interleukin-1 (il-1) act centrally to affect eating behavior and thermoregulation and may be involved in the physiological mechanisms leading to anorexia, adipsia and loss in body weight. the newly discovered macrophage inflammatory protein-1 (mip-1) infused into the anterior hypothalamic, preoptic area (ah/poa) evokes an intense hyperthermia. the present experiments were designed to determine whether mip-1 affects the feeding mechanism i ... | 1991 | 1742616 |
| nucleotide sequence analysis of three cdnas coding for poa p ix isoallergens of kentucky bluegrass pollen. | grass pollen allergens are one of the major causes of type i allergic reactions (allergic rhinoconjunctivitis, allergic bronchial asthma, and hayfever) in temperate climates afflicting 15-20% of a genetically predisposed population. workers have found considerable physico- and immunochemical heterogeneity within the grass pollen allergens which has made them difficult to purify for both therapeutic uses and further biochemical study. we recently reported the construction of a cdna library in lam ... | 1991 | 1702432 |
| the genes encoding nerve growth factor and its receptor are expressed in the developing female rat hypothalamus. | nerve growth factor (ngf), its messenger rna (mrna) and its receptor protein and mrna are found in several brain regions. little attention has been given to the possibility that the hypothalamus, which controls the endocrine system, may produce ngf and/or express ngf receptors. this would indicate the existence in this brain area of neuronal populations which are either target for ngf-responsive cells or sensitive to ngf, respectively. blot hybridization of polyadenylated (poly(a)+) rna to a mou ... | 1991 | 1708076 |
| distribution of substance p, gnrh, met-enkephalin in the central nervous system of the pig. | the distribution of substance p (sp), gonadotropin releasing hormone (gnrh) and met-enkephalin in the brain and spinal cord of the domestic pig is described for the first time. the levels of sp, gnrh and met-enkephalin were measured by specific radioimmunoassays in various regions of the brain and spinal cord of the pig. substance p and met-enkephalin are widely distributed within the central nervous system of the pig. high levels of sp were found in the preoptic area (poa), suprachiasmatic area ... | 1991 | 1714337 |
| extracellular serotonin levels change with behavioral state but not with pyrogen-induced hyperthermia. | extracellular 5-ht in the anterior hypothalamus/preoptic area (ah/poa) and caudate nucleus of the freely moving cat was measured using in vivo brain microdialysis. administration of 8-oh-dpat, a 5-ht1a receptor agonist that decreases 5-ht neuronal activity, decreased extracellular 5-ht in both brain areas. extracellular 5-ht levels were also examined in relationship to the sleep-wake cycle, because previous data from our laboratory have indicated that behavioral state is the primary determinant ... | 1991 | 1715390 |
| gabaergic control of receptivity in the female rat. | gabaergic neurotransmission has been implicated in the control of the steroid-dependent behavior, lordosis. gaba has dual effects on lordosis: it facilitates lordosis through actions in the medial hypothalamus (mhyp) and it inhibits lordosis through actions in the preoptic area (poa). in the present study, gonadally intact and ovariectomized female rats were behaviorally tested with a sexually active male. brains were removed from sexually receptive female either 1 or 24 h after behavioral testi ... | 1991 | 1870664 |
| characterization and mapping of melatonin receptors in the brain of three mammalian species: rabbit, horse and sheep. a comparative in vitro binding study. | melatonin receptors were characterized in the brains of three mammals (rabbit, horse and sheep) by an in vitro binding technique, using 2-[125i]iodomelatonin as labelled ligand. although binding sites for melatonin have been described recently in several vertebrate species (including the sheep), the rabbit and the horse have not been the subject of investigation so far. apart from characterization, the present report describes receptor distribution in a number of brain regions, thus allowing for ... | 1991 | 1645852 |
| effects of gamma-aminobutyric acid receptor agonists and antagonist on lhrh-synthesizing neurons as detected by immunocytochemistry and in situ hybridization. | gamma-aminobutyric acid (gaba) is thought to play an important role in the regulation of luteinizing hormone-releasing hormone (lhrh) release but its role in the regulation of lhrh gene expression and lhrh synthesis is not known. we hypothesized that since gaba appears to have primarily inhibitory effects on lhrh cells (at the level of the cell body), gaba may act to decrease lhrh gene expression and peptide synthesis. this hypothesis was tested by examining the effect of gaba receptor activatio ... | 1991 | 1661682 |
| excitatory amino acid modulation of lordosis in the rat. | microinfusion of the excitatory amino acid agonist n-methyl-d-aspartate (nmda) into the mediobasal hypothalamus (mbh) significantly reduced lordosis in estrogen plus progesterone-treated female rats at 10 min post-infusion with recovery to pretest values by 30 min (p less than .05; wilcoxon). microinfusion of the specific nmda antagonist d,l2-amino-5-phosphonopentoic acid (ap-5) into the same sites was without effect on lordosis responding of fully receptive females. there was also a significant ... | 1991 | 1678153 |
| the pre- and postnatal influence of hormones and neurotransmitters on sexual differentiation of the mammalian hypothalamus. | a number of brain structures and a great number of brain functions have been shown to be sexually dimorphic. it has also been shown that development and differentiation of these structures and functions proceeds during a critical pre- and postnatal period of increased susceptibility, and is controlled by gonadal steroids and neurotransmitter substances. the brain of male and female mammals seems to be still undifferentiated before the period of increased susceptibility to gonadal steroids and ne ... | 1991 | 1684787 |
| influence of neurotransmitters on sexual differentiation of brain structure and function. | newborn rats received daily subcutaneous treatment with compounds which influence serotoninergic, cholinergic, alpha-adrenergic and beta-adrenergic activity. in adulthood luteinizing hormone (lh) secretion pattern, female sexual behavior, and the volume of the sexually dimorphic nucleus of the preoptic are (sdn-poa) were determined. postnatal administration of l-tryptophan increased the volume of the sdn-poa significantly when given alone or when given simultaneously with testosterone propionate ... | 1991 | 1685710 |
