| water conservation in xerophilic birds. | adaptation of birds to dry climates involves decrease in relative evaporative water loss (mechanism unknown); decrease in gfr; and high urine osmolality in the dehydrated state in conjunction with cloacal resorption parameters, which allows the urine to enter the cloaca without a further water loss. the net result of the adaptations is such that the best adapted birds, such as the budgerygah (12) and the zebra finch (13) fed dry seeds alone can live without water. similar features have been obse ... | 1976 | 977281 |
| structural-functional correlations in the kidneys and observations of colon and cloacal morphology in certain australian birds. | 1. variations in renal microstructure between the zebra finch and senegal dove were consistent with their relative renal concentrating abilities (urine/plasma ratios of 2-8 and 1-7, respectively). compared with dove kidneys, those of the finch contained a higher fraction of mammalian-type nephrons (with henle's loops), and a lower fraction of reptilian-type nephrons (without loops). 2. singing honeyeaters concentrated their urine almost as well as zebra finches, although honeyeater kidneys were ... | 1975 | 1213951 |
| choroid plexus, ependyma and arachnoidea express receptors for vitamin d: differences between "seasonal" and "non-seasonal" breeders. | autoradiographic studies with [3h]1,25-dihydroxyvitamin d3 demonstrated nuclear high affinity binding sites (receptors) in epithelial cells of choroid plexus, ependyma and arachnoid in "seasonal" breeders of various vertebrate phyla, namely xiphophorus helleri, hyla crucifer, xenopus laevis, bufo woodhousei, chrysemys scripta, anolis carolinensis, nerodia sipedon and phodopus sungorus, but vitamin d receptors were undetectable in these tissues in non-seasonal breeders, such as zebra finch, labor ... | 1992 | 1329147 |
| perception of conspecific faces by budgerigars (melopsittacus undulatus): i. natural faces. | perception of faces by 4 budgerigars (melopsittacus undulatus), a species of small parrot, was studied with a same-different discrimination task. reaction times were taken as a measure of the similarity between pairs of faces and analyzed with multidimensional scaling to reveal patterns of similarity among the faces. the perception of natural faces was tested to determine which characteristics were perceptually salient. color, patterns of markings, darkness of the iris, and size of the pupil cor ... | 1992 | 1395490 |
| immunoreactive vasotocin in the zebra finch brain (taeniopygia guttata). | the distribution of vasotocin (vt)-immunoreactive cells and fibers in the zebra finch brain was studied with immunocytochemical techniques. a large number of vt-immunoreactive cells was found in the nucleus preopticus anterior and nucleus paraventricularis. in the lateral parts of the hypothalamus diffusely organized vt-immunoreactive cells were present. some of these cells were found close to and embedded in the optic tract. an extra-hypothalamic parvocellular cell group was found at the level ... | 1992 | 1424081 |
| distribution and developmental change in [3h]mk-801 binding within zebra finch song nuclei. | in many songbirds, vocal learning depends upon appropriate auditory experience during a sensitive period that coincides with the formation and reorganization of song-related neural pathways. because some effects of early sensory experience on neural organization and early learning have been linked to activation of n-methyl-d-aspartate (nmda) receptors, we measured binding to this receptor within the neural system controlling song behavior in zebra finches. quantitative autoradiography was used t ... | 1992 | 1460469 |
| song presentation induces gene expression in the songbird forebrain. | we investigated the participation of genomic regulatory events in the response of the songbird brain to a natural auditory stimulus of known physiological and behavioral relevance, birdsong. using in situ hybridization, we detected a rapid increase in forebrain mrna levels of an immediate-early gene encoding a transcriptional regulator (zenk; also known as zif-268, egr-1, ngfi-a, or krox-24) following presentation of tape-recorded songs to canaries (serinus canaria) and zebra finches (taeniopygi ... | 1992 | 1495970 |
| auditory perception of conspecific and heterospecific vocalizations in birds: evidence for special processes. | budgerigars (melopsittacus undulatus), canaries (serinus canaria), and zebra finches (poephila guttata castanotis) were tested for their ability to discriminate among distance calls of each species. for comparison, starlings (sturnus vulgaris) were tested on the same sounds. response latencies to detect a change in a repeating background of sound were taken as a measure of the perceptual similarity among calls. all 4 species showed clear evidence of 3 perceptual categories corresponding to the c ... | 1992 | 1555398 |
| immunocytochemical localization of androgen receptors in the male songbird and quail brain. | the distribution of androgen receptors was studied in the brain of the japanese quail (coturnix japonica), the zebra finch (taeniopygia guttata), and the canary (serinus canaria) by immunocytochemistry with a polyclonal antibody (ar32) raised in rabbit against a synthetic peptide corresponding to a sequence located at the n-terminus of the androgen receptor molecule. in quail, androgen receptor-immunoreactive cells were observed in the nucleus intercollicularis and in various nuclei of the preop ... | 1992 | 1578004 |
| testosterone facilitates some conspecific song discriminations in castrated zebra finches (taeniopygia guttata). | an experiment was designed to test for the influence of testosterone on song discriminations. we found that testosterone did have an effect, which interacted with practice and the nature of the stimuli. fourteen adult castrated zebra finches (taeniopygia guttata) were grouped into seven pairs. in each pair, one bird was implanted with a testosterone-filled silastic tube and the other was implanted with an empty silastic tube. they were then trained on a go/no-go operant task to discriminate betw ... | 1992 | 1741392 |
| song-selective auditory circuits in the vocal control system of the zebra finch. | birdsong is a learned behavior controlled by a distinct set of brain nuclei. the song nuclei known as area x, the medial nucleus of the dorsolateral thalamus (dlm), and the lateral magnocellular nucleus of the anterior neostriatum (l-man) form a pathway that plays an important but unknown role in song learning. one function served by this circuit might be auditory feedback, which is critical to normal song development. we used single unit recordings to demonstrate that all three of these nuclei ... | 1991 | 1763048 |
| sound localization in small birds: absolute localization in azimuth. | nine small birds of 3 species (melopsittacus undulatus, serinus canarius, and poephila guttata) were trained in an operant procedure to fly to sound sources for food reward. the angle between the 2 sound sources was varied on a session-by-session basis, and threshold (i.e., minimum resolvable angle) was taken as the angle that corresponded to a performance level of 75% correct. in all, thresholds were calculated for pure tones of 5 different frequencies, noise bands of 3 different spectral compo ... | 1991 | 1860306 |
| perception of distance calls by budgerigars (melopsittacus undulatus) and zebra finches (poephila guttata): assessing species-specific advantages. | budgerigars (melopsittacus undulatus) and zebra finches (poephila guttata) share a common functional class of vocalizations called distance calls. the perception of species-specific distance calls by both species was measured with a habituation-dishabituation operant paradigm. changes in discrimination performance were noted as listening conditions were modified or stimulus properties were altered. both species showed better performance for calls of their own species. for zebra finches this tend ... | 1991 | 2032457 |
