peptides for calling? an immunohistochemical study of the avian n. intercollicularis.we used two phylogenetically distant avian species (dark-eyed junco, hyemalis, passeriformes; domestic pigeon, columba livia, columbiformes) to determine the immunocytochemical distribution of opioid (leucine-enkephalin, dynorphin b) and non-opioid (adrenocorticotropic hormone) peptides in the n. intercollicularis (ico), a midbrain region which plays a central role in the control of vocalizations. we found that, in both species, the peptides under study are present as fibers and terminal-like st ...19921351774
spatial memory and adaptive specialization of the hippocampus.the hippocampus plays an important role in spatial memory and spatial cognition in birds and mammals. natural selection, sexual selection and artificial selection have resulted in an increase in the size of the hippocampus in a remarkably diverse group of animals that rely on spatial abilities to solve ecologically important problems. food-storing birds remember the locations of large numbers of scattered caches. polygynous male voles traverse large home ranges in search of mates. kangaroo rats ...19921384199
identification and characterization of columbid annexin icp37. insights into the evolution of annexin i phosphorylation sites.annexin i (anxi) contains phosphorylation sites in its "hinge region" that have been implicated in the regulation of cell growth and/or differentiation. a pigeon (columba livia) isoform of this protein, annexin icp35 (cp35), has a very similar amino acid sequence overall but an unrelated sequence that lacks phosphorylation sites in the hinge region. we now report the identification and characterization of annexin icp37 (cp37) from pigeon. genomic cloning and southern blot analysis demonstrated t ...19921388165
visual-discrimination deficits after lesions of the centrifugal visual system in pigeons (columba livia).the effects of bilateral lesions of the centrifugal visual system (cvs) on the visual-discrimination capacity were studied in pigeons. three different behavioral experiments, each testing different aspects of visual analysis, were performed. in the first two experiments, a grain-grit discrimination task and a visual-acuity determination, stimuli were presented in the frontal binocular visual field. a third experiment investigated the early detection of slow moving objects, introduced into the mo ...19921390382
argon laser photocoagulation of the pecten oculi of the domestic pigeon (columba livia) using a specially designed contact lens.a specially designed -62-d polymethylmethacrylate contact lens for biomicroscopy of the fundus oculi of the pigeon is presented. the study shows the usefulness of the lens in argon laser photocoagulation of the pecten, a noninvasive technique for ablating the organ. in addition, previous studies on operative destruction of the pecten are reviewed. to our knowledge, this is the first time the macroscopic appearance of a photocoagulated pecten is documented.19921407959
delta-alad activity variations in red blood cells in response to lead accumulation in rock doves (columba livia). 19921421846
in vivo studies on the effects of ovine corticotrophin-releasing hormone, arginine vasotocin, arginine vasopressin, and haloperidol on adrenocortical function in the racing pigeon (columba livia domestica).this study investigates the effects of in vivo administration of pituitary stimulants in racing pigeons (columba livia domestica). plasma corticosterone concentrations were measured following intravenous administration of ovine corticotrophin-releasing hormone (ocrh) (0.1, 1, 10, and 100 micrograms/kg), arginine vasopressin (avp) (0.01, 0.1, 1, and 10 micrograms/kg), arginine vasotocin (avt) (0.01, 0.1, 1, and 5 micrograms/kg), and haloperidol (0.05, 0.5, and 5 micrograms/kg). compared with mamm ...19921426965
visual discrimination performance after lesions of the ventral lateral geniculate nucleus in pigeons (columba livia).pigeons were trained to perform simultaneous pattern and color discrimination tasks. after their training was completed, bilateral electrolytic lesions were made in the ventral lateral geniculate nucleus (glv). following the surgery, they were retrained to their preoperative performance levels. lesions of glv caused no deficits in pattern discrimination performance. the birds which had been trained for discrimination of red vs. magenta showed a slight decline in their performance. this impaired ...19921466786
evaluation of antibiotics for racing pigeons (columba livia var. domestica) available in the netherlands.antibiotics and chemotherapeutics marketed for use in racing pigeons (columba livia var. domestica) were evaluated by comparing the dosages and indications given by the manufacturers with the data obtained by pharmacokinetic, bacteriological and efficacy studies. this comparison showed that only three of the recommended dosages and indications of the 60 formulations marketed in the netherlands are scientifically sound and in accordance with the literature. it is to be expected that the majority ...19921487835
evaluation of anthelmintics, antiprotozoal drugs and ectoparasiticides for racing pigeons (columba livia var. domestica) available in the netherlands.anthelmintics, antiprotozoal drugs and ectoparasiticides specially marketed for use in racing pigeons (columba livia var. domestica) were evaluated by comparing dosages and indications given by the producers with data obtained from efficacy studies or empirical data. of a total of 63 products, 59% were in accordance with the literature. fifty-nine percent of the dosages and indications of anthelmintics were in accordance with scientifically obtained data, while for trichomonacides, coccidiostats ...19921487838
in vitro nitroimidazole resistance of trichomonas gallinae and successful therapy with an increased dosage of ronidazole in racing pigeons (columba livia domestica).six out of eight different trichomonas gallinae strains isolated from racing pigeons proved to be resistant to the nitroimidazole drugs ronidazole, carnidazole and metronidazole. the minimal cytocidal concentration of ronidazole was determined in in vitro experiments. moreover, a therapeutic dose for ronidazole was determined for the control of trichomoniasis in pigeons from which the resistant t. gallinae strains were isolated. it was a 5-fold increase of the recommended ronidazole dosage which ...19921487839
effects of physiological cycles of infused melatonin on circadian rhythmicity in pigeons.the role of the hormone melatonin in the circadian system of pigeons (columba livia) was investigated. using an automatic infusion system, melatonin at physiological levels was delivered for 10 h each day to cannulated, pinealectomized (p-x) pigeons in constant darkness. these cyclic infusions of melatonin entrained feeding rhythms in p-x pigeons while vehicle infusions were ineffective entraining agents. when the retinae of p-x pigeons were removed (e-x), feeding rhythms were abolished in const ...19921507159
[infection by avian chlamydiosis in breeding pigeons in new caledonia].an epidemiological survey on avian chlamydiosis, carried out by serological probing in 8 pigeon breeders representative of new caledonian livestock, combined with bacteriological research on pigeon organs and droppings was set up in new caledonia in order to determine the prevalence rate of this infection and to adapt sanitary regulations concerning pigeon imports. all sera collected (230) were analysed by complement fixation test (cft). the organs were diluted in sucrose solution, then stored f ...19921510340
