Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HYPOTHALAMUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,747 records · Page 97Linked to original sources
PubMed1984

A Golgi study on the neuronal morphology in the hypothalamus of the Japanese quail (Coturnix coturnix japonica). I. Tuberal and mammillary regions.

Neuronal morphology and dendritic architecture of the tuberal and mammillary regions in the hypothalamus of the quail (Coturnix coturnix japonica) were investigated by means of classical neuroanatomical methods (Bodian silver impregnation, Luxol-fast blue, cresyl violet, toluidine blue, rapid Golgi method). The tuberal region is characterized by isodendritic neurons, in particular: a) pyriform and bipolar neurons, occasionally arranged diagonally to the ventricular surface; b) CSF-contacting neurons, located subependymally or more deeply in the periventricular gray, which are especially abundant in the paraventricular organ and in the proximity of the median eminence; c) numerous multipolar neurons, endowed with stout, almost unbranched dendritic processes, occupying generally the medio-lateral areas of the hypothalamus. Some multipolar neurons display somata, pyramidal or ovoidal in shape, almost imperceptibly tapering into three or more dendritic trunks. These relatively straight and long dendrites are rich in dendritic spines. In the mammillary region, Golgi impregnation shows multipolar neurons of medium size, most likely belonging to the lateral mammillary nucleus.

Animals↗
PubMed1984

A Golgi-type study of the hypothalamus of the lizard, Calotes versicolor.

The hypothalamus of the garden lizard, Calotes versicolor, was investigated with the use of the rapid Golgi and Golgi-Cox techniques. Individual neurons belonging to different nuclear groups were identified and studied with respect to their position, orientation, nature, pattern of arborization and connections. Magnocellular neurons in the preoptic region (rapid Golgi method) are large, lobular, bipolar or multipolar elements characterized by smooth contours of their somata, and processes of differing caliber and pattern of branching. Parvocellular neurons were found to belong to the primitive and generalized isodendritic type displaying pyriform, fusiform or spindle-shaped somata. Each soma gives rise to two to four straight, sometimes curved processes, which show varying patterns of arborization. The branches extend toward the 'integrative area', comprised of medial and lateral neuropil, or among major hypothalamic tracts; they are suggested to establish extrahypothalamic contacts or to extend to adjoining nuclear zones where they may establish specific intrahypothalamic connections. CSF-contacting processes from some magnocellular and parvocellular neurons were encountered. In addition to drawing correlations between information obtained from Golgi- and Nissl preparations, an attempt has been made to understand the precise organization of neuronal elements and to study the scope and pattern of arborization in the hypothalamus of Calotes versicolor.

Animals↗
PubMed1985

CRF-containing neurons of the rat hypothalamus.

The immunoreactive CRF-neurons of the rat hypothalamus have been examined immunohistochemically employing anti-rat CRF serum. These neurons are confined to the paraventricular nucleus, dorsomedial-lateral hypothalamic area, and suprachiasmatic nucleus, and are, respectively, also immunoreactive to anti-Met-enk, -alpha-MSH, and -VIP sera. Intraventricular administration of colchicine (50 micrograms/5 microliters/rat) induces a dramatic enhancement of the immunostainability of the cell somata, and also accelerates the development of immunoreactivity of other stored peptides, especially in the paraventricular nucleus. The CRF-neurons respond to adrenalectomy by showing increased immunoreactivity and an increase in the number of cell bodies; in the dorsomedial-lateral area and suprachiasmatic nucleus, there is also an enhanced immunoreactivity for alpha-MSH and VIP, respectively. CRF-cells in the paraventricular nucleus become markedly hypertrophied, but do not show any enhanced immunoreactivity for Met-enk. Since the axons of the paraventricular neurons run to the median eminence, it is probable that they are involved with the endocrine control of hypophysial ACTH release. It is concluded that the CRF-containing neurons in rat hypothalamus consist of three types which are functionally and morphologically different.

Adrenalectomy↗
PubMed1986

Glucagon-related peptides in the rat hypothalamus.

