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1.
Neurosci Lett ; 396(2): 108-12, 2006 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-16377089

RESUMO

Auditory-visual cross-modal innervation was examined in control (sighted, ZRDCT-N) and congenitally anophthalmic (eyeless, ZRDCT-AN) mice using electrophysiological recording and pathway tracing with carbocyanine dyes. Electrophysiological data demonstrate that the primary visual cortex of congenitally eyeless, blind, mice receives auditory stimuli. Neuroanatomical data demonstrate a direct connection between the inferior colliculus (IC) and visual cortex. Our experiments provide new information about how the brain adapts to the loss of sight.


Assuntos
Anoftalmia/patologia , Anoftalmia/fisiopatologia , Vias Auditivas/patologia , Vias Auditivas/fisiopatologia , Plasticidade Neuronal , Córtex Visual/patologia , Córtex Visual/fisiopatologia , Adaptação Fisiológica , Animais , Córtex Auditivo/patologia , Córtex Auditivo/fisiopatologia , Potenciais Evocados Auditivos , Potenciais Evocados Visuais , Colículos Inferiores/patologia , Colículos Inferiores/fisiopatologia , Camundongos
2.
Brain Res ; 953(1-2): 73-81, 2002 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-12384240

RESUMO

Congenitally anophthalmic mice (ZRDCT-AN) have circadian rhythms which 'free-run' and are not light modulated. Their rhythms differ from those of controls in: duration of circadian period, length of active phase, and pattern/intensity of activity. Three different populations have been described based upon wheel-running: rhythmic with stable period, rhythmic with unstable period and arrhythmic. Circadian rhythms are generated by neurons in the suprachiasmatic nuclei (SCN) of the hypothalamus. To better understand whether intrinsic properties of SCN neurons differ in anophthalmic and sighted mice, we examined the electrical activity of these neurons in slices, using single unit recordings, ionophoresis and bath perfusion of agonists and antagonists of known SCN neurotransmitters. Lucifer yellow was injected to characterize morphology. In controls, in daytime, units fired at a higher rate (44% at >/=5 Hz) than at night (21% at >/=5 Hz) and with regular interspike intervals versus irregular intervals nocturnally. In anophthalmics four firing patterns were observed as follows: (1) irregular at <5 spikes/s (70% of the total); (2) regular at >/=5 spikes/s; (<10%); (3) irregular bursts (20%); (4) regular bursts (<1%). Most neurons were inhibited by GABA, but a few were excited in controls. Blocking synaptic transmission with low Ca(2+)/high Mg(2+) increased the frequency and regularized the pattern of previously irregular discharges both in anophthalmics and controls. Bicuculline (10(-5) M), a GABA(A) antagonist, had a similar effect. These data suggest that the characteristic irregular firing pattern of anophthalmics, and of controls at night, results from extrinsic, at least in part, GABAergic input.


Assuntos
Anoftalmia/patologia , Anoftalmia/fisiopatologia , Núcleo Supraquiasmático/patologia , Núcleo Supraquiasmático/fisiopatologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Anoftalmia/genética , Bicuculina/farmacologia , Cegueira/genética , Cegueira/patologia , Cegueira/fisiopatologia , Cálcio/farmacologia , Ritmo Circadiano/fisiologia , Eletrofisiologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas GABAérgicos/farmacologia , Magnésio/farmacologia , Camundongos , Camundongos Mutantes , N-Metilaspartato/farmacologia , Técnicas de Cultura de Órgãos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia , Ácido gama-Aminobutírico/farmacologia
3.
Genesis ; 31(1): 43-53, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11668677

RESUMO

The eyeless inbred mouse strain ZRDCT has long served as a spontaneous model for human anophthalmia and the evolutionary reduction of eyes that has occurred in some naturally blind mammals. ZRDCT mice have orbits but lack eyes and optic tracts and have hypothalamic abnormalities. Segregation data suggest that a small number of interacting genes are responsible, including at least one major recessive locus, ey1. Although predicted since the 1940s, these loci were never identified. We mapped ey1 to chromosome 18 using an F2 genome scan and there found a Met10-->Leu mutation in Rx/rax, a homeobox gene that is expressed in the anterior headfold, developing retina, pineal, and hypothalamus and is translated via a leaky scanning mechanism. The mutation affects a conserved AUG codon that functions as an alternative translation initiation site and consequently reduces the abundance of Rx protein. In contrast to a targeted Rx null allele, which causes anophthalmia, central nervous system defects, and neonatal death, the hypomorphic M10L allele is fully viable.