the visual forebrain and eating in pigeons (columba livia).the contribution of forebrain structures to the control of visually guided eating behaviors was studied using a technique for reversible 'visual decerebration'. the procedure is based upon the fact that structures in the thalamus and telencephalon receive their visual inputs primarily from the contralateral eye. when the eye contralateral to the ablated hemisphere is occluded, the remaining eye has unilateral access to these structures. when the eye ipsilateral to the ablated hemisphere is occlu ...19921511264
in vitro influence of hormones on transport of glucose and glycogen in liver and muscle of pinealectomised pigeons, columba livia substantiate the increased peripheral utilization of blood glucose by pineal in wild pigeons, an in vitro study on the ability of liver and muscle slices of intact and pinealectomised wild pigeons (c. livia) in terms of uptake and release of glucose, and deposition and depletion of glycogen, in presence of insulin, acetylcholine, glucagon and adrenaline has been undertaken. a total insensitivity of liver and muscle of pinealectomised birds for glycogen deposition and insensitivity of liver fo ...19921512029
evaluation of domestic pigeons as sentinels for detecting arbovirus activity in southern california.flocks of sentinel domestic pigeons (columbia livia) detected increases in st. louis encephalitis (sle) and western equine encephalomyelitis (wee) virus activity in southern california concurrently with flocks of sentinel chickens. however, occasional low-titered, transient seroconversions to both wee and sle viruses also occurred in pigeons during periods when virus activity was not detected by seroconversions in sentinel chickens, by virus isolation from culex mosquitoes, or by human disease. ...19921536386
comparison between lead levels in blood and bone tissue of rock doves (columba livia) treated with lead acetate or exposed to the environment of alcalá de henares. 19921568060
is visual lateralization in pigeons sex-dependent?adult homing pigeons (columba livia) of both sexes were trained binocularly on a successive pattern discrimination task. after reaching criterion they performed the task on alternate sessions under monocular left or right viewing conditions. regardless of their gender, all animals reached higher pecking scores when sight was restricted to the right eye. due probably to a ceiling effect, the discrimination-accuracy scores did not differ between left and right condition. thus, at least with respec ...19921571103
time discrimination in columba livia and homo sapiens.pigeons' ability to discriminate stimulus duration, focusing on stimuli less than 1 s in duration, was evaluated in 4 experiments. in experiment 1, the performances of pigeons and humans were compared with a staircase technique, and in experiment 2, the method of constant stimuli was used. both experiments produced similar results: the pigeon and human data were well described by the generalized form of weber's law (getty, 1975). experiment 3 demonstrated that the birds did not use perceived bri ...19921578202
jaw movement kinematics and jaw muscle (emg) activity during drinking in the pigeon (columba livia).movements of the maxilla and mandible were recorded during drinking in the head-fixed pigeon and correlated with electromyographic activity in representative jaw muscle groups. during drinking, each jaw exhibits opening and closing movements along both the dorso-ventral and rostro-caudal axes which may be linked with or independent of each other. all subjects showed small but systematic increases in cycle duration over the course of individual drinking bouts. cyclic jaw movements during drinking ...19921593499
glycine-like immunoreactive input to sympathetic preganglionic neurons.the organization of glycine-like immunoreactive (gly-lir) processes was investigated within the sympathetic preganglionic neuropils of male sprague-dawley rats and pigeons (columba livia). sympathetic preganglionic neurons were retrogradely labeled with horseradish peroxidase following injections into the superior cervical ganglion in rats or into the avian homologue of the mammalian stellate ganglion (paravertebral ganglion 14) in pigeons. glycine-like immunoreactivity was visualized using post ...19921611482
vasoactive intestinal peptide binding sites and fibers in the brain of the pigeon columba livia: an autoradiographic and immunohistochemical study.the distribution of vasoactive intestinal peptide (vip) binding sites in the pigeon brain was examined by in vitro autoradiography on slide-mounted sections. a fully characterized monoiodinated form of vip, which maintains the biological activity of the native peptide, was used throughout this study. the highest densities of binding sites were observed in the hyperstriatum dorsale, archistriatum, auditory field l of neostriatum, area corticoidea dorsolateralis and temporo-parieto-occipitalis, ar ...19911645376
[vestibular nystagmus as a result of the interactions between semicircular canals and the otolithic membrane subsystems of the vestibular system].untreated and treated (unilateral section of utricular and saccular branches of the vestibular nerve) pigeons columba livia were rotated in the dark in the horizontal plane, the head being in a different position relative to the axis of rotation. the range of angular acceleration was 7-19 deg/c2 and the peak value of centrifugal acceleration was 0.5 g. the neck and eye nystagmus was recorded. it was found that: 1) the result of canal-otolith interaction was not directly related to the pattern of ...19911663187
excitatory and inhibitory amino acid neurotransmitter binding sites in the cerebellar cortex of the pigeon (columba livia).we used receptor autoradiography to determine the distribution of excitatory and inhibitory amino acid neurotransmitter binding sites in the cerebellar cortex of the pigeon (columba livia). alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid, kainate and metabotropic binding sites had highest levels in the molecular layer. n-methyl-d-aspartate binding sites, assayed with both [3h]glutamate under selective conditions and with [3h]glycine binding to the associated strychnine-insensitive glyci ...19911685884
the distribution of neurotransmitters and neurotransmitter-related enzymes in the dorsomedial telencephalon of the pigeon (columba livia).immunoreactivity to four neurotransmitters/transmitter-related enzymes was found in the dorsomedial telencephalon (hippocampal region) of the pigeon. putative afferent fibers containing choline acetyltransferase-like, serotonin-like, and tyrosine hydroxylase-like immunoreactivity were seen in a fiber tract passing through the septo-hippocampal junction and along the medial wall of the hippocampal region. the most intensive labeling of neuropil and terminals of all four substances was found in th ...19911687688
an immunocytochemical analysis of the lateral geniculate complex in the pigeon (columba livia).the lateral geniculate complex (gl) of pigeons was investigated with respect to its immunohistochemical characteristics, retinal afferents, and the putative transmitters/modulators of its neurons. the distributions of serotonin-, choline acetyltransferase-, glutamic acid decarboxylase-, tyrosine hydroxylase-, neuropeptide y- (npy), substance p- (sp), neurotensin- (nt), cholecystokinin- (cck), and leucine-enkephalin- (l-enk) like immunoreactive perikarya and fibers were mapped. retinal projection ...19911687743