| detection of auditory sinusoids of fixed and uncertain frequency by budgerigars (melopsittacus undulatus) and zebra finches (poephila guttata). | three budgerigars and three zebra finches were tested for their ability to detect sinusoidal stimuli in the presence of broadband noise. masked thresholds for 1, 2, and 4 khz pure tones were measured with a fixed frequency condition, in which only one test frequency was presented in a session, and with an uncertain frequency condition, in which three signal frequencies were presented in random order in one session. the critical signal/noise ratios obtained in the fixed frequency condition were s ... | 1990 | 2076970 |
| detection of gaps in noise by budgerigars (melopsittacus undulatus) and zebra finches (poephila guttata). | temporal gap detection thresholds were obtained for two species of birds, budgerigars and zebra finches, which are known to have different auditory filter bandwidths. both species showed gap detection thresholds of about 2.5 msec for broadband noise stimuli. comparing octave bands of noise centered at 1, 3, and 5 khz, zebra finches showed the smallest gap thresholds for the noise band centered at 5 khz whereas budgerigars showed the smallest gap detection thresholds for the noise band centered a ... | 1990 | 2076971 |
| a retrospective study of disease and mortality in zebra finches. | few published reports exist describing morbidity and mortality in domestic zebra finch colonies maintained in a laboratory animal setting. a retrospective study of clinical disease and mortality in quarantined adult zebra finches was performed. animals were observed during the 2 week quarantine period and for at least 1 month afterwards (42 days). signs of disease, including feather and beak abnormalities, oculonasal discharge, increased respiratory rate or stridor, abdominal enlargement, pasty ... | 1990 | 2166869 |
| distribution of aromatase in the brain of the japanese quail, ring dove, and zebra finch: an immunocytochemical study. | an immunocytochemical peroxidase-antiperoxidase procedure using a purified polyclonal antibody raised against human placental aromatase was used to localize aromatase-containing cells in the brain of three avian species: the japanese quail, the ring dove, and the zebra finch. in quail and dove, immunoreactive cells were found only in the preoptic area and hypothalamus, with a high density of positive cells being present in the medial preoptic area, in the septal area above the anterior commissur ... | 1990 | 2262592 |
| antiestrogens fail to prevent the masculine ontogeny of the zebra finch song system. | early treatment with the antiestrogen, tamoxifen, fails to block the ontogeny of the male zebra finch song system which is hypothesized to occur as a result of early estradiol action. in experiment 1, two other antiestrogens, ly117018 or ci628, or vehicle was administered daily to zebra finch chicks for the first 20 days after hatching at which time the males were castrated. comparisons of experimental and control brains at 60 days revealed that neither antiestrogen prevented the masculinization ... | 1990 | 2272479 |
| sex- and age-related differences in the activity of testosterone-metabolizing enzymes in microdissected nuclei of the zebra finch brain. | many effects of testosterone (t) in the zebra finch (taeniopygia guttata) can be mimicked by t-metabolites, mainly estradiol and 5 alpha-dihydrotestosterone. we have therefore studied the neuroanatomical distribution of testosterone-metabolizing enzymes by means of the palkovits punch technique combined with radioenzyme assay in the brain of adult and young male and female zebra finches. the activity of these enzymes was studied by a one-point assay in 5 nuclei of the song system (x, man, hvc, r ... | 1990 | 2334847 |
| scanning electron microscope study of neuromuscular junctions in different muscle fiber types in the zebra finch and rat. | examination by scanning electron microscopy revealed differences between neuromuscular junctions in the muscle fibers of the zebra finch (bird) and rat. the neuromuscular junctions between the anterior and posterior latissimus dorsi muscles of the zebra finch were compared. the junctions of the former, exclusively slow tonic fibers, were small and numerous along the long axis of a single muscle fiber. the synaptic depressions per junction were few. the junctions of the latter, exclusively fast t ... | 1990 | 2390332 |
| effects of castration and testosterone treatment on the activity of testosterone-metabolizing enzymes in the brain of male and female zebra finches. | recently, we described the distribution of testosterone-metabolizing enzymes (i.e., aromatase, 5 alpha- and 5 beta-reductases) in the zebra finch (taeniopygia guttata) brain using a sensitive radioenzyme assay combined to the palkovits punch method. a number of sex-differences in the activity of these enzymes were observed especially in nuclei of the song-control system. the hormonal controls of these differences have now been analyzed by gonadectomizing birds of both sexes and by giving them a ... | 1990 | 2394994 |
| androstenedione modulation of monoamine levels and turnover in hypothalamic and vocal control nuclei in the male zebra finch: steroid effects on brain monoamines. | levels of norepinephrine (ne), dopamine (da), serotonin and the latter's primary metabolite, 5-hydroxyindoleacetic acid, were measured in two hypothalamic and 6 vocal control areas in the brains of male zebra finches. ne and da turnover in these areas were also estimated using alpha-methylparathyrosine. males were castrated for at least 3 weeks and then received an implant of androstenedione (ae) or a control implant of cholesterol. each male was then housed with a female for at least one week. ... | 1988 | 2460189 |
| the acetylcholine and catecholamine contents in song control nuclei of zebra finch during song ontogeny. | the acetylcholine (ach), dopamine (da) and noradrenaline (na) concentrations in the song control nuclei, the magnocellular nucleus of the anterior neostriatum (man), the caudal nucleus of the ventral hyperstriatum (hvc) and the robust nucleus of the archistriatum (ra) were measured using high performance liquid chromatography (hplc) at 5 different ages (30, 40, 50, 60 and 90 days after hatching). ach concentration of these nuclei increased markedly during the critical period for learning and dec ... | 1989 | 2743564 |
| structure and concentrating ability in the avian kidney. | we quantified various aspects of the morphology of the kidney in seven bird species and related these measures to urinary concentrating ability (the concentration of ureteral urine in dehydrated animals) for six of the species. kidney mass, number of glomeruli, and number of medullary cones all tended to increase with body mass. smaller birds, with smaller kidneys, had smaller nephrons with smaller glomeruli. lengths of medullary cones tended to increase with body mass and were exceptionally lon ... | 1989 | 2916702 |
| estrogen receptor levels in hypothalamic and vocal control nuclei in the male zebra finch. | estrogens play an important role in the activation and differentiation of vocal behavior in male zebra finches. in the present experiment, we conducted a series of in vitro binding assays to quantify estrogen receptor concentrations in individual hypothalamic and vocal control nuclei. receptor concentrations were measured in cytosol fractions obtained from castrated males and, since adrenalectomy is not a viable possibility in this species, in castrated males treated with 1,4,6-androstatriene-3, ... | 1988 | 3167582 |