Assuntos
Processamento Alternativo/genética , Códon de Iniciação/genética , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila , Proteínas do Olho/genética , Proteínas de Homeodomínio/genética , Mutação , Fatores de Transcrição , Sequência de Aminoácidos , Animais , Sequência de Bases , Olho/embriologia , Feminino , Genótipo , Hibridização In Situ , Masculino , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Xenopus laevis
4.
Brain Res ; 917(1): 105-11, 2001 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-11602234

RESUMO

To date, the search for the clock component that is both necessary and sufficient for generation of circadian rhythms has relied primarily on experimental interventions such as lesions and transplantation of fetal SCN. While these approaches have been fruitful, lesions disrupt adjacent host tissue and fiber pathways, and donor tissue is likewise subject to trauma during harvest and transplantation. The current investigation has used congenitally anophthalmic (eyeless) mice to ask whether VIP-IR SCN neurons are necessary and sufficient for generation of circadian rhythms. In this animal model, arrhythmic mice occur naturally, together with their rhythmic littermates. We have combined recording of wheel-running activity with light microscopic immunocytochemistry for vasoactive intestinal polypeptide (VIP) and cytoarchitectural analysis of the suprachiasmatic nuclei (SCN) in rhythmic and arrhythmic anophthalmic mice. Our data provide the first definitive evidence that the presence of VIP neurons in the SCN is not sufficient for generation of circadian locomotor rhythms.


Assuntos
Anoftalmia/fisiopatologia , Ritmo Circadiano , Núcleo Supraquiasmático/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo , Animais , Imuno-Histoquímica , Camundongos , Atividade Motora , Neurônios/fisiologia , Núcleo Supraquiasmático/citologia
5.
Physiol Behav ; 66(3): 461-71, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10357435

RESUMO

Although it is more common to study the effects of light on circadian systems, nonphotic stimuli can also influence and entrain circadian clocks. Because anophthalmic mice (ZRDCT-AN) have a genetic mutation that prevents the development of the eyes, they do not respond to light or entrain to light-dark cycles. Thus, entrainment of anophthalmic mice requires a nonphotic zeitgeber (entraining stimulus). In the current study we attempted to entrain sighted and anophthalmic mice of the same strain, using restricted access to an unlocked running wheel as the zeitgeber. First, free-running rhythms were established. The running wheels were then locked, and unlocked only from 0930-1130 h each day. Finally, a postentrainment free run was measured. In one group of animals, body temperature and general activity were measured using a Minimitter telemetry system. In another, general activity was measured by a sensitive force plate beneath the cage. Running-wheel activity was recorded in both groups. The force plate proved satisfactory for observing the behavior of the circadian system during wheel locking, and preferable to the temperature transmitters for long-term studies because the battery life of the mouse temperature transmitters was limited. Both sighted and anophthalmic mice were able to entrain to restricted wheel access, although not all animals responded. Mice that did not entrain showed either no effect of wheel locking or exhibited masking.


Assuntos
Anoftalmia/fisiopatologia , Temperatura Corporal/fisiologia , Ritmo Circadiano/fisiologia , Sinais (Psicologia) , Meio Ambiente , Atividade Motora/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos , Fatores de Tempo
6.
Brain Res Dev Brain Res ; 112(1): 129-33, 1999 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-9974166

RESUMO

Development of the eye requires complex interactions between tissues, extracellular matrix and growth factors. Most cells of the optic primordia grow and differentiate into discrete ocular structures; however, other cells have death as their developmental fate. The most common mechanisms of cell death are apoptosis and necrosis. We have identified the cell death that occurs during ocular morphogenesis in ZRDCT-N mice as apoptosis. Mouse embryos, ages E8.5-E11.5, were embedded in paraffin, sectioned at 5 microns and stained with hematoxylin or by the terminal deoxytransferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. The spatial and temporal distribution of apoptotic cells was mapped at 0.5 day intervals using a computerized image analysis system, and 3-D reconstructions were made at each embryonic age. Our data indicate that apoptosis plays a role in normal ocular morphogenesis and provides the groundwork for studies of abnormal ocular development.