| norepinephrine neurons in mouse locus coeruleus express c-fos protein after n-methyl-d,l-aspartic acid (nmda) treatment: relation to lh release. | in mouse, rat, and monkey, n-methyl-d,l-aspartic acid (nmda) modulates gonadotropin releasing hormone (gnrh) release by an unknown mechanism. in previous studies we found that normal male mice consistently responded to nmda administration with increased levels of plasma lh, as did most normal female mice and female hypogonadal mice with fetal preoptic area implants (hpg/poa). to investigate the mechanism of nmda-induced gnrh release, immunocytochemistry of c-fos protein (fos) was used for detect ... | 1991 | 1686742 |
| ethanol induced electroencephalographic changes from certain central loci of canine brain. | effect of intracerebroventricular (i.c.v.) ethanol on pre-optic area (poa) and hippocampus (hpc) was investigated by recording chronological changes in their electroencephalographic (eeg) activity, through chronically implanted cannulae and bipolar electrodes, in five conscious male beagle dogs. recordings were made for two hours after microinjection and compared with cortical (co) tracings. the predominant pattern of eeg activity from subcortical loci was high voltage discharges though synchron ... | 1991 | 1917008 |
| differential effects of cytokines on thermosensitive neurons in guinea pig preoptic area slices. | this study was undertaken to determine whether the reported different courses of the febrile responses to the cytokines interleukin-1 beta (il-1), interferon-alpha 2 (ifn), and tumor necrosis factor-alpha (tnf) might have neuroelectrophysiological correlates. the reactions of individual thermosensitive neurons in the preoptic area (poa) were evaluated by recording their extracellular single-unit firing rates (fr) in slices of guinea pig poa perfused with artificial cerebrospinal fluid (acsf), hu ... | 1991 | 1719827 |
| endogenous opioid suppression of luteinizing hormone pulse frequency and amplitude in the ewe: hypothalamic sites of action. | evidence suggests that endogenous opioid peptides (eop) inhibit pulsatile luteinizing hormone (lh) secretion during both the luteal and follicular phases of the ovine estrous cycle. further data from sheep and other species indicate that the hypothalamus is the primary site of action for this eop inhibition. the purpose of the following experiments was to determine which areas of the hypothalamus are involved in the eop inhibition of pulsatile lh secretion. regularly cycling ewes (n = 10) were s ... | 1991 | 1784345 |
| a study of 8 year neonatal deaths (1982-1989) of toa payoh hospital. | a study of 233 neonatal deaths out of 30910 livebirths over an 8 year period in the toa payoh hospital is done. the hospital has since ceased providing obstetric and neonatal intensive services from april 1990 due to restructuring of hospital care. the neonatal mortality rates (nnmr) from 1982-1989 ranged from 6.52 to 9.55 and there was no significant fall in trend (p = 0.13). one hundred and thirteen (48.5%) neonates who died were below 1500gm (vlbw). various causes of neonatal deaths were exam ... | 1991 | 2042075 |
| gonadotropin-releasing hormone mrna in the rat: distribution and neuronal content over the estrous cycle and after castration of males. | the decapeptide gonadotropin-releasing hormone (gnrh) stimulates release of luteinizing hormone (lh) and follicle-stimulating hormone (fsh) from the anterior pituitary. in the present study we used a 51-base oligonucleotide probe and in situ hybridization to study the neuronal content of gnrh mrna at several time points in the estrous cycle and 7 days after castration of male rats. gnrh mrna containing cells were found in the medial septum (sept), the vertical and horizontal limbs of the diagona ... | 1991 | 1793175 |
| microimplants of estradiol in the sexually dimorphic area of the hypothalamus activate ultrasonic vocal behavior in male mongolian gerbils. | the hormonal control of ultrasonic vocal behavior in the male mongolian gerbil was examined by comparing the behavioral effects of androgen with those of estrogen administered to the preoptic-anterior hypothalamic area (poa-ah) in castrates. by measuring radioactivity released from solid "floating" poa-ah microimplants (mean diameter, 141 microns) of testosterone (3h-t, mean weight, 880 ng) in experiment 1, we found that the steroid had a concentration gradient which fell rapidly from the edge o ... | 1991 | 1813379 |
| intraperitoneal injections of prostaglandin e2 attenuate hyperthermia induced by restraint or interleukin-1 in rats. | 1. the purpose of this study was to investigate the effect of the intraperitoneal (i.p.), intravenous (i.v.) or intrapreoptic area (poa) injection of prostaglandin e2 (pge2) on the body temperature of restrained and unrestrained rats. the effect of i.p. pge2 on the body temperature of rats during fever induced by i.p. injection of interleukin-1 beta (il-1 beta) was also investigated. 2. prior to injection, restrained rats had body temperatures of approximately 1 degree c higher than unrestrained ... | 1991 | 1822555 |
| retinofugal projections to the hypothalamus, anterior thalamus and basal forebrain in hamsters. | in part a of the study, the retinal inputs to the hypothalamus, anterior thalamus and basal forebrain of syrian hamsters were studied using intraocular injections of horseradish peroxidase conjugated to cholera toxin (ct-hrp). in the hypothalamus, the heaviest retinal input was to the suprachiasmatic nucleus (scn), however, many labeled fibers coursed through the scn to reach more caudal, periventricular and lateral sites including the anterior and lateral hypothalamus, the paraventricular nucle ... | 1991 | 2049607 |
| an update on thermosensitive neurons in the brain: from cellular biology to thermal and non-thermal homeostatic functions. | ts neurons in the brain, particularly in the poa, play a central role in thermoregulation, based on the good correlations between the activity of ts neurons and the thermoregulatory responses. such relationships have been observed during (1) thermal (hypothalamic and peripheral) and (2) pharmacological (amines, neuropeptides, cytokines, and exogenous drugs) stimulations, (3) during modulation of neural inputs from extrapoa brain regions, and (4) during actual thermoregulatory responses. in vitro ... | 1991 | 1857014 |