| paradoxical hypermasculinization of the zebra finch song system by an antiestrogen. | exogenous estrogens, when administered to hatchling female zebra finches, masculinize the morphology and function of their neural vocal control system. the first of two experiments evaluated whether tamoxifen citrate is an antiestrogen in zebra finches, and the second determined whether it would block the masculinization hypothesized to be caused in hatchling males by the males' endogenous estradiol. in the first experiment adult female zebra finches were ovariectomized and injected for 10 days ... | 1988 | 3235068 |
| hearing in passerine and psittacine birds: a comparative study of absolute and masked auditory thresholds. | operant conditioning and a psychophysical tracking procedure were used to measure auditory thresholds for pure tones in quiet and in noise for seven species of small birds--the budgerigar, canary, cockatiel, european starling, song sparrow, swamp sparrow, and the zebra finch. audibility curves are roughly similar among the seven birds, with the maximum sensitivity between 2 and 5 khz and poorer sensitivity outside this narrow region. critical ratios (signal-to-noise ratio at masked threshold) we ... | 1987 | 3568610 |
| ontogenetic changes in the pattern of androgen accumulation in song-control nuclei of male zebra finches. | the present study examines the development of androgen accumulation in cells of two brain nuclei that are involved in controlling vocal behavior in zebra finches (poephila guttata). hvc (caudal nucleus of the ventral hyperstriatum) is involved with vocal production in adult birds, and man (magnocellular nucleus of the anterior neostriatum) is involved with the initial ability to learn song. in both of these nuclei there is an increase in the proportion of cells that are labeled by systemic injec ... | 1987 | 3572388 |
| sexual differentiation of androgen accumulation within the zebra finch brain through selective cell loss and addition. | in zebra finches males, but not females, respond to gonadal androgens with the production of a stereotyped courtship song. corresponding to this dimorphism in hormone sensitivity, two song-related neural regions, magnocellular nucleus of the anterior neostriatum (man) and hyperstriatum ventralis pars caudalis (hvc), have more cells that accumulate androgens in males than in females. the early hormonal environment establishes these sex differences in the brain and behavior such that females treat ... | 1987 | 3584563 |
| arousal enhances [14c]2-deoxyglucose uptake in four forebrain areas of the zebra finch. | the activity pattern of the forebrain of male zebra finches was investigated by the [14c]2-deoxyglucose (2-dg) method in 4 different behavioral situations. sitting alone in the cage (control); courtship by experienced birds; first courtship of inexperienced birds (100 days of age), and chasing the birds around the cage. the primary sensory areas (ectostriatum, field l) were active above background in each experiment. vocal-motor control areas were at background activity (ra, hvc, man), or below ... | 1986 | 3768137 |
| estrogen establishes sex differences in androgen accumulation in zebra finch brain. | in zebra finches, androgens stimulate the production of a learned courtship song in males but not in females. corresponding to this behavioral dimorphism, neural regions controlling the learning and production of song are much larger in males than in females. in two of these song-related brain regions, magnocellular nucleus of the anterior neostriatum (man) and hyperstriatum ventrale pars caudale (hvc), males have a larger percentage of androgen-accumulating cells than females. since sex differe ... | 1986 | 3958792 |
| brain gangliosides in birds with different types of postnatal development (nidifugous and nidicolous type). | developmental profiles of 14 different brain gangliosides were followed from the first day after hatching to the adult stage in two bird species representing different strategies of posthatch development: the nidifugous type (leaving the nest directly post-hatch, e.g. quail) and the nidicolous type (remaining for longer period in the nest, e.g. finch). in the zebra finch, parallel with a striking increase in ganglioside concentration, two main postnatal changes in the ganglioside composition occ ... | 1985 | 3986588 |
| ontogeny of brain nuclei controlling song learning and behavior in zebra finches. | an anatomically discrete system of interconnected brain nuclei controls production of learned song patterns in adult male zebra finches (poephila guttata). the corresponding nuclei in females, who do not sing, are greatly reduced in volume. cells in some telencephalic song-control nuclei accumulate androgens, and male nuclei contain a much higher proportion of hormone-concentrating cells than do female nuclei. the main purpose of this experiment was to examine the normal ontogeny of the total vo ... | 1985 | 4009245 |
| lack of sexual dimorphism in steroid accumulation in vocal control brain regions of duetting song birds. | tritiated testosterone was injected into bay wrens (thryothorus nigricapillus), a neotropical species in which the female sings a complex song in intricately timed vocal duets with males. autoradiographic analysis indicated that male and female wrens have the same proportion of cells labeled by testosterone or its metabolites in two brain regions involved in song: the caudal nucleus of the ventral hyperstriatum (hvc) and the magnocellular nucleus of the anterior neostriatum (man). this contrasts ... | 1985 | 4041866 |
| [a scanning electron microscopical and morphometrical analysis of neuromuscular junctions in different muscle fiber types in the zebra finch and rat]. | the differences of neuromuscular junctions (nmjs) between different muscle fibers had been examined with scanning electron microscopy and analyzed morphometrically. the anterior and posterior latissimus dorsi muscles of the zebra finch were compared. the former consisted exclusively of slow tonic fibers and the latter of fast twitch fibers. the former had numerous, small nmjs. the synaptic depressions were small in number. the latter had a large nmj. the synaptic depressions were large in number ... | 1985 | 4045272 |
| the regional and subcellular development of cholecystokinin immunoreactivity in vertebrate brain. | we have previously demonstrated that the development of cck in rat brain occurs during the first postnatal month. in order to determine whether the appearance of cck is associated with specific aspects of brain histogenesis, we examined the development of brain cck immunoreactivity in both precocial and altricial mammals and birds. the two precocial species (guinea pig and chicken) were found to achieve adult cck concentrations prenatally, while the altricial species (zebra finch and rat) manife ... | 1985 | 4052814 |
| peptidergic pathways in the avian brain. | the results obtained by topographical studies on the immunoreactive peptide systems in the embryonic and adult avian brain (domestic fowl, domestic mallard, pigeon, japanese quail, and zebra finch) can be realized only by means of phylogenetical comparisons. the comparative studies mainly demonstrate a fascinating constancy of the immunological properties and the spatial distribution of the neuropeptides. independent of the development of the neopallium, and the increasing cerebral complexity, t ... | 1984 | 6151578 |