Assuntos
Apoptose/fisiologia , Olho/embriologia , Animais , Embrião de Mamíferos/citologia , Embrião de Mamíferos/fisiologia , Desenvolvimento Embrionário e Fetal/fisiologia , Olho/citologia , Processamento de Imagem Assistida por Computador , Marcação In Situ das Extremidades Cortadas , Camundongos/embriologia , Camundongos Endogâmicos C57BL
7.
Physiol Behav ; 64(2): 165-71, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9662081

RESUMO

Circadian rhythms are generated by the suprachiasmatic nuclei (SCN) and synchronized (entrained) to environmental light-dark cycles by the retinohypothalamic tract (RHT), a direct pathway from the retina to the suprachiasmatic nuclei. In anophthalmic mice, the optic primordia are resorbed between embryonic days 11.5 and 13, before retinal ganglion cells emerge. Thus the retinohypothalamic tract, which is the primary "zeitgeber" for circadian rhythms in sighted animals, never forms, and there is no retinal or photic input to the circadian system. We have used wheel running activity, a highly consistent and reliable measure of circadian rhythmicity in rodents, to establish the properties of endogenous locomotor rhythms of anophthalmic mice. We have identified three subpopulations of anophthalmic mice: a) rhythmic with strong stable circadian period but significantly increased period length; b) rhythmic with unstable circadian period; and c) arrhythmic. Future correlation of locomotor rhythms with properties of the suprachiasmatic nuclei in these mice will clarify the relationship between generation and properties of circadian rhythms and the neuroanatomical, neurochemical, and molecular organization of the circadian clock.


Assuntos
Cegueira/genética , Cegueira/psicologia , Anormalidades do Olho/genética , Anormalidades do Olho/psicologia , Atividade Motora/genética , Atividade Motora/fisiologia , Animais , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Hipotálamo/anormalidades , Hipotálamo/fisiologia , Masculino , Camundongos , Vias Neurais/anormalidades , Vias Neurais/fisiologia , Retina/anormalidades , Retina/fisiologia
8.
Brain Res ; 688(1-2): 203-8, 1995 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-8542309

RESUMO

The present study has combined recording of circadian locomotor rhythms with light microscopic immunocytochemistry for vasoactive intestinal polypeptide (VIP) in the suprachiasmatic nucleus (SCN) of congenitally anophthalmic mice. These mice, which never develop retinae or optic nerves and do not perceive light, are thus in constant darkness. Our data show a circadian rhythm in expression of VIP in the SCN of anophthalmic mice--expression is maximal during late subjective night/early subjective day and minimal in late subjective day/early subjective night. These observations support the hypothesis that expression of VIP is related to regulation of circadian rhythms by the SCN.


Assuntos
Anoftalmia/metabolismo , Ritmo Circadiano/fisiologia , Núcleo Supraquiasmático/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo , Animais , Imuno-Histoquímica , Masculino , Camundongos
9.
Brain Res ; 618(2): 352-7, 1993 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-8374768

RESUMO

In a previous study we described abnormalities in cytoarchitecture and vasoactive intestinal polypeptide distribution in the suprachiasmatic nucleus (SCN) of anophthalmic mice. However, the effect of anophthalmia on the geniculohypothalamic pathway, an important pathway for relay of photic information to the SCN, is not known. The present study examined the geniculohypothalamic pathway in congenitally anophthalmic and sighted control mice. The data demonstrate that the development of an intergeniculate leaflet (IGL), the expression of neuropeptide Y (NPY) by IGL neurons and the formation of NPY terminal fields in the SCN proceed in the absence of retinal input. Although the cytoarchitectural organization of the anophthalmic IGL differs from that of the control mouse, the distribution of NPY plexuses in the suprachiasmatic nucleus is remarkably similar.