Immunohistochemically, nerve fibers and terminals reacting with anti-N-terminal-specific but not with anti-C-terminal-specific glucagon antiserum were observed in the following rat hypothalamic regions: paraventricular nucleus, supraoptic nucleus, anterior hypothalamus, arcuate nucleus, ventromedial hypothalamic nucleus and median eminence. Few fibers and terminals were demonstrated in the lateral hypothalamic area and dorsomedial hypothalamic nucleus. Radioimmunoassay data indicated that the concentration of gut glucagon-like immunoreactivity was higher in the ventromedial nucleus than in the lateral hypothalamic area. In food-deprived conditions, this concentration increased in both these parts. This was also verified in immunostained preparations in which a marked enhancement of gut glucagon-like immunoreactivity-containing fibers and terminals was observed in many hypothalamic regions. Several immunoreactive cell bodies were found in the ventromedial and arcuate nuclei of starved rats. Both biochemical and morphological data suggest that glucagon-related peptides may act as neurotransmitters or neuromodulators in the hypothalamus and may be involved in the central regulatory mechanism related to feeding behavior and energy metabolism.

Animals↗
PubMed1976

Hypothalamus and cytodifferentiation of the foetal pituitary gland. Study in vivo.

To investigate whether the hypothalamus is involved in the cytodifferentiation of the anterior pituitary gland, rat foetuses were encephalectomized in utero on day 16 of pregnancy. Pituitary sections from encephalectomized and normal littermate foetuses were studied on day 21 with the immunofluorescence technique using antibodies anti alpha-MSH, anti beta-MSH, anti alpha-(17-39) ACTH and anti beta-(1-24) ACTH. On day 16, only the anti beta-MSH revealed a few cells in the pars distalis but not in the pars intermedia. On the other hand, on day 21, the pituitary cells reacting with antibodies anti alpha-MSH, anti beta-MSH and anti alpha-(17-39) ACTH were as numerous in the encephalectomized foetuses as in the normal littermate foetuses. The cells revealed with the antibody anti beta-(1-24) ACTH were less numerous and less fluorescent in the pars distalis and intermedia of the hypophysis of the encephalectomized foetuses. On day 21, the adrenals of the encephalectomized foetuses were atrophied in comparison with those of the normal littermate foetuses but they were larger than on day 16. These data suggest that the cytodifferentiation of the corticotroph and melanotroph cells of the hypophysis occurs without the influence of the hypothalamus which is necessary for the normal release of ACTH.

Adrenal Glands↗
PubMed1977

Immunocytochemical localization of the vasopressinergic and the oxytocinergic neurons in the human hypothalamus.

The human hypothalamic-neurohypophysial hormone-producing nuclei were investigated with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level. The size, shape and location of the supraoptic, paraventricular, accessory supraoptic and suprachiasmatic nuclei were determined. It was demonstrated in the human hypothalamus, as well as in the hypothalamus of other mammals, that vasopressin and oxytocin are synthesized in separate neurons. In each of the nuclei of the magnocellular neurosecretory system, the distribution, ratios and structural features of the vasopressinergic and oxytocinergic neurons were determined. It was shown that the human suprachiasmatic nuclei contain numerous neurophysin-vasopressin-producing neurons.

Female↗
PubMed1975

Immunoreactive LH-RH neurons in the hypothalamus identified by light and fluorescent microscopy.

The sites of luteinizing hormone-releasing hormone (LH-RH) neurons and their axonal pathways in the hypothalmi of rats and mice were studied by the immunoglobulin-peroxidase bridge technique and b) the immunofluorescent isothiocyanate technique, using rabbit antiserum to synthetic LH-RH. Both of these techniques give similar results concerning LH-RH localization both in rats and mice. The immunoreactive LH-RH positive neurons are about 18-26 mu in diameter, mostly angular, pyriform or spindle shaped and very rarely oval or round. Most of these neurons are generally scattered in the hypothalamus. In the preoptic and medial preshiasmatic areas, ventromedial, arcuate nuclei and ventrolateral-premammillary body, the neurons are numerous and mostly in groups of 3-6. In other areas of the hypothalamus surrounding the suprachiasmatic area, supraoptic area, paraventricular nuclei and the anterior hypothalamic area, the LH-RH neurons are few and scattered. Very few neurons occur in the median eminence or in the infundibular stem. Major projections of LH-RH neurons apparently originate from preoptic, prechiasmatic and surrounding suprachiasmatic area, and from the anterior hypothalamic area. The fibres run in the fabrillar zone, descend in the external infundibular zone, and finally terminate for the most part around the capillaries of the primary portal plexus of the hypophysis. Other major groups of fibres apparently originate from the arcuate and ventromedial neurons. These fibres bend above the fibrous zone for some distance, ultimately descending in the zona palisadica and zona granulosa of the median eminence, towards the capillaries. The fibers of the ventrolateral-premammillary neurons are seen on the floor of the premammillary recess of 3rd ventricle and apparently terminate close to the capillaries in the infundibular region. Most of the LH-RH nerve fibres terminate near the primary portal plexus of the hypophysis, while some terminate in the pars tuberalis and a few seem to terminate in the 3rd ventricle. The LH-RH antiserum is ineffective after absorption with the antigen, so the staining reaction appears to be specific for LH-RH.