| dissociation of hyperthermic and hyperglycemic effects of central prostaglandin f2 alpha. | we previously reported that intraventricular prostaglandins (pgs) produced hyperthermia and hyperglycemia in anesthetized rats. however, the relationship of them is little known. we examined the relationship between hyperthermia and hyperglycemia induced by intraventricular pgf2 alpha using curarized and adrenal demedullated rats. iv curare completely prevented the pgf2 alpha-induced hyperthermia, but enhanced the hyperglycemic effect of pgf2 alpha. adrenal demedullation completely prevented the ... | 1991 | 1862225 |
| effects of exogenous steroids on androgen receptors in fetal guinea pig brain. | we treated pregnant guinea pigs on day 50 of gestation with 10 mg testosterone propionate (tp), obtaining fetuses 2, 4, 8, or 18 h later as well as after 5 days of treatment. in a second group of pregnant guinea pigs, dihydrotestosterone propionate (dhtp), estradiol benzoate (e2b), progesterone (p), or cortisol was given 2 h before obtaining fetuses. although tp treatment elevated fetal serum t (p less than 0.05), brain cytosolic androgen receptor (arc) content was unchanged in fetuses of either ... | 1991 | 1873381 |
| comparative neuroanatomy of the sexually dimorphic hypothalamus in monogamous and polygamous voles. | in the present work we evaluated the degree of sexual dimorphism in two cell groups of the medial preoptic-anterior hypothalamus (mpoa-ah) in monogamous and polygamous voles. quantitative determinations were made of volume, cell number, and cell density for the anteroventral-periventricular nucleus (avpv) and the sexually dimorphic nucleus of the preoptic area (sdn-poa). polygamous montane voles (microtus montanus) had a greater degree of sexual dimorphism in both cell groups than did monogamous ... | 1991 | 2054639 |
| an aid to stop thumb sucking: the "bluegrass" appliance. | a nonpunitive fixed appliance utilizing a teflon (e.i. du pont de nemours and co., inc., wilmington, de) roller is described. the appliance is used in conjunction with a program of positive reinforcement in managing thumb sucking in children 7-13 years of age. it has been used successfully in 24 children, with no cases requiring reinsertion. | 1991 | 1881818 |
| area-specific hormonal regulation of brain aromatase. | in vitro experiments were conducted to compare the steroid regulation of aromatase in preoptic and posterior hypothalamic areas. kinetic analysis of aromatase activity in the preoptic area (poa) and posterior hypothalamus (ahp) of castrated and intact doves indicate that both areas have a similar, high substrate affinity (apparent km less than 15 nm), but castration decreases the vmax to a greater extent in poa than ahp. this differential effect was confirmed using a single substrate (10 nm) con ... | 1991 | 1889004 |
| involvement of catecholaminergic systems in the zona incerta in the steroidal control of gonadotrophin release and female sexual behaviour. | previous reports have shown that dopamine (da) in the zona incerta (zi) has a stimulatory effect on gonadotrophin release. we have now investigated the possibility that steroids exert their feedback effects on the release of luteinizing hormone (lh) via catecholamine systems in the zi. since the same steroid regimes also stimulate female sexual behaviour, the possibility that the zi is also involved in the control of sexual activity was investigated. lesions in the zi increased proceptive and re ... | 1991 | 1901630 |
| brain aromatization of testosterone in the male syrian hamster: effects of androgen and photoperiod. | estrogen formed by aromatization of testosterone (t) is involved in the activation of sexual behavior and control of the neuroendocrine system in the male syrian hamster. our study examined whether daylength influences formation of estrogen in the preoptic area (poa) and other neuroendocrine areas (anterior hypothalamus, aht, and medial amygdala, ma) which are targets for t in behaviorally active males. estrogen formation in individual brain samples was assayed in vitro using the stereospecific ... | 1991 | 1901634 |
| high perfusate po2 impairs thermosensitivity of hypothalamic thermosensitive neurons in slice preparations. | the thermosensitivity of neurons in the preoptic area (poa) of guinea pigs was examined in slice preparations during perfusion with artificial cerebrospinal fluid (acsf) gassed with 95% o2/5% co2 (95% o2-acsf) or 21% o2/5% co2/74% n2 (21% o2-acsf). perfusate po2, pco2, and ph of 95% o2-acsf measured in the incubation chamber were, respectively, 402.9 mmhg, 39.1 mmhg, and 7.38; those of 21% o2-acsf were 154.0 mmhg, 33.1 mmhg, and 7.41. all the thermosensitive neurons (n = 6) originally identified ... | 1991 | 1904788 |
| convergence from the preoptic area and arcuate nucleus to the median eminence in acupuncture and nonacupuncture point stimulation analgesia. | lesion of the preoptic area (poa) or medial arcuate nucleus (m-harn) abolished acupuncture analgesia (aa). potentials in the median eminence (me) evoked by stimulation of the acupuncture point (ap) were not affected by lesion of either the poa or m-harn alone, but were abolished by concurrent lesion of both. no analgesia was produced by stimulation of the poa. analgesia produced by stimulation of the m-harn was abolished by lesion of the poa, and the abolished analgesia was restored by concurren ... | 1991 | 1933397 |
| a comparison of treatment outcomes for black patients and white patients with metastatic breast cancer. the piedmont oncology association experience. | prior studies have shown that black patients with breast cancer have poorer survival times compared with white patients even when adjusted for stage. seventy-four black patients treated on six piedmont oncology association (poa) protocols were compared with 74 randomly selected white patients treated with the same protocols to determine if race had any independent effect on response, time to progression, or survival time. patients were evenly matched for pretreatment characteristics with the exc ... | 1991 | 2025850 |
| effects of ewe breed and management system on efficiency of lamb production: iii. meat characteristics. | effects of management system, ewe breed, sex, and legume grazing on cooking and sensory characteristics and shear force of lamb meat were estimated from data collected on animals produced in three management systems. system 1 lambs were born in late fall and fed to slaughter on a concentrate diet. system 2 lambs were born in january and february and grazed pure stands of alfalfa or ladino clover after weaning. system 3 lambs were born in march and april and remained with their dams on native blu ... | 1991 | 1938639 |