projections of the parabrachial nucleus in the pigeon (columba livia).the ascending and descending projections of the parabrachial nuclear complex in the pigeon have been charted with autoradiographic and histochemical (wga-hrp) techniques. the ascending projections originate from a group of subnuclei surrounding various components of the brachium conjunctivum, namely, the superficial lateral, dorsolateral, dorsomedial, and ventromedial subnuclei. the projections are predominantly ipsilateral and travel in the quintofrontal tract. they are primarily to the medial ...19901691747
[the pharmacokinetics of dihydrostreptomycin sulfate in domestic pigeons (columba livia gmel., 1789 var. domestica)].a 20% aqueous solution of dihydrostreptomycin sulfate in a dosage of 100 mg/kg b.w. is non-toxic for pigeons, although renal accumulation occurs. 12 hours after a single subcutaneous injection of 100 mg/kg b.w. the plasma concentration decreases to 3.64 micrograms/ml and therefore below the therapeutically effective concentration, while in birds suffering from salmonella infections plasma levels decrease to comparative concentrations (3.84 micrograms/ml) after only 8 hours. contrary to the direc ...19901699297
distribution, laminar location, and morphology of tectal neurons projecting to the isthmo-optic nucleus and the nucleus isthmi, pars parvocellularis in the pigeon (columba livia) and chick (gallus domesticus): a retrograde labelling study.retrograde transport of phaseolus vulgaris leucoagglutinin (pha-l), fluorogold, fast blue, rhodamine labelled microspheres, and horseradish peroxidase (hrp) was employed to study the distribution, laminar location within the optic tectum, and morphology of tectal cells projecting upon the isthmo-optic nucleus (ion) and the nucleus isthmi, pars parvocellularis (ipc), in the pigeon and chick. following injections into the ion, all retrograde markers labelled tecto-ion neurons and their dendrites i ...19911709956
organization of the cerebellum in the pigeon (columba livia): i. corticonuclear and corticovestibular connections.the projections of the cerebellar cortex upon the cerebellar nuclei and the vestibular complex of the pigeon have been delineated using wga-hrp as an anterograde and retrograde tracer. injections into individual cortical lobules (ii-ixa) produce a pattern of ipsilateral terminal labeling of both the cerebellar and vestibular nuclei. the pattern of corticonuclear projections indicates both a rostrocaudal and a mediolateral organization with respect to the lobules and is consistent with a division ...19911711053
organization of the cerebellum in the pigeon (columba livia): ii. projections of the cerebellar nuclei.the projections of the deep cerebellar nuclei in the pigeon have been delineated using autoradiographic and histochemical (wga-hrp) tracing techniques. a medial (cbm) and lateral (cbl) cerebellar nucleus are recognized and cbm may be further partitioned into internal, intermediate, and intercalate divisions. as in mammals, most extracerebellar projections of cbm travel in the fasciculus uncinatus (fu); the rest travel with those of cbl in the brachium conjunctivum (bc). in the pigeon, both of th ...19911711054
organization of the cerebellum in the pigeon (columba livia): iii. corticovestibular connections with eye and neck premotor areas.the connections of the cerebellar cortex with vestibular premotor neurons of the oculomotor and collimotor systems in the pigeon were delineated in experiments using wga-hrp as an anterograde and retrograde tracer. putative premotor neuron pools were identified by injections into the oculomotor (miii) and trochlear nuclei (miv) and into the most rostral portion of the cervical neck motor nucleus, nucleus supraspinalis (ssp). the retrograde data indicate that ipsilateral projections upon oculomot ...19911711055
localization of cardiac parasympathetic preganglionic neurons in the medulla oblongata of pigeon, columba livia: a study using fragment c of tetanus toxin.the binding fragment of tetanus toxin, fragment c, was injected into several different regions of the pigeon heart. retrogradely and/or transneuronally labeled cardiomotor parasympathetic preganglionic neurons were found in two separate nuclei within the medulla oblongata. the majority of fragment c-immunolabeled cells was confined to the caudal division of the nucleus ambiguus. this nuclear region is likely to be homologous to the ventrolateral nucleus of the external formation of the nucleus a ...19911713113
localization of calmodulin in epidermis and skin glands: a comparative immunohistological investigation in different vertebrate species.the study deals with the immunolocalization of calmodulin-reactive epithelial cells in different vertebrates (tinca tinca, ambystoma mexicanum, xenopus laevis, rana ridibunda, columba domestica, sus scrofa domestica, homo sapiens sapiens). the immunoperoxidase technique was performed on acetone fixed frozen sections using monoclonal (bf8) and polyclonal (acam) anti-calmodulin antibodies. we were able to differentiate 2 major types of staining patterns: 1. a more superficial epidermal staining in ...19911718122
a novel spinal pathway and other connections to the spinocerebellum in the pigeon.avian dorsal column nuclei do not project to the cerebellum. injections of fluorescent tracers into the spinocerebellum of homing pigeons (columba livia) disclosed a group of neurons located rostral to the dorsal column nuclei which receives spinal primary afferents, as confirmed by double-labeling experiments. since this group has some similarities to the mammalian group x (location medial to the restiform body, spinal afferents, efferents to the cerebellum), this name was adopted for the pigeo ...19911721857
the distribution of neuropeptides in the dorsomedial telencephalon of the pigeon (columba livia): a basis for regional subdivisions.the distribution of six neuropeptides [substance p (sp), leucine (leu5-) enkephalin (lenk), vasoactive intestinal polypeptide (vip), cholecystokinin (cck), neuropeptide y (npy), and somatostatin (ss)] in the dorsomedial telencephalon (hippocampal region) of the pigeon was studied by immunohistochemistry. all six peptides were found in fibers passing through the septo-hippocampal junction and along the medial wall of the hippocampal region. npy-, ss-, and vip-like staining of fibers was seen in t ...19911726107
occurrence of keratinophilic fungi on indian birds.keratinophilic fungi were isolated from feathers of most common indian birds, viz. domestic chicken (gallus domesticus), domestic pigeon (columba livia), house sparrow (passer domesticus), house crow (corvus splendens), duck (anas sp.), rose-ringed parakeet (psittacula krameri). out of 87 birds, 58 yielded 4 keratinophilic fungal genera representing 13 fungal species and one sterile mycelium. the isolated fungi were cultured on sabouraud's dextrose agar at 28 +/- 2 degrees c. chrysosporium speci ...19911726608
visual field organization and peck localization in the pigeon (columba livia).some aspects of the stimulus control of peck localization in the pigeon were examined using conditioning paradigms, visual occlusion procedures, and 'touch-screen' technology. birds were reinforced for pecks made to a small circular (target) stimulus projected upon a computer monitor and located within an electronically defined contingency area. the terminal location of each peck was monitored under binocular and monocular viewing conditions and when using either the frontal or lateral visual fi ...19911764206