Animals↗
PubMed1992

Acoustic modulation of neural activity in the preoptic area and ventral hypothalamus of the green treefrog (Hyla cinerea).

Responses of neurons in the preoptic area and ventral hypothalamus to conspecific mating calls or white noise bursts were examined in male green treefrogs (Hyla cinerea) during different seasons. In the winter, 34.3% of preoptic neurons and 46.7% of ventral hypothalamic cells demonstrated significant changes in activity level during presentation of a conspecific mating call. In contrast, only 13.3% of preoptic units and 16.7% of ventral hypothalamic cells responded to the white noise. The percentage of preoptic and hypothalamic units responding to the advertisement call did not differ significantly during the summer breeding season. Type I units exhibited a dramatic increase in activity during acoustic stimulation followed by a rapid return to baseline activity levels after stimulus offset. Type II cells showed a robust activity increase during stimulation, but maintained an intermediate activity level after stimulus offset. In the preoptic area, a third response type exhibited suppressed activity during acoustic stimulation. Although seasonal condition did not alter the percentage of acoustically responsive units within either nucleus, the proportion of Type I units in the ventral hypothalamus was greatest during the summer.

Acoustic Stimulation↗
PubMed1989

Immunocytochemical localization of the gonadotropin-releasing hormone-associated peptide portion of the LHRH precursor in the hypothalamus and extrahypothalamic regions of the rat central nervous system.

The gonadotropin-releasing hormone-associated peptide (GAP) of the LHRH precursor and the decapeptide LHRH were localized in the rat brain by immunocytochemistry in 12- to 18-day-old animals, by use of thick Vibratome sections and nickel intensification of the diaminobenzidine-reaction product. Our results indicate that the GAP portion of the LHRH precursor is present in the same population of neurons that contain LHRH in the rat brain. An important difference observed was that the GAP antiserum, in contrast to LHRH antisera, stained several perikarya in the medial basal hypothalamus. GAP-immunoreactive perikarya were observed in the following regions: the olfactory bulb and tubercle, diagonal band of Broca, medial septum, medial preoptic and suprachiasmatic areas, anterior and lateral hypothalamus, and several regions of the hippocampus. In addition to the preoptico-terminal and the septo-preoptico-infundibular pathways, we also observed GAP-immunopositive processes in several major tracts and areas of the brain, including the amygdala, stria terminals, stria medullaris thalami, fasciculus retroflexus, stria longitudinalis medialis, periventricular plexus, periaqueductal gray of the mesencephalon and extra-cerebral regions, such as the nervus terminalis and its associated ganglion. These results confirm the specificity of previous immunocytochemical results obtained with antisera to LHRH. The presence of GAP immunoreactivity in nerve terminals of the rat brain indicates that GAP or a GAP-like peptide is located in the proper site to serve as a hypophysiotropic substance and/or as a neurotransmitter or neuromodulator.

Animals↗
PubMed1979

The location of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence. Experimental immunohistochemistry and radioimmunoassay.

The location of the perikarya of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence were studied by immunohistochemistry and radioimmunoassay after placing stereotaxic electrolytic lesions in several parts of the hypothalamus. The principal location of the cell somata was found to be in the ventral part of the medial preoptic area; their pathways were classified into a main baso-lateral pathway and an accessory descending pathway branching off from the former. The main pathway was found to cross in the vicinity of the corresponding neuronal perikarya. The central median eminence and the dorsal and ventral walls of the tubero-infundibular sulcus of the caudal part of the median eminence are innervated mainly by the baso-lateral pathway. On the other hand, the rostral and most caudal protions of the median eminence are innervated principally by the descending pathway and have a subsidiary dual innervation. The projection of LH-RH neurons to the OVLT is believed to originate from perikarya adjacent to this circumventricular organ.