| transforming growth factor alpha contributes to the mechanism by which hypothalamic injury induces precocious puberty. | it has long been known that lesions of the hypothalamus lead to female sexual precocity. while an increased production of luteinizing hormone-releasing hormone (lhrh), the neurohormone that controls sexual development, appears to mediate the advancement of puberty induced by these lesions, little is known about the mechanism(s) by which hypothalamic injury activates lhrh secretion. since brain lesions result in accumulation of neurotrophic/mitogenic activities in the injured area, we tested the ... | 1991 | 1946396 |
| gene expression for estrogen and progesterone receptor mrnas in rat brain and possible relations to sexually dimorphic functions. | a clear neuroendocrine sex difference lies in the ability of the female rat to produce an ovulatory surge of luteinizing hormone. preoptic neurons, as they respond to estrogen and progesterone, have been proven to be involved in this mechanism, with an emphasis on the possible participation of neurons in the anteroventral periventricular nucleus and the suprachiasmatic portion of the preoptic area (poa). further, prominent morphological sex differences have been reported in the rat medial poa. t ... | 1991 | 1958549 |
| medroxyprogesterone acetate and the nuclear uptake of testosterone and its metabolites by brain, pituitary gland and genital tract in male cynomolgus monkeys. | the synthetic progestin, medroxyprogesterone acetate (mpa), is used to treat male sex offenders, and it is also suppresses sexual activity in male monkeys. to examine the possibility that mpa may act as an anti-androgen in the primate brain, 4 intact male cynomolgus monkeys were given mpa (40 mg i.m.) once a week for 16 weeks, while 4 control males received i.m. injections of vehicle. all males were then castrated and 3 days later were given 3 mci [3h]testosterone ([3h]t) i.v.; 1 h after injecti ... | 1991 | 1825470 |
| rat brain xenografts reverse hypogonadism in mice immunosuppressed with anti-cd4 monoclonal antibody. | this study examines the effect of immunosuppression with monoclonal antibodies (mab) against the murine cd4 (l3t4), a cell surface glycoprotein expressed primarily on helper t-lymphocytes, on the viability and function of rat neural xenografts placed in the third ventricle of hypogonadal (hpg) mice. the hpg mouse fails to synthesize hypothalamic gonadotrophin releasing hormone (gnrh) and consequently there is a drastic reduction in pituitary gonadotrophic hormone content and a failure of postnat ... | 1991 | 1832105 |
| the effect of neonatal exposure to diethylstilbestrol, genistein, and zearalenone on pituitary responsiveness and sexually dimorphic nucleus volume in the castrated adult rat. | the neonatal hormone environment determines the sexually differentiated pattern of brain growth. estrogens, derived from intracerebral aromatization of testosterone, promote male sexual central nervous system (cns) development. developing animals may also encounter estrogens from plant, fungal, and xenobiotic sources (environmental estrogens). the purpose of this study was to assess the effects of environmental estrogens on the physiology and morphology of the hypothalamus and pituitary. neonata ... | 1991 | 1836392 |
| expression of a higher plant psba gene in synechocystis 6803 yields a functional hybrid photosystem ii reaction center complex. | the psba gene codes for the d1 polypeptide of the photosystem ii reaction center complex and is found in all photosynthetic organisms that carry out oxygenic photosynthesis. here we describe the construction and characterization of a strain of the cyanobacterium synechocystis sp pcc 6803 in which the three endogenous psba genes are replaced by a single psba gene from the chloroplast genome of the higher plant poa annua. the resulting chimeric strain, kwpas, grows photoautotrophically with a doub ... | 1991 | 1840918 |
| possible action of intracerebroventricular thyrotropin on brobeck's hypothesis. | the effect of icv administered tsh on brobeck's thermostatic hypothesis was evaluated by recording chronological changes in electrical activity of precise loci (poa, vmn and co) coupled by rectal temperature changes in dogs. the study revealed 1. tsh action on thermoregulation is biphasic in nature. 2. this action of tsh is not an independent act but depends on the reaction of satiety centre. | 1991 | 1819554 |
| responses of pre-optic area to intracerebroventricular thyroxine and thyrotropin in dog brain. | electroencephalographic activity (eeg) of pre-optic area (poa) was recorded after intracerebroventricular (icv) microinjection of thyroxine (t4) and thyrotropin (tsh) in conscious male dogs. recordings were made for two hours following microinjections. biphasic responses with increased amplitude were observed in both the treatments, but chronologically the responses obtained with t4 & tsh were opposite to each other. | 1991 | 1812106 |
| sexual dimorphism of the human brain: myth and reality. | many neuroanatomical sex differences have been identified in both animals and humans, which may form the neural bases for sex-specific behavior and reproductive as well as non-reproductive functions. the present essay gives a brief review of the findings on sex differences in the human brain. our observations on the human hypothalamus revealed that the shape of the suprachiasmatic nucleus (scn)--a structure involved in the regulation of circadian rhythms and reproductive cycles--is elongated in ... | 1991 | 1778230 |
| regulation of hypothalamic gonadotropin-releasing hormone and neuropeptide y concentrations by progesterone and corticosteroids in immature rats: correlation with luteinizing hormone and follicle-stimulating hormone release. | in a previous study, we demonstrated that progesterone (p4) and the synthetic glucocorticoid triamcinolone acetonide (ta), but not cortisol, could induce lh and fsh release in estrogen-primed ovariectomized immature rats. therefore, the purpose of this study was to determine if the stimulatory effect of p4 and ta on lh and fsh release were associated with changes in gnrh or npy concentrations in the medial basal hypothalamus (mbh) or preoptic area (poa). ovariectomized immature rats primed with ... | 1991 | 1749457 |