calcitonin-gene related peptide is an evolutionarily conserved marker within the amniote thalamo-telencephalic auditory pathway.the distribution of neurons and fibers containing calcitonin-gene-related peptide (cgrp) was mapped in the thalamo-telencephalic auditory pathways of four amniote species, rats, pigeons (columba livia), caiman (caiman crocodilus), and turtles (pseudemys scripta). in colchicine-treated turtles and pigeons, numerous cgrp+ perikarya were observed in the auditory relay nucleus of the thalamus (n. reuniens of reptiles, and n. ovoidalis of birds). in pigeons, these neurons were most abundant in the ou ...19911765582
lectin binding pattern in the testes of several tetrapode vertebrates.the glycoconjugates of the testes of four species of vertebrates including amphibians (bufo calamita), reptiles (mauremys caspica), birds (columba livia) and mammals (mesocricetus auratus) were investigated by means of lectin histochemistry. spermatogonia of the animals studied were labelled by con a and wga. dba showed a specific affinity for the spermatogonia aal of the hamster indicating that dba might be an useful marker for this cell type. the acrosomes of the hamster spermatids were strong ...19911768726
[the occurrence of cryptococcus neoformans in fecal samples from birds kept in human living areas].with help of guizotia creatinine agar (syn. bird seed agar) cryptococcus (cr.) neoformans var. neoformans was isolated from 71 (7.7%) of 925 investigated droppings of birds kept within human living area. cr. neoformans was detected in droppings of 1.2% from 164 psittacines, in droppings of 1.7% from 118 budgerigars and in droppings of 18.4% from (carrier) pigeons. this yeast was not isolated from droppings of 13 small parrots, 10 eclectus parrots, 13 rosellas, 21 cockatiels, 6 polytelidus sp., 3 ...19911786044
ultrastructural changes of crop-sac and lactotrophs after systemic or intraventricular administration of drugs enhancing cholinergic transmission in pigeons.the ultrastructural effects of drugs enhancing, by different mechanisms, cholinergic transmission in the crop-sac (the target for prolactin secretion in birds) and the anterior pituitary lactotrophs, were studied in pigeons (columba livia). the systemic or intraventricular administration of physostigmine, carbachol and muscarine produced maximal crop-sac stimulation with milk-like secretion, as demonstrated by the observation of ultrastructural changes in the lactiferous areas through scanning a ...19911803944
directional dependence of intraocular transfer of stimulus detection in pigeons (columba livia).the eyes of the pigeon (columba livia) are positioned laterally in the head. thus, there is only a small area of binocular overlap, which constitutes the frontal visual field and a large area of monocular vision in the lateral visual fields. the conditions were examined under which intraocular transfer occurs in pigeons; that is, the transfer of information between both portions of the visual field of one eye. different groups of head-fixed birds learned to discriminate the presence of a bright ...19911815616
[morphometric analysis of the sciatic nerve and its principal branches in the pigeon (columba livia)].the methodological approach used in this study is to characterize the number, the density and the diameter distribution of myelinated fibers (mfs) and unmyelinated fibers (umfs) in sciatic nerve and its main branches of pigeon. the results have shown that the fiber composition is quite variable because in pigeon there are relatively mf with thin myelin sheaths and mf with thicker sheaths. our data suggest that morphometric analysis could represent a helpful methodological approach to better char ...19911822950
habituation to sound stimulation in detelencephalated pigeons (columba livia).habituation to sound stimulation was analyzed in terms of the functional role of the telencephalon in learning. sixteen pigeons were exposed to 1000-hz, 83-db, 1-s sound (stimulus a) at 30-s intervals until there was habituation of the exploratory and pre-exploratory responses. the learning criterion was 10 trials without the occurrence of these responses. twenty-four hours after habituation to stimulus a the birds were tested with a 500-hz, 85-db, 1-s sound (stimulus b). on the day following ha ...19911823233
effects of massive telencephalic lesions on the organization of behavior in pigeons (columba livia).the effects of massive lesions of the telencephalon on the behavioral repertoire of captive pigeons were investigated. the behavior of four birds with an intact telencephalon was compared to that of four birds submitted to ablation of telencephalic structures. behavioral audio recording was done according to previously defined categories in three daily sessions for fifteen days. experimental birds were followed up for one month. immediately after the lesion, operated birds showed decreases in th ...19911823266
primary structure of hemoglobin beta-chain from columba livia (gray wild pigeon).primary structure of beta-chain of pigeon is presented. it was determined by amino acid sequence analysis of intact beta-chain and its peptides obtained by the enzymatic and chemical cleavage. comparison of amino acid sequence of the chain with other available data shows beta 14 ile, beta 61 lys, and beta 113 ile as residues specific to pigeon. one important replacement at alpha 1 beta 1 contact is beta 55 met----ser.19911930630
comparative metabolic responses to prolonged cooling in precocial duck (anas domestica) and altricial pigeon (columba domestica) embryos.1. embryos and hatchlings of the duck and pigeon were exposed to a lowered temperature for 6 hr. the oxygen consumption (mo2) was measured before and after cooling and the ratio of the two was compared with that predicted for a temperature coefficient of 2 (arrhenius value). 2. late prenatal ducks kept the mo2 above the arrhenius value at 28 degrees c, while the mo2 of pigeon hatchlings became the same as the arrhenius value even at 32 degrees c. 3. thus, incipient homeothermic ability appears i ...19901970527
immunohistochemical analysis of the visual wulst of the pigeon (columba livia).the avian wulst, a laminated "bulge" in the dorsal telencephalon, contains several distinct regions. the posterolateral portion (visual wulst) has been proposed to be an avian equivalent of the mammalian striate cortex. the present study examines specific neurotransmitters and neuropeptides within the visual wulst by immunohistochemical techniques. antisera and monoclonal antibodies against choline acetyltransferase (chat), nicotinic acetylcholine receptor (nachr), tyrosine hydroxylase (th), ser ...19901979983
the eye of a procellariiform seabird, the manx shearwater, puffinus puffinus: visual fields and optical structure.the manx shearwater, puffinus puffinus, is a pelagic sea bird which feeds from the surface of the sea and by shallow surface and plunge dives. visits to breeding colonies are made at night. the mononuclear retinal field of the manx shearwater eye is 148 degrees wide and is asymmetric with respect to the optic axis. the nasal and temporal hemi-fields equal 65 and 83 degrees, respectively. the binocular field is long and narrow, and the central placement of the bill suggests that vision is used to ...19912054585