| quantitative densitometry of neurotransmitter receptors. | an autoradiographic procedure is described that allows the quantitative measurement of neurotransmitter receptors by optical density readings. this procedure is a modification of the method of young and kuhar (1979a). frozen brain sections are labeled in vitro with [3h]ligands under conditions that maximize specific binding to neurotransmitter receptors. the labeled sections are then placed against the 3h-sensitive lkb ultrofilm to produce the autoradiograms. these autoradiograms resemble those ... | 1982 | 6276624 |
| the intermediate host spectrum in a sarcocystis species of birds. | the life cycle of an avian sarcocystis has been completed in the laboratory, originating with naturally infected icterids and passing alternately between opossums (didelphis virginiana) and experimentally infected birds. to determine the intermediate host range, six avian species, including canaries (serinus canarius), zebra finches (poephila guttata), budgerigars (melopsittacus undulatus), pigeons (columba livia), chickens (gallus gallus), and guinea fowl (numida meleagris), were inoculated ora ... | 1982 | 6811715 |
| evidence for cholinergic participation in the control of bird song; acetylcholinesterase distribution and muscarinic receptor autoradiography in the zebra finch brain. | brain regions thought to be involved in the control of song in the zebra finch (poephila guttata), were examined histochemically using the karnovsky and roots direct-coloring method for the detection of acetylcholinesterase (ache) and the autoradiographic method for the localization of muscarinic cholinergic receptors following injection of tritiated quinuclidinyl benzilate (3h qnb). all presently identified vocal control nuclei in both males and females contain ache. these nuclei include area x ... | 1981 | 7298898 |
| enkephalin-like immunoreactivity in vocal control regions of the zebra finch brain. | singing in passerine birds is an androgen-dependent behavior typical of males, and in many species is learned during an early critical period. brain regions which control song form a rather discrete, interconnected series of nuclei which have been described in the canary and zebra finch. these regions include the caudal nucleus of the hyperstriatum ventrale (hvc), the robust nucleus of the archistriatum (ra), the magnocellular nucleus of the neostriatum (man), area x of the lobus parolfactorius, ... | 1981 | 7306811 |
| quantitative analysis of sex differences in hormone accumulation in the zebra finch brain: methodological and theoretical issues. | the autoradiographic method was used to compare the numbers of hormone accumulating cells in several brain regions in male and female zebra finches (poephila guttata) after injection of tritiated testosterone. the brain regions examined were the caudal nucleus of the hyperstriatum ventrale (hvc), magnocellular nucleus of the anterior neostriatum (man), robust nucleus of the archistriatum (ra), nucleus intercollicularis of the midbrain (ico), the tracheosyringeal hypoglossal motor nucleus (nxiits ... | 1980 | 7372856 |
| androgen affects cholinergic enzymes in syringeal motor neurons and muscle. | we examined the role of testosterone (t) in regulating the weight of the songbird syrinx and the activity of two cholinergic enzymes, choline acetyltransferase (cat) and acetylcholinesterase (ache). castration of adult male zebra finches or neonatal canaries results in a lowering of syringeal weight and cat and ache activity. administration of t for 1-4 weeks restores syringeal weight and ache to intact levels in male zebra finches. activity of cat in muscle is not fully restored. ovariectomy of ... | 1980 | 7378793 |
| isolation and characterization of a cdna encoding the zebra finch myelin proteolipid protein. | a cdna was isolated from a zebra finch telencephalon cdna library that encodes the myelin proteolipid protein. the clone was 2874 nucleotides long containing an open reading frame of 831 nucleotides that encoded a 277 amino acid myelin proteolipid protein. the 5'- and 3' untranslated regions were 112 and 1931 nucleotides, respectively. in northern blots the clone hybridized to 3 bands of 3.5, 2.4 and 1.5 kb in mouse brain rna, but to only a single band of 3.0 kb in zebra finch brain rna, suggest ... | 1994 | 7528351 |
| convergence of untutored song in group-reared zebra finches (taeniopygia guttata). | zebra finches develop abnormal song if they cannot interact with adult song tutors during the 1st few months after hatching. the authors investigated whether untutored juveniles would learn song from each other. the birds were isolated from adult males at 10 days of age and their songs recorded after day 80. by the authors' measures of syllable sharing and the judgments of human listeners, the songs of untutored brothers were as similar to each other as those of birds reared together with a tuto ... | 1995 | 7554823 |
| song isolation is associated with maintaining high spine frequencies on zebra finch 1man neurons. | male zebra finches normally learn much of their song during the second month after hatching. this is a period of rapid change throughout the brain. we studied anatomical consequences of manipulating exposure to song. we investigated neurons of lateral man (1man), a nucleus implicated in song learning (bottjer et al., 1984), in male and female zebra finches (taeniopygia guttata) at 55 days posthatch. birds were raised either under normal colony conditions (social) or in colonies in which adult ma ... | 1995 | 7582809 |
| immunochemical localization of calcium/calmodulin-dependent protein kinase i. | ca2+/calmodulin-dependent protein kinase i (cam kinase i) was originally identified in rat brain based on its ability to phosphorylate site 1 of synapsin i. recently a cdna for the rat brain enzyme has been cloned and the primary structure elucidated [picciotto et al. (1993), j. biol. chem., 268:26512-26521]. the rat cdna encoded a protein of 374 amino acids with a calculated m(r) of 41,636. antibodies have now been raised against the recombinant kinase expressed in e. coli as a glutathione-s-tr ... | 1995 | 7624832 |
| characterization of a novel protein regulated during the critical period for song learning in the zebra finch. | a male zebra finch learns a song by listening to a tutor, but song learning is normally restricted to a critical period in juvenile development. here we identify an rna whose expression in the song control circuit is altered during this critical period. the rna encodes a soluble presynaptic protein that forms a predicted amphipathic alpha helix typical of the lipid-binding domain in apolipoproteins. we show this protein, which we call synelfin, to be the homolog of the human non-a beta component ... | 1995 | 7646890 |
| discrimination of synthetic full-formant and sinewave/ra-la/continua by budgerigars (melopsittacus undulatus) and zebra finches (taeniopygia guttata). | discrimination of three synthetic versions of a/ra-la/ speech continuum was studied in two species of birds. the stimuli used in these experiments were identical to those used in a previous study of speech perception by humans [best et al., percept. psychophys. 45, 237-250 (1989)]. budgerigars and zebra finches were trained using operant conditioning and tested on three different series of acoustic stimuli: three-formant synthetic speech, sinewave versions of those tokens, and isolated f3 tones ... | 1995 | 7699165 |