| corticocortical inputs to the dorsal and ventral aspects of the premotor cortex of macaque monkeys. | recent cytoarchitectonic, histochemical and physiological studies have shown that the lateral part of area 6 (the premotor cortex) of macaque monkeys can be divided into at least two subregions, each of which is considered to play an important role in motor control. one lies in the dorsal aspect of the premotor cortex (pmd) medial to the spur of the arcuate sulcus, and the other in the ventral aspect of the premotor cortex (pmv) lateral to it. since there is little information on the corticocort ... | 1991 | 1721118 |
| allergenic and antigenic cross-reactivities of group ix grass pollen allergens. | the allergenic and antigenic cross-reactivities between a major recombinant poa pratensis (poa p) ix allergen, rkbg8.3, and its corresponding proteins of different grass pollens were examined. immunoblotting of the proteins of thirteen different grass pollens using anti-rkbg8.3 antibodies indicated that poa p ix-like proteins are present in ten other grass pollens, albeit in variable amounts and polymorphic forms. these proteins ranged in size from 20 to 88 kda in different grass pollens. the pe ... | 1991 | 1721609 |
| long-term pinealectomy alters hypothalamic serotonin metabolism in the rat. | in the present study, the effects of long-term pinealectomy on tryptophan, 5-hydroxytryptamine (5-ht or serotonin), 5-hydroxy-3-indoleacetic acid (5-hiaa), and tryptophan hydroxylase and monoamine oxidase activities were studied in preoptic area-anterior hypothalamus (poa-ah) and in the medial and posterior hypothalamus of the rat. after pinealectomy, 5-ht levels decreased significantly in medial hypothalamus but increased in the poa-ah. the levels of 5-hiaa decreased significantly in the poa-ah ... | 1991 | 1721935 |
| preoptic-brainstem connections and maternal behavior in rats. | this study presents evidence supporting the view that preoptic area (poa) projections through the ventral tegmental area (vta) to lower brainstem regions are important for maternal behavior in postpartum rats. experiment 1 demonstrated that bilateral coronal knife cuts posterior to the vta disrupted maternal behavior, and experiment 2 demonstrated a similar disruption when a unilateral knife cut that severed the lateral connections of the medial poa was paired with a contralateral knife cut post ... | 1991 | 1663755 |
| synthesis of chiral and achiral pyranenamine derivatives. potent agents with topical ocular antiallergic activity. | the ss, rr and meso stereoisomers of pyranenamine sk&f 84210 were synthesized stereospecifically starting from commercially available (r)-(-)- or (s)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanol. in addition, two achiral pyranenamines 19 and 26 were also synthesized. when evaluated by intravenous and topical routes in the rat passive ocular anaphylaxis (poa) assay, (ss)- and meso-2 as well as achiral compounds 19 and 26 were found to be more potent antiallergic agents than (rr)-2. | 1991 | 1671418 |
| hypothalamic sites of catecholamine inhibition of luteinizing hormone in the anestrous ewe. | norepinephrine (ne) and dopamine (da) actively inhibit the release of lh in anestrous ewes. this can be detected as an increase in lh pulse frequency following i.v. injection of ne and da antagonists. the objective of this study was to determine the sites of these inhibitory actions in the ovine hypothalamus by using local administrations of the ne antagonist, phenoxybenzamine (pbz), or the da antagonist, pimozide (pim), into specific hypothalamic areas. each neurotransmitter antagonist was admi ... | 1991 | 1673066 |
| effects of deoxycorticosterone treatment on beta-subunit mrna for (na + k)atpase in brain regions determined by in situ hybridization. | 1. we have used in situ hybridization techniques to determine the mrna for (na + k)atpase in 20 brain regions from control rats and rats treated with high doses of deoxycorticosterone (doc). 2. doc-treated rats developed a salt appetite following the second hormone administration on alternate days and were used after the fourth doc administration. 3. doc treatment did not change the number of silver grains/cell deposited in cells from ca1, ca2, ca3, and ca4 hippocampal subfields, dentate gyrus, ... | 1991 | 1651164 |
| the bovine preoptic area and median eminence: sites of opioid inhibition of luteinizing hormone-releasing hormone secretion. | autoradiography was used to quantify opioid receptors in the median eminence (me) and preoptic area (poa) of the brain of eight heifers, and in vitro perifusion of me and poa tissue from seven cows and heifers was used to examine the release of lhrh after administration of naloxone (nal). for quantitative receptor autoradiography, [3h]nal was used as the radioligand and nal or morphine as competitors. specific binding of [3h]nal in poa and me resulted in linear scatchard plots with similar equil ... | 1991 | 1657852 |
| neonatal testosterone masculinizes sexual behavior without affecting the morphology of the dorsal preoptic/anterior hypothalamic area of female ferrets. | we examined whether testosterone (t) administered to female ferrets neonatally--a treatment known to enhance masculine coital capacity--induces formation of the sexually dimorphic male nucleus in the dorsal preoptic/anterior hypothalamic area (mn-poa/ah), and/or sensitizes dorsal poa/ah neurons to the stimulatory effect of later androgen treatment on somal dimensions. in males, the mn-poa/ah was present in all subjects, and exposure to androgen following castration at postnatal day 56 (p56) incr ... | 1991 | 2070265 |
| estradiol binding in the sexually dimorphic nucleus of the preoptic/anterior hypothalamic area of adult male ferrets and in the equivalent region of females. | a large number of estradiol-concentrating cells were visualized by autoradiography in a subpopulation of large neurons located in and around the sexually dimorphic male nucleus of the preoptic/anterior hypothalamic area (mn-poa/ah) of castrated male ferrets and in a comparable dorsal portion of the poa/ah of ovariectomized females. considerably fewer estradiol-labelled cells were seen in the non-dimorphic ventral poa/ah nucleus of both sexes. estrogen binding in cells in or around the mn-poa/ah ... | 1991 | 2070266 |
| differential regulation of brain aromatase by androgen in adult and fetal ferrets. | the contribution of androgens to the regulation of aromatase activity (aa), measured by quantifying the in vitro formation of [3h]estrone from 19-[3h]hydroxyandrostenedione precursor, was studied in equivalent microdissected brain regions of adult and fetal ferrets. in adulthood, aa was similar in the bed nucleus of the stria terminalis, medial (m) and lateral (l) preoptic area (poa), medial (ma) and lateral amygdala (la), ventromedial hypothalamus (vmh), and parietal cortex of gonadectomized ma ... | 1991 | 1999145 |