light and electron microscopic analyses of intraspinal axon collaterals of sympathetic preganglionic neurons.experiments were performed in pigeons (columba livia). sympathetic preganglionic neurons (spns) in the first thoracic spinal cord segment (t1) were identified electrophysiologically using antidromic activation and collision techniques and then intracellularly labeled with horseradish peroxidase (hrp). in 6 of 10 hrp-labeled spns, the site of axon origin and intraspinal axonal trajectory could be specified. in 2 of the 6 hrp-labeled axons, the peripherally projecting process branched intraspinall ...19912054640
central glucoregulation in the pigeon columba livia. effects of intraventricular injections of carbachol and catecholamines on blood glucose concentration.the effect of chemical stimulation of the central nervous system on glucoregulation was studied in pigeons (columba livia). adrenaline (30 nmol), noradrenaline (30 or 80 nmol) and carbachol (27 nmol) were injected in 1 microliter nacl directly into the lateral ventricle and changes in blood glucose concentration were measured. the intraventricular injection of adrenaline resulted in rapid hyperglycemia, whereas the injection of either carbachol or noradrenaline into the lateral ventricle did not ...19902101322
pathology of experimental sarcocystis falcatula infections of canaries (serinus canarius) and pigeons (columba livia).sarcocystis falcatula is an apicomplexan parasite with a broad range of avian intermediate hosts. the pathology and pathogenesis of infection with this parasite has been studied experimentally in the budgerigar (melopsittacus undulatus). the present study quantitatively examines the pathology of this parasite in canaries (serinus canarius) and pigeons (columba livia) and compares it with that found in budgerigars. the general progression of merogony and cyst formation is similar qualitatively to ...19902105389
effect of lh, fsh, lh + fsh and homoplastic pituitary extract on developing testis and epididymis of pigeon columba livia.ovine lh is needed for differentiation of juvenile leydig cells and for their maintenance and steroidogenic potential, while fsh is necessary for sertoli cell activity and spermatogonial multiplication suggesting that lh is steroidogenic hormone and fsh is gametogenic in the developing pigeon, c. livia. homoplastic pituitary extract is more potent than ovine lh + fsh in stimulating gametogenic and endocrine components of the developing testis.19902112510
behavioral effects of adrenaline and noradrenaline injected into the lateral ventricles of the pigeon (columba livia).the behavioral effects of intraventricular 1-microliter injections of adrenaline and noradrenaline (both in a concentration of 30 nmol/microliters) were examined in pigeons bearing cannulae chronically implanted into the lateral ventricles. injections of either catecholamine evoked immediate and intense bouts of feeding behavior, followed by long-lasting increases in sleep duration (50-90% higher than vehicle-treated subjects) in pigeons given free access to food during the observation period. p ...19902133020
thalamic origin of neuropeptide y innervation of the accessory optic nucleus of the pigeon (columba livia).immunohistochemical and tracing techniques were used in combination to reveal the source of a neuropeptide y-like immunoreactive (npy-li) plexus in the nucleus of the basal optic root (nbor) of the pigeon accessory optic system. injections of rhodamine-labeled latex microspheres into nbor produced retrograde labeling of a population of neurons interposed between the principal optic nucleus of the dorsolateral thalamus (equivalent to the mammalian dorsal lateral geniculate nucleus) and the ventra ...19902134848
the ventilatory movements of the avian pelvis and tail: function of the muscles of the tail region of the pigeon (columba livia).we have observed that birds of several different taxa move their tails in conjunction with sound production. these observations suggested to use that tail movements might also be associated with ventilation. since we hypothesized that rhythmic movements of the tail and pelvis will ventilate the lungs, the activities of tail, epaxial and cloacal muscles of the pigeon were examined. electromyograms (emgs) were recorded from these muscles while ventilation was monitored. a muscle was considered to ...19902143215
characterization of heterochromatin by sequential counterstain-enhanced fluorescence in three domestic bird species: meleagris gallopavo, columba livia domestica, and anser anser l.the karyotypes of three avian species--meleagris gallopavo, anser anser l., and columba livia domestica--were investigated by means of counterstain-enhanced fluorescence techniques (chromomycin a3/distamycin a/dapi followed by dapi/actinomycin d staining). a heterochromatin characterization of macro- and microchromosomes was performed. cma3-positive (gc-rich) regions in the turkey included the telomeres of chromosomes 1, 3, 4, and z. in the goose, the chromosome 2 was also cma3-bright at the tel ...19902250096
preliminary studies on the use of propofol in the domestic pigeon (columba livia).the anaesthetic propofol was investigated in domestic pigeons (columba livia). the agent was administrated intravenously, in one group of birds as an adjunct to ketamine hydrochloride, and careful monitoring was performed. the dose of 14 mg kg-1 of propofol was based on allometric scaling for its use as a sole agent. propofol anaesthesia was characterised by smooth rapid induction and good muscle relaxation but was only of short duration, ranging from two to seven minutes, and seemed to cause a ...19902267424
enterococcus columbae, a species from pigeon intestines.gram-positive cocci which dominate in the intestinal flora of domestic pigeons were found to constitute a new species of the genus enterococcus. the strains were most closely related to enterococcus cecorum, originally described as streptococcus cecorum, a carboxyphilic species from chicken intestines, and to enterococcus avium. the pigeon strains resemble e. cecorum and also many e. avium strains in their lack of group d antigen and in being more sensitive to nacl than other enterococci. the ty ...19902272492
[differences in macroglia of the spinal cord in various cold-blooded and warm-blooded animals].certain macroglial differences of the spinal cord in poikilothermal (rana esculenta, lacerta agilis) and in homoiothermal (columba livia, felis domesticus, macaca rhesus) animals have been revealed. a greater amount of glial satellites, surrounding neurons, motor centers of the spinal cord and appearance of new variety of astrocytes and oligodendrocytes are observed in the homoiothermal animals. it is supposed that the phenomenon mentioned indirectly reflects the evolutionary process of a more d ...19902275612
neural mechanisms of directional hearing in the pigeon.the directional sensitivity of single auditory neurons in the midbrain (nucleus mesencephalicus lateralis pars dorsalis) of the pigeon (columba livia) was studied, using acoustic free-field stimulation (usually pure tones) in the frontal hemifield. of a total of 337 units, 84.6% showed statistically significant changes of their responses as a function of sound azimuth. of these, most units respond maximally to sounds in a particular azimuthal range, each has its "best area". these neurons were c ...19902286242
pharmacokinetics and bioavailability of erythromycin in pigeons (columba livia).tissue and plasma concentrations were determined after intravenous and oral administration of erythromycin to pigeons to establish the pharmacokinetics and bioavailability of the drug. a short mean half-life of elimination of 0.9 h was found. the relative bioavailability after direct crop administration of erythromycin thiocyanate or erythromycin ethylsuccinate at a dosage rate of 100 mg/kg was less than 10%. at a drug concentration in drinking water of 1 g/l, erythromycin plasma levels were bar ...19902287027