Animals↗
PubMed1979

Localization of ACTH in the human hypothalamus.

Using an antiserum to porcine ACTH and the unlabeled antibody preoxidase-antiperoxidase technique, we have found that ACTH is present in neuronal cell bodies located exclusively in the arcuate nucleus of the human hypothalamus. ACTH-containing fibers are distributed extensively throughout the hypothalamus with a greatest density in the periventricular nucleus. No concentration of ACTH fibers could be observed in the neurovascular zone of the pituitary stalk.

Adrenocorticotropic Hormone↗
PubMed1979

Immunocytochemical identification of vasopressinergic and oxytocinergic neurons in the hypothalamus of the cat.

Our immunocytochemical investigation of the magnocellular neuroendocrine cells in the cat hypothalamus reveals a mixture of vasopressin (VP)- and oxytocin (OT)-containing neurons in the supraoptic (NSO), the paraventricular (NPV) and in five accessory nuclei (NAC). We describe the lateral hypothalamic nucleus (NLH), a new accessory nucleus, lying at the junction of the internal capsule and pallidum, and possibly involved in drinking behavior. Previously characterized incompletely in mammals, the four other accessory nuclei consist of the circularis (NC), anterior fornical (NAF), posterior fornical (NPF) and retrochiasmatic (NRC). The two peptidergic cell types, VP and OT, are equally mixed in the NPV and the NAC, but in the NSO VP neurons predominate. The perikarya of these VP and OT neurons do not show distinct morphological differences at the level of light microscopy. The organization of magnocellular neuroscretory neurons in the cat hypothalamus closely resembles that described in other mammals with the exception of the unique presence of the lateral hypothalamic accessory nucleus.

Animals↗
PubMed1979

Immunocytochemical localization of somatostatin-containing neurons in the rat hypothalamus.

The rat hypothalamus was studied at the light microscopic level with the use of single and double immunocytochemical staining methods. It was shown that the rat supraoptic and paraventricular hypothalamic nuclei, and their accessory neurosecretory nuclei, do not contain magnocellular somatostatin neurons. The distribution of the hypothalamic parvocellular somatostatin cells is described. The parvocellular component of the rat hypothalamic paraventricular nucleus is, at least partly, composed of somatostatin cells: they form a fairly well circumscribed periventricular cell mass. The rat suprachiasmatic nuclei contain separate somatostatin neurons and vasopressin neurons. Scattered somatostatin cells are present in the entire arcuate nucleus. In addition to the periventricular somatostatin cells located in the preopticanterior hypothalamic area in the arcuate nucleus, the rat hypothalamus also contains numerous scattered somatostatin cells located distant from the third ventricle.

Animals↗
PubMed1983

Ontogenetic studies on the topographical heterogeneity of somatostatin-containing neurons in rat hypothalamus.

The ontogeny of the somatostatin-containing neuron system was investigated by light-microscopic immunohistochemistry. During development, immunoreactive somatostatin-containing neurons arise from three discrete regions of the neuroepithelium of the third ventricle and show a chronological difference. The neurons are first evident within the third ventricle floor on day 12.5 of gestation; they move thereafter to the arcuate nucleus. The second generation occurs in the dorsal region of the arcuate nucleus during days 17.5-19.5; these neurons migrate sequentially into the arcuate-ventromedial nuclear region. The third generation is recognized in the neuroepithelial cell layer of the rostral hypothalamus on day 17.5 of gestation; these cells move to the periventricular area. This latter generation is most prominent during days 3-6 after birth, and some of the cells are seen sporadically even up to day 20. The first two generations give rise to the somatostatin neuron system in the arcuate-ventromedial nuclear region, while the latter gives rise to that in the rostral periventricular region in the adult rat hypothalamus.

Animals↗
PubMed1989

D2- but not D1-dopamine receptors are involved in the inhibitory control of alpha-melanocyte-stimulating hormone release from the rat hypothalamus.