Assuntos
Anoftalmia/patologia , Corpos Geniculados/patologia , Hipotálamo/patologia , Animais , Benzoxazinas , Histocitoquímica , Camundongos , Camundongos Endogâmicos , Vias Neurais/patologia , Neuropeptídeo Y/metabolismo , Oxazinas , Retina/fisiologia , Núcleo Supraquiasmático/patologia
10.
Brain Res ; 589(1): 124-8, 1992 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-1422812

RESUMO

The suprachiasmatic nuclei (SCN) of mutant anophthalmic (strain ZRDCT-An) and sighted control mice was examined using light microscopic methods for cytoarchitecture and immunocytochemistry for vasoactive intestinal polypeptide (VIP). The SCN of the anophthalmic mice were asymmetrical, and quite variable in cytoarchitecture. Immunocytochemistry for VIP revealed strong staining of cells and fibers. Within the SCN, the distribution of VIP-immunoreactive cells was more diffuse in anophthalmic mice than in the controls; immunoreactive neurons were frequently observed in ectopic locations in the mutant animals.


Assuntos
Anoftalmia/metabolismo , Retina/fisiologia , Núcleo Supraquiasmático/química , Peptídeo Intestinal Vasoativo/análise , Vias Aferentes/fisiologia , Animais , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes
11.
J Comp Neurol ; 316(4): 447-58, 1992 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-1577993

RESUMO

The current study used light microscopic immunocytochemistry to demonstrate and compare neuropeptide Y-like immunoreactivity (NPY-IR) in the diencephalon of the little brown bat (Myotis lucifugus) at different stages in its annual cycle of activity and hibernation. Animals were sacrificed in each of three discrete physiological states: euthermic, hypothermic, and hibernating. In general, NPY-IR was abundant in the hypothalamus and sparse in other diencephalic areas. Immunoreactivity was present in a number of pathways which project to or originate from diencephalic nuclei; these include the ansa peduncularis, medial forebrain bundle, inferior thalamic peduncle, stria terminalis, stria medullaris, mammillary peduncle, and dorsal longitudinal fasiculus. Dense fiber plexuses were present throughout the hypothalamus; however, NPY-IR was conspicuously absent from the suprachiasmatic nucleus. Immunoreactive perikarya were located in the supraoptic, dorsomedial, ventromedial, and arcuate nuclei, in the external division of the ventral lateral geniculate nucleus, and in the pineal gland. Localized changes in density and/or distribution of NPY-IR were correlated with changes in physiological state.


Assuntos
Quirópteros/fisiologia , Diencéfalo/metabolismo , Neuropeptídeo Y/metabolismo , Animais , Temperatura Corporal/fisiologia , Diencéfalo/imunologia , Hibernação/fisiologia , Hipotálamo/imunologia , Hipotálamo/metabolismo , Imuno-Histoquímica , Neurônios/metabolismo , Neuropeptídeo Y/imunologia , Tálamo/imunologia , Tálamo/metabolismo
12.
Brain Res ; 572(1-2): 325-8, 1992 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-1611531

RESUMO

Adult Sprague-Dawley rats were unilaterally enucleated under deep anesthesia and sacrificed 3-11 months post-operatively. The brains were removed and the suprachiasmatic nuclei were evaluated for vasoactive intestinal polypeptide (VIP)-like immunoreactivity. Our data show that expression of VIP is reduced in the nucleus that is deprived of retinal input.


Assuntos
Retina/fisiologia , Núcleo Supraquiasmático/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo , Animais , Enucleação Ocular , Técnicas Imunoenzimáticas , Ratos , Ratos Endogâmicos
13.
Brain Res ; 544(1): 108-17, 1991 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-1906770

RESUMO

MabQ155, a monoclonal antibody against synaptophysin, has been used to conduct a light microscopic survey of synaptogenesis in the suprachiasmatic nucleus of the perinatal rat. Synaptophysin is an integral component of synaptic vesicle membranes which is expressed in growth cones and growth cone filopodia as well as in mature synapses. With the light microscope, mabQ155 immunoreactivity in growth cones can be distinguished from that in presynaptic terminals on the basis of the size of immunoreactive puncta. The current study presents a qualitative and quantitative analysis of synaptogenesis from the day of birth (P0) to postnatal day 10 (P10). In our quantitative analysis we have used daily intervals during the first postnatal week, distinguished between growth cones and presynaptic terminals, and divided the suprachiasmatic nucleus into sampling regions that are related to the progress of synaptogenesis. Our data demonstrate regional differences in synaptogenesis within the suprachiasmatic nucleus (SCN), document the temporal progression from the penetration of growth cones to the appearance of mature synapses, and provide information about gradients of synaptogenesis in the nucleus during development.