| effects of ewe breed and management system on efficiency of lamb production: ii. lamb growth, survival and carcass characteristics. | lamb growth, survival and carcass characteristics were compared for progeny of either 1/2-suffolk, 1/2-rambouillet (western) ewes or 1/2-suffolk, 1/4-rambouillet, 1/4-finnsheep (1/4-finn) ewes produced over 3 yr in three different management systems. system 1 lambs were born in late fall and fed to slaughter on a concentrate diet. system 2 lambs were born in january and february and grazed pure stands of alfalfa or ladino clover after weaning. system 3 lambs were born in march and april and rema ... | 1991 | 2005017 |
| effects of n-methyl-d,l-aspartic acid on luteinizing hormone secretion in normal mice and in hypogonadal mice with fetal preoptic area implants. | many aspects of reproductive function are corrected in hypogonadal mice with preoptic area grafts (hpg/poa). gonadotropin release and gonadal development are dependent on the presence of gnrh cells within the grafts and gnrh innervation of the median eminence. this study examined the effect of a known modulator of gnrh secretion, n-methyl-d,l-aspartic acid (nma), in adult normal and hpg/poa male and female mice. all hpg/poa males had significant testicular development after graft surgery, and mo ... | 1991 | 2019260 |
| hypothalamic indomethacin fails to block fever induced in rats by central macrophage inflammatory protein-1 (mip-1). | this investigation examined the extent to which the activity of a prostaglandin (pg) in the anterior hypothalamic, preoptic area (ah/poa) of the rat plays a role in the intense fever induced by macrophage inflammatory protein-1 (mip-1) applied directly to this anatomical region. for the microinjection of both a pg synthesis inhibitor, indomethacin, and mip-1 into sites within the ah/poa, guide cannulae were implanted chronically just above this pyrogen-reactive region. postoperatively, the body ... | 1991 | 1946595 |
| characterization of the major allergen of cynodon dactylon (bermuda grass) pollen, cyn d i. | an allergen from cynodon dactylon (bermuda grass) pollen, cyn d i, has been purified by a combination of concanavalin a-sepharose affinity chromatography, and carboxymethyl-sepharose chromatography. the allergen constitutes the major allergenic component of the pollen extract as observed by immunoelectrophoretic techniques, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, an ige-inhibition experiment, and skin testing. in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, cyn d ... | 1991 | 1955635 |
| postnatal development of gonadotropin-releasing hormone and cyclophilin gene expression in the female and male rat brain. | the rat preoptic area-anterior hypothalamic continuum (poa-ah) contains about 400-800 neurons that express the decapeptide gnrh and the 56-amino-acid gnrh-associated peptide. originating from the olfactory placode, these neurons migrate and establish their final distribution and connections in the poa-ah several days before birth. the aim of the present study was to examine whether the biosynthesis of the mrna encoding the precursor (prognrh) common to gnrh and gnrh-associated peptide undergoes ... | 1991 | 2036956 |
| immunologic characterization of a recombinant kentucky bluegrass (poa pratensis) allergenic peptide. | a recombinant peptide of kentucky bluegrass (kbg) pollen was synthesized as a fusion protein (fp) in escherichia coli by recombinant dna procedures and was compared with its natural counterparts with respect to its allergenic properties. the fp was demonstrated to bind to the ige antibodies (abs) of greater than or equal to 95% of 55 individual sera examined. a positive correlation (r = 0.90) was observed between the levels of ige abs corresponding to the fp and the grass-pollen extract(s). with ... | 1991 | 2045614 |
| synergistic induction of aromatase activity in the rat brain by estradiol and 5 alpha-dihydrotestosterone. | estrogens are produced locally from androgen precursors by cells within the hypothalamus and preoptic area (poa). the activity of the aromatase enzyme complex responsible for this intracellular conversion is controlled by gonadal steroids. the purpose of this study was to determine: (1) whether estrogen acts together with androgen to regulate aromatase activity (aa) and (2) whether nuclear androgen receptor levels are increased after exposure to combined treatment with estradiol benzoate (eb) an ... | 1991 | 2046863 |
| [value and limitations of neoplasm markers in the diagnosis of pancreatic carcinoma]. | in the last decades several markers of pancreatic neoplasia have been proposed to obtain a diagnosis as earlier as possible. prerequisites of a good tumor marker are high sensitivity and specificity. among the various substances, serum determination of pancreatic enzymes has been found of no utility in early diagnosis of pancreatic cancer, due to its lack in sensitivity and specificity. similar results with ribonuclease and deoxyribonuclease. oncofetal antigens (cea and poa) have been initially ... | 1991 | 2047559 |
| bombesin produces hypothermia in rats pretreated with 2-deoxy-d-glucose. | previous research has shown that microinfusion of bombesin into the preoptic area (poa) decreases core body temperature in rats that are food-deprived or made hypoglycemic with insulin. the present study employed 2-deoxy-d-glucose, a competitive inhibitor of glycolysis, to further investigate the importance of a reduction in glucose utilization in the production of bombesin-induced hypothermia. rats (n = 7) were pretreated with 2-dg (0, 25, 50, 100, 200 mg/kg; ip) followed by bombesin (100 ng/1. ... | 1991 | 2049613 |
| identification and characterization of the poa p ix group of basic allergens of kentucky bluegrass pollen. | we reported previously the primary structure of three full-length cdna clones that encode a new group of ige-binding proteins of kentucky bluegrass (kbg) pollen, designated as poa p ix. in the present study we have further characterized the cloned poa p ix proteins, identified the corresponding proteins in kbg pollen extract, and determined their antigenic relationships with other known grass pollen allergens. a recombinant ige-binding polypeptide rkbg7.2 that represents the c-terminal fragment, ... | 1991 | 2051020 |