Release of alpha-melanocyte-stimulating hormone (alpha-MSH) from slices of rat hypothalamus superfused with artificial cerebro-spinal fluid (ACSF) was quantified by radioimmunoassay. Addition of 10(-6) M quinpirole, a D2-dopamine receptor agonist, to the superfusion medium caused a significant (P less than 0.001) reduction in the amount of alpha-MSH released upon depolarisation with 50 mM potassium from 319 +/- 37% to 110 +/- 16% of basal release in normal ACSF (mean +/- S.E.M.). Basal peptide release in the presence of quinpirole was unaffected. Sulpiride, a D2-dopamine receptor antagonist, at a concentration of 10(-6) M, induced a significant (P less than 0.05) increase of both basal and potassium-stimulated alpha-MSH release to 203 +/- 21% and 447 +/- 88% of basal release in normal ACSF respectively. The latter increases were abolished when sulpiride and quinpirole were added in combination. SK&F 38393-A and SCH 23390, a D1-dopamine agonist and antagonist respectively, had no significant effect on either basal or potassium-stimulated alpha-MSH release. It is proposed that endogenous dopamine exerts an inhibitory control on alpha-MSH release from the rat hypothalamus via D2-dopamine receptors and that in isolated hypothalamic slices there is a tonic inhibition of peptide release due to the activity of this system.

Animals↗
PubMed1995

Induction from posterior hypothalamus is essential for the development of the pituitary proopiomelacortin (POMC) cells of the toad (Bufo japonicus).

The role of the posterior hypothalamus in the development of the epithelial hypophysis was studied in Bufo embryos. In animals from which the central part of the neural plate (NP) had been surgically removed at the open neurula stage, the infundibulum did not develop, and the epithelial hypophysis was formed away from the normal site without morphological connection with the brain. Immunoreactive MSH cells and ACTH cells, i.e., the pituitary POMC cells, were not detected in any of the surgically treated animals, while other types of secretory cells (PRL, GH, TSH and GTH cells) were invariably present. In view of the fact that POMC cells originate in the anterior neural ridge, and not in the neural plate, the embryonic brain seems to exert an inductive influence upon the primordial pituitary POMC cells. Since these cells differentiate in a tail graft, isolated from the brain at a later stage (tail-bud stage), the inductive stimuli must be conveyed from/via the posterior hypothalamus to the pituitary anlage between the open neurula and the tail-bud stages.

Adrenocorticotropic Hormone↗
PubMed1992

In situ hybridization of corticotropin-releasing factor-encoding messenger RNA in the hypothalamus of the white sucker, Catostomus commersoni.

In situ hybridization procedure with a 32P-labelled synthetic oligonucleotide probe was used to detect corticotropin-releasing factor-encoding messenger RNA (CRF mRNA) in the hypothalamus of the white sucker, Catostomus commersoni. Adjacent sections were immunostained by a sucker CRF-specific antiserum. CRF mRNA-containing neurons were identified by autoradiography in the magnocellular and parvocellular subdivisions of the preoptic nucleus (PON). Many of these neurons were also immunostained by sucker antiserum, showing the same distribution patterns. These results confirm the presence of CRF mRNA and CRF peptide in the white sucker hypothalamus and support the view that the magnocellular and parvocellular neurons of the PON may be involved in the control of adrenocorticotropic hormone secretion from the pituitary in the white sucker.

Animals↗
PubMed1989

Interconnections between hypothalamus and cerebellum.

The cerebellum and hypothalamus are interconnected through a multitude of direct (monosynaptic) and indirect (polysynaptic) pathways. Direct hypothalamocerebellar fibres are mainly uncrossed and reach all parts of the cerebellar cortex and nuclei. They are neither mossy fibres nor climbing fibres, but appear to terminate in all layers of the cerebellar cortex as multilayered fibres. At least some of the hypothalamocerebellar fibres are histaminergic, and it appears that a small proportion of the hypothalamocerebellar neurons contain GABA. Indirect hypothalamocerebellar connections may be relayed through various brain stem nuclei. The hypothalamo-ponto-cerebellar pathway, which has a contralateral predominance, appears to be the quantitatively most important of these. The direct cerebellohypothalamic projection originates from the cerebellar nuclei and terminates in the posterior hypothalamus, in the same regions where the direct hypothalamocerebellar pathway has its main origin. Indirect cerebellohypothalamic connections with brain stem relays have also been demonstrated. The functions of hypothalamocerebellar circuits are so far unknown. However, these pathways are probably involved in the coordination and integration of somatic as well as non-somatic responses to a given set of inputs.

Animals↗