| isolation of salmonella typhimurium from zebra finches (poephila guttata). | salmonella typhimurium was isolated from a fresh fecal sample of zebra finches (poephila guttata) in december 1992 on an aviary where a large scale outbreak of s. typhimurium infection among bengalees (a variety of lonchura striata) in 1991 had been recorded. the isolates from zebra finches were examined for antibiotic sensitivity and plasmids, which were 60 mdal, then they showed the same pattern as those of s. typhimurium isolated at the previous outbreak. this is the first report of s. typhim ... | 1995 | 7756407 |
| localization of met-enkephalin and vasoactive intestinal polypeptide in the brains of male zebra finches. | an interconnected series of brain nuclei controls song learning and behavior in male zebra finches (poephila guttata). this study examined the distribution of fibers, terminals, and somata immunoreactive for two neuropeptides, methionine-enkephalin (enk) and vasoactive intestinal polypeptide (vip), in song-control nuclei of adult males. in addition, the broad pattern of major regions of labeling throughout the forebrain and midbrain was determined. the telencephalic song-control nuclei man (magn ... | 1995 | 7796094 |
| two separate areas of the brain differentially guide the development of a song control nucleus in the zebra finch. | a brain nucleus that is important for the generation of song in the adult male zebra finch (poephila guttata), the robust nucleus of the archistriatum (ra), receives dual inputs from two other telencephalic song nuclei: the hyperstriatum ventrale pars caudale (hvc) and the lateral magnocellular nucleus of the anterior neostriatum (l-man). we lesioned each of these afferent inputs to the ra early in development, either by themselves or both at the same time in the same side of the brain, to deter ... | 1994 | 7809051 |
| flavobacterium meningosepticum, a pathogen in birds. | five bacterial isolates were recovered from various diseased birds (chickens, a pigeon, and a zebra finch) and were identified as flavobacterium meningosepticum. four of them were isolated in pure or nearly pure culture of samples from internal organs, and one strain was isolated in mixed culture of a tarsal joint fluid sample. except for the last case, there was no evidence of other disease agents. by using phenotypic, chemotaxonomic, and genomic methods, the strains were taxonomically characte ... | 1994 | 7814473 |
| distribution of gaba-like immunoreactivity in the song system of the zebra finch. | gaba-like immunoreactivity (gaba-lir) was mapped in the male and female zebra finch song system using a polyclonal antibody to gaba. gaba-lir was found throughout the song system in neurons and neuropil of the robust nucleus of the archistriatum (ra), the higher vocal center (hvc), area x, the magnocellular nucleus of the neostriatum (man), and the dorsomedial portion of the nucleus intercollicularis (dm of ico). puncta present in the lateral division of man (lman) may be local interneurons sinc ... | 1994 | 7922557 |
| waiting periods versus early innervation: the development of axonal connections in the zebra finch song system. | this study examines the development of two neural pathways within the zebra finch forebrain that function respectively in the juvenile acquisition and the adult production of learned song. in the adult male zebra finch forebrain, the song nuclei l-man and hvc both innervate nucleus ra; l-man plays a crucial role in juvenile song acquisition but, unlike hvc and ra, is not essential for adult song production. previous studies have shown that hvc axons arrive at the dorsal border of ra as early as ... | 1994 | 7965057 |
| isolation and characterization of a zebra finch aromatase cdna: in situ hybridization reveals high aromatase expression in brain. | the brain regions controlling song are much larger in male than in female zebra finches. this sex difference is thought to arise developmentally when the male's brain is exposed to higher levels of estrogen. the synthesis of estrogen from androgen is catalyzed by aromatase, a key enzyme implicated in song development in the zebra finch. to study the role of estrogen synthesis in the organization of brain regions responsible for song, a cdna encoding aromatase was isolated from a zebra finch ovar ... | 1994 | 7968362 |
| expression of a specific marker of avian programmed cell death in both apoptosis and necrosis. | apoptosis and necrosis are two types of cell death with different morphologic features. we report here the isolation of a monoclonal antibody, bv2, that specifically recognizes cells undergoing developmental programmed cell death in different tissues of the chicken and zebra-finch embryos. the antigen recognized by bv2 monoclonal antibody is detected in vitro in primary chicken embryonic fibroblasts induced to die by actinomycin d, as well as fibroblasts induced to die by chemical anoxia. the ex ... | 1994 | 8078937 |
| selection and utilization of spermatozoa in the reproductive tract of the female zebra finch taeniopygia guttata. | the numbers and proportion of spermatozoa reaching different parts of the female reproductive tract after a single natural insemination were investigated in zebra finches taeniopygia guttata. the number of spermatozoa transferred during a single, natural copulation was estimated by comparing the number of spermatozoa in the seminal glomera of males that had performed a single copulation with control males. the mean number of spermatozoa per ejaculate was 5.8 x 10(6) +/- 1.80 x 10(6) sem. the mea ... | 1993 | 8107044 |
| sexual differentiation of brain and behavior: the zebra finch is not just a flying rat. | in rats and other mammals, sex differences in the brain and behavior result from differential secretions of gonadal steroid hormones during early critical periods of neural development. we review the experimental results that support current ideas about the mechanisms of sexual differentiation in mammals, and then apply the same experimental analysis to the study of sexual differentiation of the neural song circuit in the zebra finch (poephila guttata), a passerine song bird. administration of e ... | 1993 | 8252375 |
| yolk is a source of maternal testosterone for developing birds. | the sex steroid hormones that affect development in birds have been thought to be produced exclusively by the embryo or neonate. i used radioimmunoassay to measure the amounts of androstenedione, 5 alpha-dihydrotestosterone, testosterone, 17 beta-estradiol, and corticosterone in the yolk of freshly laid canary (serinus canaria) and zebra finch (poephila guttata) eggs. testosterone was found in both canary and zebra finch eggs, but its contents were much higher in the former than in the latter. t ... | 1993 | 8265571 |
| mycobacteriosis due to mycobacterium genavense in six pet birds. | six cases of mycobacteriosis due to mycobacterium genavense in three budgerigars (melopsittacus undulatus), one orange-winged amazon (amazona amazonica), one flycatcher (cyanoptila cyanomelana), and one zebra finch (taeniopygia guttata) are discussed. gross lesions associated with the infection included a high degree of muscular wasting (five cases), hepatomegaly (four cases), and thickening of the wall of the small intestine (four cases). granulomas were found in the lung (one case) and the sub ... | 1993 | 8463407 |
| ultrastructural organization of avian stratum corneum lipids as the basis for facultative cutaneous waterproofing. | the ultrastructure of naked neck epidermis from the ostrich (struthio camelus) and ventral apterium from watered, and water-deprived, zebra finches (taeniopygia [poephila] guttata castanotis) is presented. the form and distribution of the fully differentiated products of the lipid-enriched multigranular bodies are compared in biopsies post-fixed with osmium tetroxide or ruthenium tetroxide. the fine structure of ostrich epidermis suggests it is a relatively poor barrier to cutaneous water loss ( ... | 1996 | 8568904 |