pigeons with ablated pyriform cortex home from familiar but not from unfamiliar sites.homing behavior was tested in pigeons (columba livia) after removing a portion of the ventrolateral telencephalon, which receives extensive projections from the olfactory bulb and is comparable with the mammalian pyriform cortex. ablated pigeons show unaffected cardiac responses to odorous stimuli but altered homing behavior. after the operation, the birds were trained by repeated flock releases along with control birds from a site 40 km from the loft. after being released singly from this famil ...19902339121
key pecking operant conditioning in detelencephalated pigeons (columba livia).the present paper analyzed the acquisition and maintenance of key pecking reinforced with food by pigeons with massive ablation of telencephalon structures (detelencephalated pigeon). the subjects were adult pigeons maintained at 80% of their free feeding weight. expt. i analyzed the acquisition of key pecking by 3 previously detelencephalated pigeons and 3 normal controls. expt. ii investigated the effects of detelencephalation on the retention of learning through comparisons of pre- and postsu ...19902363842
toxoplasma gondii antibodies in common barn-owls (tyto alba) and pigeons (columba livia) in new southwestern new jersey during 1986 and 1987, common barn-owls and pigeons were captured on farmsteads and tested for toxoplasma gondii antibodies by a modified direct agglutination test. in 1986, 3/28 (10.7%) adult and 0/124 nestling owls tested positive at titers of greater than or equal to 1:40. additionally, 2/34 (5.9%) pigeons tested had t. gondii antibodies at titer of 1:320. in 1987, 9/38 (27.3%) adult and 18/80 (22.5%) nestling owls tested positive at titers of greater than or equal t ...19902382386
hematological changes produced by lindane (gamma-hch) in six species of birds.hematological changes were studied after oral administration of lindane (gamma-hexachlorocyclohexane) at 5 mg/kg body weight twice in 1 week in 6 species of agriculturally important birds: house sparrow, baya weaver bird, common myna, rose-ringed parakeet, blue rock pigeon and domestic duck. lindane induced anemia in the birds as judged by reduced rbc count, hematocrit and hemoglobin content with corresponding changes in mcv, mch and mchc. bleeding and clotting time were markedly prolonged. sple ...19862424143
a golgi study of the isthmic nuclei in the pigeon (columba livia).the isthmic nuclei of the pigeon were studied with the use of three different golgi techniques. the nucleus isthmo-opticus (io) consists of a single cell type in which all dendrites of one neuron take the same direction and ramify at identical distances from the perikaryon to form dense dendritic arborizations. the cell bodies of the io neurons form two parallel layers. the dendrites of these neurons always extend to the area between the two layers so that the dendritic arborizations of opposite ...19872438047
intraspinal substance p-containing projections to the sympathetic preganglionic neuropil in pigeon, columba livia: high-performance liquid chromatography, radioimmunoassay and electron microscopic evidence.the present study uses quantitative and electron microscopic methods to investigate the hypothesis that intraspinal substance p-sympathetic preganglionic neuron circuitry exists in vertebrates. radioimmunoassay and high-performance liquid chromatography were used to: (1) characterize the chemical nature of the substance p-like immunoreactivity in the sympathetic preganglionic neuropil; and (2) quantify the relative contributions of brain stem, primary sensory and intraspinal neurons to the subst ...19882459629
projections of the nucleus of the tractus solitarius in the pigeon (columba livia).with the aid of autoradiographic and histochemical (wga-hrp) tracing techniques, the projections of the nucleus of the tractus solitarius (nts) in the pigeon have been delineated and related to the viscerotopic organization of the nucleus. as in mammals, nts projects to both brainstem and forebrain structures. at medullary levels, projections were seen to nts itself, to the dorsal motor nucleus of the vagus and to the subjacent and more ventral reticular formation. there is a substantial project ...19882464007
cerebellar connections of the trigeminal system in the pigeon (columba livia).wheat germ-agglutinin conjugated horseradish peroxidase (wga-hrp) was used to delineate trigeminocerebellar connections in the pigeon. subnucleus oralis of the nucleus of the descending trigeminal tract (nttd) is the exclusive origin of trigeminal mossy fibers, which terminate in lobules viii and ixa. the trigemino-olivary projection originates from subnucleus interpolaris of nttd, but the existence of an additional pathway relaying in the adjacent lateral reticular formation (i.e. the plexus of ...19892473825
studies of solitary semicircular canal hair cells in the adult pigeon. ii. voltage-dependent ionic conductances.1. the ionic conductances present in putative type ii hair cells enzymatically dissociated from the anterior, posterior, and lateral semicircular canal cristae of the white king pigeon (columba livia) vestibule were studied under whole cell voltage clamp. 2. two classes of voltage-dependent potassium conductances were distinguishable on the basis of the time course of activation and inactivation and pharmacologic sensitivity. the rapid potassium conductance, ia, as inhibited by 6 mm 4-aminopyrid ...19892478671
chemically specific retinal ganglion cells collateralize to the pars ventralis of the lateral geniculate nucleus and optic tectum in the pigeon (columba livia).immunohistochemical and retrograde tracing techniques were combined to study the retinal ganglion cells which project to the pars ventralis of the lateral geniculate nucleus (glv) in the pigeon. using two different fluorescent tracers, two histochemically-distinct populations of ganglion cells were found to project to both the glv and the optic tectum. the first population of ganglion cells exhibited tyrosine hydroxylase-like immunoreactivity and represented about 20% of all ganglion cells which ...19892484822
[presence of pathogenic yeasts in the feces of the semi-domesticated pigeon (columba livia, gmelin 1789, urban type) from the city of turin].the results of a survey on the presence of pathogenic yeasts in pigeon droppings collected in turin, are shown. the study was carried out in 8 densely populated areas, where human-animal contact is highest. a total of 427 pigeon dropping samples, most of which fresh, were collected. 550 yeast colonies, clinically interesting or at least pathologically significant, were isolated by the identification routine methods. the yeasts belong to the following species: candida albicans, c. humicola, c. kr ...19892487001
a prolactin-inducible gene product which is a member of the calpactin/lipocortin family.the major prl-inducible gene product from pigeon cropsac was cloned from lambda gt11 and sequenced by chain termination. the sequence of pgcp35 includes an open reading frame which yields a polypeptide which highly similar to mammalian calpactin ii (lipocortin i). like the other calpactins, the deduced protein (cp35) consists of a 4-fold repeating structure which has a conserved core characteristic of a large group of calcium-dependent membrane-binding proteins. prl-stimulated cropsac expresses ...19892526923