| age-related deficits in brain androgen binding and metabolism, testosterone, and sexual behavior of male rats. | brain androgen binding and metabolism, serum testosterone (t), and sexual behavior were measured in old and young male fischer 344 rats. after completion of sexual behavior tests, blood was collected for t assay and brains were removed for simultaneous measurements of cytosolic (arc) and nuclear (arn) androgen receptors and aromatase activity (aa) in the preoptic area (poa), hypothalamus (hyp) and amygdala (amg). in experiment 1, old and young intact males were examined. none of the old males ej ... | 1991 | 2052127 |
| ventromedial hypothalamus as a target for oestradiol action on proceptivity, receptivity and luteinizing hormone surge of the ewe. | most of the literature suggests that in sheep as in rodents nervous structures involved in female sexual behaviour are not necessarily identical to those involved in the lh surge. in rodents, oestradiol triggers female sexual behaviour by acting on a restricted area of the mediobasal hypothalamus whereas the concomitant induction of the preovulatory lh surge is at least partially under the control of more anterior structures. the central sites of oestradiol action, however, remained poorly defin ... | 1991 | 2070261 |
| prenatal ethanol and the prepubertal sexually dimorphic nucleus of the preoptic area. | the volume of the sexually dimorphic nucleus of the preoptic area of the hypothalamus (sdn-poa) was determined in 14-31-day-old male and female rats whose mothers received a liquid diet containing 5% w/v ethanol from day 8 of gestation to parturition. pair-fed dams received as a nutritional control an equal volume of an isocaloric liquid diet with maltose-dextrin in place of ethanol. normal controls had laboratory rat chow and water available ad lib. the sdn-poa volume of ethanol-exposed males w ... | 1991 | 2062918 |
| pulsatile luteinizing hormone secretion in normal female mice and in hypogonadal female mice with preoptic area implants. | pulsatile lh secretion is driven by gnrh, the hypothalamic hormone that is lacking in the hypogonadal mutant mouse. preoptic area grafts containing gnrh neurons correct many reproductive deficits in hypogonadal mice. in this study we evaluated the pattern of lh secretion in hypogonadal female mice with preoptic area grafts (hpg/poa) and in normal female mice. normal females were ovariectomized at 10 weeks of age, and hpg/poa mice were ovariectomized 4 months after graft surgery. three weeks late ... | 1991 | 1989874 |
| exposure of two upland plant species to acidic fogs. | a system is described for exposing large numbers of plants to acidic fogs. the system allows low volumes of treatment solutions to be provided at particle sizes chiefly in the 5-30 microm range (equivalent to fog/cloud droplets). plants of poa alpina l. and epilobium brunnescens were propagated from material collected in snowdonia, north wales and exposed to fog treatments at ph values of 2.5, 3.5, 4.5 and 5.6. there were 3 x 4 h exposures per week which provided a total of 6 mm deposition. supp ... | 1991 | 15092062 |
| purpose of admission and resource use during cancer hospitalizations. | this study examined the role of purpose of admission (poa) in hospitalizations for lung, colon, and breast cancers, using the 1985 20-percent medicare provider analysis and review file. six poa categories were created from discharge abstract data. average hospitalization charges, per diem charges, length of stay, and rates of death varied significantly by poa (p < .001). rural and small hospitals were more likely to admit patients for palliation, while urban and large hospitals admitted relative ... | 1991 | 10145730 |
| effect of dietary energy, body condition and calf removal on pituitary gonadotropins, gonadotropin-releasing hormone (gnrh) and hypothalamic opioids in beef cows. | beef cows (n = 64) were slaughtered to evaluate effects of dietary energy and calf removal (cr) on hypothalamic and adenohypophysial endocrine characteristics. from d 190 of gestation until parturition, cows received maintenance (me; n = 32) or low (le; n = 32) energy diets (me = 100%, le = 70% nrc recommendations). after parturition, half (n = 16) of each prepartum diet group received low (le; n = 32) or high (he = 130% nrc; n = 32) energy diets. at 30 d postpartum, cows were slaughtered 0 or 4 ... | 1990 | 2143972 |
| synergistic interaction between opioid receptor blockade and alpha-adrenergic stimulation on luteinizing hormone-releasing hormone (lhrh) secretion in vitro. | the effects of opioid receptor blockade, alpha-adrenergic receptor stimulation and concomitant opioid blockade and adrenergic stimulation on lhrh neurosecretion was examined in tissue culture using perifused preoptic area-mediobasal hypothalamic (poa-mbh) explants. blockade of opioid receptors using naloxone (nal) resulted in increased (p less than 0.05) lhrh secretion from poa-mbh explants obtained from intact postpubertal female rats. after washout of the nal-medium, basal release rate was res ... | 1990 | 2154715 |
| morphological changes in the hypothalamic neurons of female rats exposed to continuous illumination. | the morphological changes of neurons in the paraventricular nucleus (pvn), suprachiasmatic nucleus (scn), ventromedial nucleus (vmn), preoptic area (poa), supraoptic nucleus (son) and arcuate nucleus (arn) were studied in 16-18 month-old long-evans female rats which had been exposed to continuous illumination (ll) for 11 months. most neurons in those hypothalamic areas showed compact cytoplasm with abundant nissl substances and evenly distributed chromatin. these morphological features were not ... | 1990 | 2269027 |
| sexually dimorphic areas in the brain of whiptail lizards. | the whiptail lizard species cnemidophorus inornatus exhibits sexually dimorphic mating behaviors. we report that complementary sexual dimorphisms exist in two hypothalamic regions in male and female c. inornatus. the anterior hypothalamus-preoptic area (ah-poa), which is involved in male-typical mounting and intromission behaviors, is larger in males. the ventromedial hypothalamus (vmh), which controls female-typical receptivity, is larger in females. the all-female whiptail lizard cnemidophorus ... | 1990 | 2285854 |
| [alterations of the sympathetic activity, plasma catecholamine content and pulmonary surfactant in neurogenic pulmonary edema in rats]. | neurogenic pulmonary edema (npe) was induced by microinjection of kainic acid into bilateral preoptic area (poa) of the hypothalamus in rats. sympathetic discharge of the left adrenal branch was recorded, plasma catecholamine (ca) was assayed and the physical properties of pulmonary surfactant (ps) of the lung lavage were measured. the results showed that some physical properties of ps were changed in npe, i.e. maximal surface tension (gamma max) decreased, minimum surface tension (gamma min) in ... | 1990 | 2278007 |