Assuntos
Proteínas de Membrana/análise , Núcleo Supraquiasmático/crescimento & desenvolvimento , Sinapses/ultraestrutura , Vesículas Sinápticas/ultraestrutura , Envelhecimento , Animais , Anticorpos Monoclonais , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Imunoeletrônica , Proteínas do Tecido Nervoso/análise , Núcleo Supraquiasmático/anatomia & histologia , Núcleo Supraquiasmático/citologia , Membranas Sinápticas/ultraestrutura , Sinaptofisina
14.
Neurosci Lett ; 122(1): 25-8, 1991 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-2057132

RESUMO

Light microscopic immunocytochemistry for neuropeptide Y (NPY) has demonstrated the presence of a diffuse system of NPY-immunoreactive fibers in the cerebellum of Myotis lucifugus. These fibers gain access to the cerebellum by way of the superior cerebellar peduncle, and terminate on Purkinje cell dendrites and on neurons in the granule cell layer. The origin of cerebellar NPY and possible colocalization with norepinephrine are discussed.


Assuntos
Cerebelo/fisiologia , Quirópteros/fisiologia , Neuropeptídeo Y/fisiologia , Animais , Cerebelo/anatomia & histologia , Dendritos/metabolismo , Imuno-Histoquímica , Vias Neurais/fisiologia , Neurônios/metabolismo , Norepinefrina/metabolismo , Células de Purkinje/metabolismo
15.
Peptides ; 11(6): 1055-64, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-1982348

RESUMO

The development of somatostatin-immunoreactive (SS) neurons and processes in the rat visual cortex (VC) was studied in animals from embryonic day 20 (E20) to postnatal day 21 (D21). Three distinct patterns of immunoreactivity were seen. From E20 to birth (D0), VC was characterized by a small number of mainly bipolar SS neurons throughout the cortical plate. In the perinatal period, from D1 to D6, there were large numbers of immature immunoreactive neurons which were confined to layer VI and the subplate zone, a few bipolar neurons in the cortical plate and an extremely dense plexus of SS processes throughout the neuropil. The third phase, from D8 to weaning, was characterized by the absence of immature SS neurons, an increase in the number of multipolar SS neurons and a decrease in the density of SS fibers. By D15, the time of eye-opening, the number and distribution of SS neurons and processes was close to that seen in the adult. These results indicate that the SS system of neurons and fibers is among the earliest of the transmitter systems to be established in VC and suggests a role for the peptide in cortical organization as well as visual processing.


Assuntos
Somatostatina/análise , Córtex Visual/química , Córtex Visual/crescimento & desenvolvimento , Animais , Autorradiografia , Mapeamento Encefálico , Técnicas Imunoenzimáticas , Ratos , Ratos Endogâmicos , Córtex Visual/embriologia
16.
J Hirnforsch ; 31(1): 87-97, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2358657

RESUMO

The distribution of Cholecystokinin (CCK-8)-like immunoreactivity was mapped in the brain of the little brown bat, Myotis lucifugus, at three different and discrete levels of physiological activity: euthermic, hypothermic, and hibernating. Immunoreactive perikarya were present in the cerebral cortex, hippocampal formation, several nuclei of the olfactory and limbic systems, the ventral lateral geniculate nucleus, suprachiasmatic nucleus, medial geniculate nucleus, and caudate-putamen. Immunoreactive fibers were present in plexuses throughout the brain and in three major projection pathways: the medial forebrain bundle, the mammillary peduncle, and dorsal longitudinal fasciculus. Our data suggest two possible loci for CCK regulation of feeding behavior: a hypothalamic locus in the dorsomedial nucleus and a brainstem locus in the nucleus tractus solitarius.