| a large-capacity memory system that recognizes the calls and songs of individual birds. | auditory responses in the caudomedial neostriatum (ncm) of the zebra finch (taeniopygia guttata) forebrain habituate to repeated presentations of a novel conspecific song. this habituation is long lasting and specific to individual stimuli. we here test the acoustic and ethological basis of this stimulus-specific habituation by recording extracellular multiunit activity in the ncm of awake male and female zebra finches presented with a variety of conspecific and heterospecific vocalizations, whi ... | 1996 | 8700865 |
| identification, distribution, and developmental changes of a melatonin binding site in the song control system of the zebra finch. | in many avian species, singing is a circadian or seasonal behavior that appears to be widely dependent on gonadal steroid hormones. to explore the possibility of a further hormone-dependent vocal control mechanism driven by the action of melatonin, we examined the binding of iodinated melatonin (imel) in the vocal control network of adult and juvenile (22- and 40-day-old) zebra finches. imel binding areas of the zebra finch brain were localized and characterized by using quantitative in vitro au ... | 1996 | 8708012 |
| organization of afferent and efferent projections of the nucleus basalis prosencephali in a passerine, taeniopygia guttata. | the connections of nucleus basalis (nb) of the rostral forebrain of the zebra finch were investigated electrophysiologically and with anterograde and retrograde tracing methods to determine their functional organization, the sources of their pontine afferents, and the targets of their telencephalic efferents. the nucleus was found to be partitioned into three major components, a rostral lingual part that received a hypoglossal projection via a lateral subnucleus of the principal sensory trigemin ... | 1996 | 8822172 |
| distribution of aromatase-immunoreactive cells in the forebrain of zebra finches (taeniopygia guttata): implications for the neural action of steroids and nuclear definition in the avian hypothalamus. | cells immunoreactive for the enzyme aromatase were localized in the forebrain of male zebra finches with the use of an immunocytochemistry procedure. two polyclonal antibodies, one directed against human placental aromatase and the other directed against quail recombinant aromatase, revealed a heterogeneous distribution of the enzyme in the telencephalon, diencephalon, and mesencephalon. staining was enhanced in some birds by the administration of the nonsteroidal aromatase inhibitor, r76713 rac ... | 1996 | 8885196 |
| infectivity and persistence of salmonella typhimurium for zebra finches (poephila guttata) isolated from the same species. | salmonella typhimurium (s. typhimurium) originating from a naturally infected zebra finch (poephila guttata), a common cage bird, was examined for the infectivity to the same species of the birds because of its importance to public health. eight birds per group for each experiment were used. when zebra finches were inoculated orally with 10(2), 10(4) or 10(5) colony forming units (cfu) of s. typhimurium and observed for 7 days, all the birds receiving 10(5) cfu of s. typhimurium were positive fo ... | 1996 | 8898281 |
| blockade of nmda receptors in the anterior forebrain impairs sensory acquisition in the zebra finch (poephila guttata). | juvenile zebra finches (poephila guttata) learn song in two stages: during sensory acquisition, they memorize the song of an adult tutor, and during sensorimotor learning, they alter their vocalizations to match the stored song model. like many other forms of neural plasticity and memory formation, vocal learning in zebra finches is impaired by pharmacological blockade of nmda receptors, but the relevant nmda receptors have not yet been localized. during song development, one neural region that ... | 1996 | 8946423 |
| projections of the dorsomedial nucleus of the intercollicular complex (dm) in relation to respiratory-vocal nuclei in the brainstem of pigeon (columba livia) and zebra finch (taeniopygia guttata). | injections of neuronal tracers were made into the dorsomedial nucleus of the intercollicular complex (dm) of pigeons and zebra finches in order to investigate the projections of this nucleus which has long been implicated in respiratory-vocal control. despite the fact that pigeons are nonsongbirds and zebra finches are songbirds, the projections were very similar in both species. most descended throughout the brainstem, taking ventral and dorsal trajectories, which merged in the medulla. those d ... | 1997 | 8989654 |
| zebra finch estrogen receptor cdna: cloning and mrna expression. | in zebra finches, estrogen is a potent hormone that masculinizes the neural circuitry controlling song during development and activates song in adulthood. however, previous studies have reported conflicting patterns of estrogen receptor (er) expression in the song control regions. to obtain additional information about the distribution of er in the zebra finch brain, a cdna encoding an estrogen receptor was isolated from a zebra finch hypothalamic-preoptic area cdna library. the 2792 bp insert c ... | 1996 | 9010328 |
| intracerebral sex differences in the vasotocin system in birds: possible implication in behavioral and autonomic functions. | the brain vasotocinergic system demonstrates clear sexual dimorphism in birds investigated so far. this paper examines the evidence obtained in studies on gallinaceous (domestic fowl, japanese quail) and passerine (canary, junco, zebra finch) birds. vasotocin (vt)-immunoreactive parvocellular neurons are present in the nucleus of stria terminalis of males, but they are less abundant or absent in the corresponding structure of females. a similar difference has been observed in the dorsal paravent ... | 1996 | 9047289 |
| estrogen synthesis and secretion in the brown-headed cowbird (molothrus ater). | estrogens exert profound effects on vertebrate physiology and behavior. in most vertebrates, including birds, estrogens derived from ovarian tissue circulate at high levels during discrete periods of reproductive activity, and estrogen levels in males are low. in some songbirds (passeriformes) plasma estrogens are high in both males and females. in the zebra finch, aromatase (estrogen-synthetase) is expressed abundantly in several regions of the male and female telencephalon and contributes to p ... | 1997 | 9073501 |
| a putative 5 alpha-reductase inhibitor demasculinizes portions of the zebra finch song system. | one model of the sexual differentiation of the zebra finch song system holds that both major metabolites of testosterone, dihydrotestosterone (dht) and estradiol (e2), act together to masculinize the song system. to test this model, we administered a putative inhibitor of 5 alpha-reductase (mk-434) to decrease the synthesis of dht from testosterone (t) in hatchling zebra finches. we tested mk-434's inhibition of 5 alpha-reductase, 5 beta-reductase, and aromatase in vivo and in vitro. in vivo, mk ... | 1997 | 9098536 |
| reafferent thalamo- "cortical" loops in the song system of oscine songbirds. | songbirds have a complex vocal repertoire, much of which is learned by imitation. the vocal motor system of songbirds includes a set of telencephalic pathways dedicated to the acquisition and production of learned song. the main vocal motor pathway goes from the high vocal center (hvc) to the robust nucleus of the archistriatum (ra), which in turn innervates mesencephalic and medullary nuclei involved in vocalization. we used neural tract tracers (biotinylated dextran amines, fluorescein- and rh ... | 1997 | 9100137 |