total body haematocrit iron kinetics and erythrocyte life span in pigeons (columba livia).1. the mean pigeon erythrocyte life span was found to be 17-25 days by cr51-labeled erythrocytes and 21 +/- 3.4 days by iron kinetics. 2. total red blood cell volume has been calculated by cr51-labeled erythrocytes while total plasma volume was determined both by a dye method and iron kinetic data. from these results total blood volume and total body haematocrit were found to be 0.090 +/- 0.002 ml/g body wt and 36 +/- 4.3%, respectively. 3. venous haematocrit, haemoglobin concentration, erythroc ...19892566412
interspecific variation in sugar and amino acid transport by the avian cecum.previous studies of cecal sugar and amino acid transport in the domestic chicken led to a widely held generalization that the avian cecum is unimportant as a site of nutrient transport. in fact, we found that the uptake capacity of the cecum for hexose sugars and amino acids is substantial in some species of birds. cecal transport of glucose was measurable in all five study species (canada goose, sage grouse, domestic chicken, red-necked phalarope, and rock dove), approached or exceeded intestin ...19892575122
neurotransmitters, receptors, and neuropeptides in the accessory optic system: an immunohistochemical survey in the pigeon (columba livia).immunohistochemical techniques were used to survey the distribution of several conventional transmitters, receptors, and neuropeptides in the pigeon nucleus of the basal optic root (nbor), a component of the accessory optic system. amongst the conventional neurotransmitters/modulators, the most intense labeling of fibers/terminals within the nbor was obtained with antisera directed against glutamic acid decarboxylase (gad) and serotonin (5-ht). moderately dense fiber plexuses were seen to label ...19892577270
effect of 5-htp and ketanserine on the aggressive reaction induced by food competition in dominant and submissive pigeons (columba livia).there is abundant literature about the effects of manipulation of 5-hydroxytryptamine (5-ht) systems on some killer behaviors as well as on social isolation and shock-induced aggression in rodents. in this work we have analyzed the effect of 5-ht manipulation on the aggressive behavior induced by food competition in undernourished pigeons. adult males (n = 12) were caged individually and their body weight kept at 80-85% by a restricted diet. these were divided in pairs which were exposed daily t ...19892597343
light microscopic and ultrastructural localization of gaba-like immunoreactive input to retrogradely labeled sympathetic preganglionic neurons.the organization of gamma-aminobutyric acid-like immunoreactive (gaba-lir) processes was studied within the sympathetic preganglionic neuropil of male sprague-dawley rats and pigeons (columba livia). sympathetic preganglionic neurons were retrogradely labeled following horseradish peroxidase (hrp) injections into either the adrenal medulla or superior cervical ganglion in rats or into the avian homologue of the mammalian stellate ganglion (paravertebral ganglion 14) in pigeons. gaba-lir staining ...19892598044
the presence of q-fever antibodies in teheran's pigeons (columba domestica).teheran's wild city pigeons were tested for q-fever antibodies. 12 out of 152 sera showed a positive reaction.19892599391
primary structure of hemoglobin alpha-chain of columba livia (gray wild pigeon).primary structure of hemoglobin of alpha-chain of columba livia is presented. the separation of alpha-chain was obtained from globin by ion-exchange chromatography (cmc-52) and reversed-phase hplc (rp-2 column). amino acid sequence of intact as well as tryptic digested chain was determined on gas-phase sequencer. structure is aligned homologously with 21 other species. among different exchanges, positions alpha 24 (tyr----leu), alpha 26 (ala----gly), alpha 32 (met----leu), alpha 64 (asp----glu), ...19892610857
the relation between head and apparent visual field motion in the pigeon (columba livia).in order to study the relationship between the apparent motion of the visual field as a function of head motion, we have developed an equation that describes the apparent displacement of objects in the visual field produced by a general movement of the head consisting of a rotation plus a translation. we then used this equation to simulate the apparent motion of the visual field of a pigeon produced by rotation of the head about axes parallel to those of its anterior semicircular canals.19892620192
seasonal differences in glucose tolerance and insulin response of pinealectomized pigeons (columba livia).the effects of a glucose tolerance test (gtt) and an insulin response test (irt) on blood glucose levels were evaluated in pinealectomized and nonpinealectomized pigeons during the breeding and nonbreeding months. the tests revealed increased glucose tolerance and insulin sensitivity in pinealectomized birds during the breeding season. in the nonbreeding season, both the pinealectomized and the control birds tended to show more or less similar responses for both gtt and irt. these changes confir ...19892651644
an immunohistochemical study on the distribution of endocrine cells in the gastrointestinal tract of domestic pigeon, (columba livia var domestica).the endocrine cells in the gastrointestinal tract of the domestic pigeon (columba livia var domestica) were studied immunohistochemically, and their distribution and relative frequencies were determined. in the proventriculus, moderate numbers of somatostatin- and numerous gastrin-releasing polypeptide (grp)-immunoreactive cells were found. no immunoreactive cells were detected in the gizzard. in the pyloric region, many motilin-immunoreactive cells were found in addition to numerous somatostati ...19892672658
pharmacokinetics and bioavailability of ronidazole from a prolonged release tablet in the homing pigeon (columba livia).the pharmacokinetics of ronidazole and the bioavailability of a prolonged release tablet were studied in the homing pigeon. after intravenous administration of 5 mg ronidazole, the drug plasma concentration profile fitted a one-compartment open model. the mean half-life of the drug was 11 h and the volume of distribution was 0.86 l/kg. total body clearance was 0.056 l/h/kg. a sustained release matrix tablet exhibited prolonged drug release in vitro. after oral administration of the matrix tablet ...19892704060
head orientation in pigeons: postural, locomotor and visual determinants.we have determined the pigeon's head orientation for two postures and two locomotor activities that do not involve a specific visual stimulus. using a high-speed cine camera, we filmed four pigeons (columba livia) while (1) flying, (2) walking, (3) perching and (4) standing on a flat surface. under these conditions, the head orientation is relatively constant, allowing us to estimate the normal horizon of the visual field and thus the horizontal meridian of the retina. measurements of the latera ...19892758315
[light microscopic and ultrastructural study of the lower olivary complex in the pigeon (columba livia)].the normal morphology of neurones and neuropile of the inferior olivary complex (loc) in a pigeon (columbia livia) was investigated by a light and electron microscope. the light microscopic analysis on the basis of the histological techniques of vissl, gldgi-rio hortega showed that olivary neurons had moderate mean dimensions and moderately branched dendrite tree, but single neurons with a model for dendrite branches were encountered similar to the second type of neurons in mammals. axo-somatic ...19892759008