| anatomical segregation of two cortical visual pathways in the macaque monkey. | a number of lines of evidence suggest that, in the macaque monkey, inferior parietal and inferotemporal cortices process different types of visual information. it has been suggested that visual information reaching these two subdivisions follows separate pathways from the striate cortex through the prestriate cortex. we examined directly this possibility by placing injections of the retrograde fluorescent tracers, fast blue and diamidino yellow, in inferior parietal and inferotemporal cortex and ... | 1990 | 2278934 |
| aromatase activity in adult guinea pig brain is androgen dependent. | androgen metabolism in target tissues constitutes an important step for understanding hormone action. the in situ aromatization of androgen represents one of these metabolic events. we characterized aromatase activity (aa) in a microsomal preparation of brain tissue from adult guinea pigs since earlier reports questioned its presence in neural tissues of this species. analyses revealed an apparent substrate affinity (approximately 17 nm) that was equivalent in adult males and females. however, a ... | 1990 | 2289019 |
| [the influences of morphine microinjected into preoptic area on electric activities of pain response neurons in parafascicular nucleus of thalamus in rat]. | we have observed the influences of opioid-like substances in preoptic area (poa) on the electric activities of pain response neurons in parafascicular nucleus of thalamus (pf). the results were as follows: 1. morphine 10 micrograms/microliters or 1 micrograms/microliters microinjected into poa could remarkably inhibit the pain discharges of most (20/26, 19/23 respectively) pain excitatory neurons (pen) in pf. the frequency of evoked discharges was decreased nd the duration was shortened. after i ... | 1990 | 2293371 |
| increased gabaergic transmission in medial hypothalamus facilitates lordosis but has the opposite effect in preoptic area. | the role of gamma-aminobutyric acid (gaba) in mediation of lordosis in the rat has been unclear. we report here that gaba plays a dual role in the mediation of lordosis and has differential effects in the medial hypothalamus (mh) and preoptic area/anterior hypothalamus continuum (poa-ah). bilateral infusion of the gabaa antagonist bicuculline into the mh of cannulated females primed with estradiol benzoate and progesterone (eb + p) resulted in a marked and transient inhibition of ongoing lordosi ... | 1990 | 2302578 |
| circulating estradiol and the activation of male and female copulatory behavior in japanese quail (coturnix japonica). | previous experiments using systemic and preoptic area (poa) hormone treatments have shown that aromatization of testosterone (t) to estrogen (e) is essential for activation of male-typical copulatory behavior in castrated male japanese quail (coturnix japonica). two experiments were conducted to determine whether circulating estrogen levels characteristic of normal intact males are high enough to activate male-typical or female-typical copulatory behavior. in experiment 1, blood samples were dra ... | 1990 | 2307345 |
| termination of the hormone-sensitive period for differentiation of the sexually dimorphic nucleus of the preoptic area in male and female rats. | the volume of the sexually dimorphic nucleus of the preoptic area (sdn-poa) in the rat brain is several-fold larger in males than in females. the volume of the sdn-poa can be influenced significantly by the hormone milieu during early postnatal life. the purpose of the present study was to identify when termination of the sensitive period occurs during which exogenous androgen administration influences sdn-poa volume in males gonadectomized on the first day of postnatal life (fales) or intact fe ... | 1990 | 2331785 |
| cloning, characterisation and expression of vitellogenin gene of oreochromis aureus (teleostei, cichlidae). | cdna synthesised from liver poly a+ rna of estradiol-stimulated male oreochromis aureus was ligated to ptz-19r and transformed into e. coli. tg-1 to yield 6 x 10(4) clones/ug dna, of which 6% was vitellogenin positive. restriction maps indicate 4 possible subgroups of vitellogenin cdna, with homology, observed by southern hybridisation, at a fragment flanked by pst 1 sites. when the amino acid sequence derived from the dna sequence of poa vg 62 was aligned with that of s. gairdneri, x. laevis, c ... | 1990 | 2353928 |
| facilitation of sexual receptivity in hamsters by simultaneous progesterone implants into the vmh and ventral mesencephalon. | intracranial implantation experiments have shown that the ventromedial hypothalamus (vmh) is the most sensitive site for the facilitation of female sexual behavior by progesterone in estrogen-primed rats. however, similar implantation techniques have been much less successful in hamsters. several lines of evidence indicate that both hypothalamic and midbrain structures are important for hamster lordosis. therefore we compared the effect of progesterone (p) implants administered simultaneously to ... | 1990 | 2365298 |
| cytosol and nuclear estrogen receptor binding in the preoptic area and hypothalamus of female rats during pregnancy and ovariectomized, nulliparous rats after steroid priming: correlation with maternal behavior. | in a previous study, high nuclear estrogen receptor concentrations in the preoptic area (poa) were found on day 16 of pregnancy to prime females to respond to a subsequent low dose of estradiol benzoate (eb) after hysterectomy-ovariectomy by exhibiting maternal behavior in 48 hr. receptor concentrations in the poa were found to be higher than those in the hypothalamus (hyp). the present study investigated when nuclear estrogen receptors increase during pregnancy in poa and when the difference in ... | 1990 | 2365302 |
| expression of neural 5 alpha-reductase messenger ribonucleic acid: comparison to 5 alpha-reductase activity during prenatal development in the rat. | the present study was designed to characterize the developmental pattern of 5 alpha-reductase messenger rna (mrna) levels and enzyme activity in intact medial basal hypothalamic (mbh) and preoptic area (poa) tissue fragments of rats during fetal development. 5 alpha-reductase activity was determined using [3h]testosterone as the substrate and quantifying, by tlc, the radiolabeled 5 alpha-reduced metabolites (dihydrotestosterone [dht] and 5 alpha-androstane-3 alpha,17 beta-diol). confirmation of ... | 1990 | 2387251 |