| motor-driven gene expression. | there is increased neuronal firing in the high vocal center (a motor nucleus) and other song nuclei of canaries, serinus canaria, and zebra finches, taeniopygia guttata, whenever these songbirds sing or hear song. these observations suggested that song perception involved sensory and motor pathways. we now show that the act of singing, but not hearing song, induces a rapid and striking increase (up to 60-fold) in expression of the transcriptional regulator zenk in the high vocal center and other ... | 1997 | 9108111 |
| selective expression of insulin-like growth factor ii in the songbird brain. | neuronal replacement occurs in the forebrain of juvenile and adult songbirds. to address the molecular processes that govern this replacement, we cloned the zebra finch insulin-like growth factor ii (igf-ii) cdna, a factor known to regulate neuronal development and survival in other systems, and examined its expression pattern by in situ hybridization and immunocytochemistry in juvenile and adult songbird brains. the highest levels of igf-ii mrna expression occurred in three nuclei of the song s ... | 1997 | 9278533 |
| cochlosoma infections in finches. | to survey finches in pet shops for cochlosoma infection and evaluate the efficacy of antiprotozoal therapy with metronidazole or ronidazole. | 1997 | 9293335 |
| sex differences in neuropeptide staining of song-control nuclei in zebra finch brains. | this study examined the distribution of the neuropeptides somatostatin (ss) and calcitonin gene-related peptide (cgrp) in forebrain and midbrain song-control nuclei of male versus female brains in adult zebra finches (poephila guttata) using immunohistochemical techniques. vocal learning in songbirds is controlled by an interconnected, highly-localized system of brain nuclei. male zebra finches produce learned vocalizations, and females do not. this behavioral sexual dimorphism is reflected in a ... | 1997 | 9360005 |
| distribution and dynamics in the expression of androgen and estrogen receptors in vocal control systems of songbirds. | developmental and seasonal changes in the production of androgens and estrogens seem to control sex-specific differentiation and seasonal changes in sexual behaviors such as singing of songbirds. these steroids affect the brain by binding to intracellular located receptors. here we analyze whether the expression of androgen receptors (ar) and estrogen receptors (er) is a limiting factor for differentiation of the vocal pattern and the vocal control system of zebra finches and canaries. ar and er ... | 1997 | 9370218 |
| synelfin regulation during the critical period for song learning in normal and isolated juvenile zebra finches. | male zebra finches (taeniopygia guttata) learn to sing during a critical period in adolescence. we previously described a presynaptic protein, synelfin, whose mrna is increased early in this critical period in a brain nucleus specifically implicated in song learning, lateral man (lman). in the current study, in situ hybridization was used to map this change in gene expression to the subregion of lman that projects to the robust nucleus of the archistriatum (ra), the principal motor output of the ... | 1997 | 9398589 |
| detection of changes in timbre and harmonicity in complex sounds by zebra finches (taeniopygia guttata) and budgerigars (melopsittacus undulatus). | thresholds for detecting alterations in the timbre and harmonicity of complex harmonic signals were measured in zebra finches, budgerigars, and humans. the stimuli used in this experiment were designed to have particular salience for zebra finches by modeling them after natural zebra finch calls. all 3 species showed similar abilities for detecting an amplitude decrement in a single component of a harmonic complex. however, zebra finches and budgerigars were extraordinarily sensitive to the mist ... | 1998 | 9528113 |
| temporal and spectral sensitivity of complex auditory neurons in the nucleus hvc of male zebra finches. | complex vocalizations, such as human speech and birdsong, are characterized by their elaborate spectral and temporal structure. because auditory neurons of the zebra finch forebrain nucleus hvc respond extremely selectively to a particular complex sound, the bird's own song (bos), we analyzed the spectral and temporal requirements of these neurons by measuring their responses to systematically degraded versions of the bos. these synthetic songs were based exclusively on the set of amplitude enve ... | 1998 | 9570809 |
| visual pigments and oil droplets from six classes of photoreceptor in the retinas of birds. | microspectrophotometric examination of the retinal photoreceptors of the budgerigar (shell parakeet), melopsittacus undulatus (psittaciformes) and the zebra finch, taeniopygia guttata (passeriformes), demonstrate the presence of four, spectrally distinct classes of single cone that contain visual pigments absorbing maximally at about 565, 507, 430-445 and 360-380 nm. the three longer-wave cone classes contain coloured oil droplets acting as long pass filters with cut-offs at about 570, 500-520 a ... | 1997 | 9578901 |
| existence and localization of a protein in zebra finch brain with similar structural features as the large subunit of the splicing factor u2af. | from brains of the adult male zebra finch, we purified a peptide that has a homologous sequence of the large subunit of human u2af. u2af is a non-small-nuclear ribonucleoprotein (snrnp) splicing factor required for pre-spliceosome assembly. u2af consists of a large and a small subunit, whereas only a large subunit is required for in vitro splicing. to show that u2af large-subunit-like protein exists in the brain of zebra finches, we conducted immunoblot analysis on brain extract, using antiserum ... | 1998 | 9597763 |
| frequency-range discriminations: special and general abilities in zebra finches (taeniopygia guttata) and humans (homo sapiens). | the acoustic frequency ranges in birdsongs and human speech can provide important pitch cues for recognition. zebra finches and humans were trained to sort contiguous frequencies into 3 or 8 ranges, based on associations between the ranges and reward. the 3-range task was conducted separately in 3 spectral regions. zebra finches discriminated 3 ranges in the medium and high spectral regions faster than in the low region and discriminated 8 ranges with precision. humans discriminated 3 ranges in ... | 1998 | 9770314 |
| multiple cell types distinguished by physiological, pharmacological, and anatomic properties in nucleus hvc of the adult zebra finch. | nucleus hvc of the songbird is a distinct forebrain region that is essential for song production and shows selective responses to complex auditory stimuli. two neuronal populations within hvc give rise to its efferent projections. one projection, to the robust nucleus of the archistriatum (ra), serves as the primary motor pathway for song production, and can also carry auditory information to ra. the other projection of hvc begins a pathway through the anterior forebrain, (area x --> medial port ... | 1998 | 9772242 |
| neural bases of song preferences in female zebra finches (taeniopygia guttata). | we examined the neural bases of song preferences in female zebra finches (taeniopygia guttata). females performed more courtship displays in response to conspecific songs than to heterospecific songs. following electrolytic lesion to the hvc (sometimes referred to as high vocal center), females maintained normal song preferences. however, following lesion to chv (caudal hyperstriatum ventrale, an auditory area) females performed courtship displays at high rates in response to both conspecific an ... | 1998 | 9804314 |