osmoregulation and body fluid compartmentalization in dehydrated heat-exposed pigeons.osmoregulatory and volume-regulatory responses of heat-acclimated pigeons (columba livia) were studied during normal hydration and dehydration combined with heat exposure. dehydrated heat-exposed pigeons (exposure to 50 degrees c following 48 h of water deprivation; 16-18% mass loss) could recover 97% of their initial body mass within 30 min of free drinking at the end of heat exposure. at the end of heat exposure, body temperature increased by 3 degrees c and hematocrit increased by 12.5%. seru ...19892764160
musculotopic innervation of the primary flight muscles, the pectoralis (pars thoracicus) and supracoracoideus, of the pigeon (columba livia): a wga-hrp study.the distribution of motoneurons innervating the primary depressor and elevator muscles of the wing of the domestic pigeon (columba livia) was studied by using the retrograde axonal tracer lectin-conjugated horseradish peroxidase (wga-hrp). injection of wga-hrp into the pectoralis (pars thoracicus) labeled neurons in the ventromedial corner of the lateral motor column of the spinal cord. these neurons were arranged in a column extending from spinal segment x or xi to spinal segment xii or xiii. t ...19892774211
["ghost" bodies and calcification in experimental coronary artery atherosclerosis in pigeons].nineteen young pigeons (columba livia domestica) fed on cholesterol (0.5 g per day per bird) for 31 weeks were studied by electron microscopy focusing on calcification in coronary artery atherosclerosis. after 24-31 weeks of cholesterol feeding, smooth muscle cells (smcs) in the media layer showed an obvious proliferation. many of these cells had bulbous cytoplasmic pseudopod-like processes connecting with the cell body by narrow stalks. many of the cytoplasmic pseudopodia as well as the detache ...19892776250
neuromuscular organization of the pectoralis (pars thoracicus) of the pigeon (columba livia): implications for motor control.the pectoralis (pars thoracicus) of the domestic pigeon (columba livia) is divisible into two anatomical parts, the pars sternobrachialis (sb) and the pars thoracobrachialis (tb). innervation to this complex is from rostral and caudal branches of the brachial ventral cord. in four anesthetized pigeons, the distribution of muscle units associated with each nerve branch was mapped after prolonged stimulation of each nerve and subsequent analysis for muscle fiber glycogen. an additional three anima ...19892782625
[morphology of glial cells in the lower olivary complex of the pigeon (columba livia). i. astrocytes].the morphologic peculiarities of astrocytes in the lower olivary complex (loc of a pigeon were examined at light and electron microscopic level. usage of histological technique established the presence of three varieties: fibrous, real protoplasmic and covered type of astrocytes. in loc of a pigeon most of astrocytes, observed by the electron microscope, possessed in their cytoplasm bunches of filaments, which passed and proceeded along side to astrocytic arborizations parallelly. other type of ...19892806177
[morphology of glial cells in the lower olivary complex of the pigeon (columba livia). ii. oligodendrocytes].the morphologic peculiarities of oligodendrocytes in the lower olivary complex (loc) of a pigeon were examined at light and electron microscopy level. the analysis on the basis of the applied histological techniques (staining with cresyl-violet and silver impregnation according to goldgi-rio hortega) showed that oligodendrocytes were small rounded cells with nuclei stained more darkly than those of astrocytes. oligodendrocytic arborizations were thin, slightly ramified and small in number. the p ...19892806178
studies of solitary semicircular canal hair cells in the adult pigeon. i. frequency- and time-domain analysis of active and passive membrane properties.1. hair cells were enzymatically dissociated from the neuroepithelium (cristae ampullares) of the semicircular canals of white king pigeons (columba livia). those hair cells determined to be type ii by an anatomic criterion, the ratio of the minimum width of the neck to the width of the cuticular plate, were studied with the use of the whole cell patch-clamp technique. 2. the mean +/- sd zero-current membrane potential, vz, was found to be -54 +/- 12 mv for anterior crista hair cells (n = 71), - ...19892809711
distribution of tyrosine-hydroxylase (th)-immunoreactive neurons in the diencephalon of the pigeon (columba livia domestica).the distribution of tyrosine-hydroxylase (th)-immunoreactive cell bodies and fibers in the diencephalon has been investigated with immunohistological techniques in the pigeon. the results suggest that th is present in a number of morphologically distinct neuronal systems. preoptic and hypothalamic th neurons were subdivided into a medial periventricular and a lateral group. the medial group starts with a rostral collection of small cells in the preoptic region. a significantly larger collection ...19872881951
the effects of ligation of the oesophagus on body and brain temperature in pigeons.1. we measured brain and colonic temperatures in adult pigeons (columba livia) with or without oesophageal ligation, and with or without simultaneous eye covering at ambient temperatures between 24 degrees c and 45 degrees c. 2. colonic and brain temperatures rose at the higher ambient temperatures; the temperature elevations were no different in pigeons with oesophageal ligation, compared to sham-operated controls. the presence of simultaneous eye covering also had no effect on colonic or brain ...19872887395
catecholaminergic subpopulation of retinal displaced ganglion cells projects to the accessory optic nucleus in the pigeon (columba livia).in birds, displaced ganglion cells (dgcs) constitute the exclusive source of retinal input to the nucleus of the basal optic root (nbor) of the accessory optic system. tyrosine-hydroxylase (th) immunoreactivity was examined in the pigeon retina after injections of rhodamine-labeled microspheres into the nbor. a population of about 400 dgcs was observed in each case to exhibit both th immunoreactivity and rhodamine bead fluorescence. this corresponded to about 10-15% of the total number of identi ...19882896205
reproduction of rock pigeon exposed to extreme ambient temperatures.1. the breeding biology of rock pigeon (columba livia) exposed to ambient temperatures (ta) between 50 and 60 degrees c was investigated. 2. four families accomplished three complete life cycles after long term daily exposure to extreme ta, with about 100% success. 3. the steady state temperatures in the nest were 60, 58, 53 and 44.6 degrees c in the air, substrate surface, underwing, and in the egg's microenvironment, respectively. 4. at thermal conditions between 30 and 60 degrees c, egg tempe ...19882901322
on the histochemical characterization and distribution of fast and slow muscle fibers in certain avian skeletal muscles.histochemical techniques based upon the ph sensitivity of myofibrillar adenosine triphosphatase are used to differentiate avian skeletal muscle fibers as either fast or slow. pars thoracica m. pectoralis (pm) of several avian species, pars cranialis m. latissimi dorsi (ldcr) of the japanese quail, and m. tensor propatagialis (tp) of the domestic pigeon are examined. fast fibers predominate in the pm, and slow fibers in the ldcr. the tp shows marked internal variation in the distribution of muscl ...19872951958
Displaying items 101 - 200 of 1759