Assuntos
Encéfalo/metabolismo , Quirópteros/metabolismo , Sincalida/metabolismo , Animais , Encéfalo/citologia , Imuno-Histoquímica
17.
Neurotoxicol Teratol ; 12(1): 47-56, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2314360

RESUMO

The effects of repeated SC administration of soman on schedule-controlled performance and brain pathology were studied in the rat. Soman suppressed response rates in both components of a multiple fixed interval 50-sec fixed-ratio 25 (mult. FI 50-sec FR 25) schedule of reinforcement, although all animals revealed marked tolerance to repeated drug administration. Response rates generally recovered to baseline levels within 1-3 sessions. Three of the six animals studied, however, demonstrated marked deterioration of steady state schedule performance, particularly during the FI 50-sec component of the multiple schedule. Compared to untreated controls, all soman-treated animals exhibited pathological changes in brain. The most salient finding was glial cell proliferation in layer 4 and deep parts of layer 3 of the cerebral cortex. Glial cell proliferation was most marked in animals that exhibited deterioration of steady state schedule performance.


Assuntos
Encéfalo/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Soman/toxicidade , Animais , Encéfalo/patologia , Córtex Cerebral/efeitos dos fármacos , Esquema de Medicação , Hipocampo/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos , Esquema de Reforço , Soman/administração & dosagem
18.
Brain Res ; 469(1-2): 308-12, 1988 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-3042096

RESUMO

Vasoactive intestinal polypeptide (VIP)-like immunoreactivity was examined in the suprachiasmatic nucleus (SCN) of the perinatal rat using the unlabeled antibody enzyme method of Sternberger. Our results showed that VIP-like immunoreactivity was present in cells and fibers of the SCN prior to birth. Immunoreactive neurons at this time appeared morphologically immature, and their distribution differed somewhat from that seen in the adult SCN.


Assuntos
Núcleo Supraquiasmático/citologia , Peptídeo Intestinal Vasoativo/análise , Animais , Feto , Técnicas Imunoenzimáticas , Ratos , Núcleo Supraquiasmático/embriologia
19.
Brain Res ; 441(1-2): 398-402, 1988 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-3282610

RESUMO

Vasoactive intestinal polypeptide (VIP)-like immunoreactivity in the anterior hypothalamic area (AHA) was studied in 15 bats which are seasonal hibernators, using the unlabeled antibody enzyme method of Sternberger. Our results showed that the density of immunoreactive fibers and terminal plexuses in the AHA was greatest in euthermic animals and decreased dramatically when body temperature and cardiac rate were depressed and animals entered hibernation.


Assuntos
Núcleo Hipotalâmico Anterior/fisiologia , Quirópteros/fisiologia , Hibernação , Peptídeo Intestinal Vasoativo/análise , Animais , Temperatura Corporal , Frequência Cardíaca , Técnicas Imunoenzimáticas , Peptídeo Intestinal Vasoativo/imunologia
20.
J Neurocytol ; 17(1): 117-29, 1988 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3047320

RESUMO

Vasoactive intestinal polypeptide (VIP)-like immunoreactivity has been examined in the brain of the little brown bat, Myotis lucifugus, using light microscopic immunocytochemistry and the indirect antibody enzyme method of Sternberger. Animals were sacrificed at three different and discrete levels of physiological activity: euthermic, hypothermic and hibernating. The density and distribution of immunoreactive neurons and fibres was compared in the three animal groups with the aid of a computerized image analysis system. Our results were compared with those of previous studies in laboratory species such as the rat and cat. Our study has demonstrated marked changes in the density of VIP-immunoreactive fibres and plexuses in the anterior hypothalamic area which correspond to the physiological state of the animal. In addition we have demonstrated the presence of VIP immunoreactive perikarya in a number of previously unreported locations. These include the paraventricular and periventricular hypothalamic nuclei, the linear raphe nucleus, nucleus interfascicularis, and in neurons embedded in the fibres of the dorsal tegmental decussation.


Assuntos
Química Encefálica , Quirópteros/metabolismo , Peptídeo Intestinal Vasoativo/análise , Animais , Temperatura Corporal , Córtex Cerebral/análise , Hibernação , Hipotálamo/análise , Técnicas Imunoenzimáticas , Bulbo/análise , Mesencéfalo/análise , Telencéfalo/análise
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