| the comparative nutrition of two passerine species: the canary (serinus canarius) and the zebra finch (poephila guttata). | | 1998 | 9868241 |
| sperm transport in the reproductive tract of female zebra finches (taeniopygia guttata). | aspects of sperm transport in the oviducts of female zebra finches were examined by recording the decline in the number of spermatozoa on the outer perivitelline layer of successively laid eggs. data from a single clutch of eggs from 32 females indicates that the mean per capita rate of loss of spermatozoa was estimated to be 0.0170 +/- 0.002 sem spermatozoa h-1. however, individual females showed no consistency in the rate at which spermatozoa were lost from their oviduct over five successive c ... | 1998 | 9875166 |
| distribution of aromatase, estrogen receptor, and androgen receptor mrna in the forebrain of songbirds and nonsongbirds. | androgens and estrogens are crucial for the differentiation and function of the vocal control system of songbirds. a major source of estrogens in songbirds is the cerebral aromatization of circulating testosterone by aromatase (aro). in the vocal control system, songbirds have a unique estrogen receptor (er)-containing area, the nucleus hyperstriatalis ventrale pars caudale (hvc) of the caudal neostriatum. work in the zebra finch has demonstrated aro expression adjacent to but not in the hvc. co ... | 1999 | 10213192 |
| avian species differences in susceptibility to noise exposure. | previous studies of hair cell regeneration and hearing recovery in birds after acoustic overstimulation have involved relatively few species. studies of the effects of acoustic overexposure typically report high variability. though it is impossible to tell, the data so far also suggest there may be considerable species differences in the degree of damage and the time course and extent of recovery. to examine this issue, we exposed four species of birds (quail, budgerigars, canaries, and zebra fi ... | 1999 | 10355606 |
| validation of immunotoxicology techniques in passerine chicks exposed to oil sands tailings water. | avian species, through their trophic relationships, may represent ideal indicators for assessing environmental health. in this study several assays of immune function in young passerines are validated and compared. from 6 to 10 days of age, zebra finch nestlings (taeniopygia guttata) were given daily oral doses of oil sands tailings water (ct), an immunosuppressant dexamethasone, or phosphate-buffered saline. at 9-10 days of age, a phytohemagglutinin (pha) skin test of immune function was conduc ... | 1999 | 10499996 |
| zebra finch aromatase gene expression is regulated in the brain through an alternate promoter. | the learned singing behavior in songbirds is sex-steroid-dependent and sexually dimorphic. estrogen plays a major role in masculinizing the song system in these songbirds. the songbird brain synthesizes large amounts of estrogen, which, in the case of zebra finches, have been found to enter the systemic circulation. aromatase cytochrome p450 is the key enzyme catalyzing the conversion of androgens to estrogens. we have cloned a novel alternatively spliced form of aromatase cdna expressed predomi ... | 1999 | 10564828 |
| effect of testosterone on the distribution of vasotocin immunoreactivity in the brain of the zebra finch, taeniopygia guttata castanotis. | the distribution of vasopressin or vasotocin immunoreactive cells and fibers in the lateral septum and the bed nucleus of the stria terminalis are sexually dimorphic in many vertebrates including several species of birds examined to date. we examined the vasotocin-like immunoreactivity in the zebra finch brain. male birds had a higher level of immunoreactive staining in some telencephalic and diencephalic regions. the density of immunostaining increased in the testosterone-treated females to lev ... | 1999 | 10573184 |
| experimental inoculation of domestic pigeons (columbia livia) and zebra finches (poephila guttata) with neospora caninum tachyzoites. | dogs are a definitive host of neospora caninum and cattle are intermediate hosts. alternative life-cycles have not been investigated. foxes are frequently seropositive, but may not commonly prey upon cattle; therefore, other intermediate hosts may exist that are frequent prey of foxes. three domestic pigeons (columbia livia) and three zebra finches (poephila guttata) were inoculated with n. caninum tachyzoites, to determine if they could serve as intermediate hosts. tissue culture, pcr, serology ... | 1999 | 10608438 |
| a simple and sensitive antigen retrieval method for free-floating and slide-mounted tissue sections. | the masking of antigens by aldehyde-containing fixatives or by paraffin embedding procedures is a problem for immunohistochemical studies. enzymatic digestion, formic acid treatment, microwave heating and autoclave heating have been used to deal with this problem, with microwave heating-based antigen retrieval having become widely used as the method of choice. microwave heating, however, has the shortcoming that it is difficult to precisely control the heating temperature and it is difficult to ... | 1999 | 10634500 |
| a panel of epitope-specific antibodies detects protein domains distributed throughout human alpha-synuclein in lewy bodies of parkinson's disease. | to facilitate studies of the normal biology of alpha-synuclein, a member of a family of neuronal proteins of unknown function, and to elucidate the role of alpha-synuclein pathologies in neurodegenerative diseases, we generated and characterized a panel of anti-synuclein antibodies. here we demonstrate that these antibodies recognize defined epitopes spanning the entire length of human alpha-synuclein, and that some of these antibodies also cross-react with zebra finch and rodent synucleins. sin ... | 2000 | 10679792 |
| the differential roles of right and left sides of the brain in memory formation. | a series of transitions in chick memory formation, with sharp standard timings, which were revealed by amnestic agents, coincide with a series of brief windows of enhanced recall ('retrieval events'), repeating with periods of 16 min (left hemisphere) and 25 min (right). their timings were recently confirmed by: (1) the demonstration of a brief dip in recall 5 min after each left hemisphere event in the period 0-100 min, (2) spontaneous use of the eye providing direct input to the hemisphere und ... | 1999 | 10683118 |
| photoperiodic regulation of the reproductive axis in male zebra finches, taeniopygia guttata. | in arid central australia, breeding of zebra finches (taeniopygia guttata) tends to take place immediately after the aperiodic rainfall-this being irrespective of the time of year. as a result, zebra finches have traditionally been considered nonphotoperiodic. despite this, there are some published reports of photoperiodic effects on behavior in zebra finches. therefore, we transferred singly housed male zebra finches from a photoperiod of 14 h light and 10 h dark per day (14l:10d) to either 20l ... | 2000 | 10764555 |
| fiber diffraction of synthetic alpha-synuclein filaments shows amyloid-like cross-beta conformation. | filamentous inclusions made of alpha-synuclein constitute the defining neuropathological characteristic of parkinson's disease, dementia with lewy bodies, and multiple system atrophy. rare familial cases of parkinson's disease are associated with mutations a53t and a30p in alpha-synuclein. we report here the assembly properties and secondary structure characteristics of recombinant alpha-synuclein. carboxy-terminally truncated human alpha-synuclein (1-87) and (1-120) showed the fastest rates of ... | 2000 | 10781096 |