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Showing papers on "Hypothalamus published in 1982"


Journal ArticleDOI
TL;DR: The results indicate that both oxytocin‐ and vasopressin‐stained cells in the PVH project to the spinal cord and to the dorsal vagal complex, although about three times as many oxytocinstained cells were doubly labeled after injections centered in either terminal field, suggesting that additional neuroactive substances are contained within these pathways.
Abstract: A method that allows the concurrent localization of an antigen and a retrogradely transported fluorescent dye (true blue) was used to identify, immunohistochemically, cells in the paraventricular nucleus of the hypothalamus (PVH) that project to autonomic centers in the brainstem or in the spinal cord of the adult albino rat. After placing injections of true blue in the dorsal vagal complex or in upper thoracic segments of the spinal cord, series of evenly spaced sections through the PVH were stained with antisera directed against oxytocin, vasopressin, somatostatin, methionine-enkephalin, or leucine-encephalin. The results indicate that both oxytocin- and vasopressin-stained cells in the PVH project to the spinal cord and (or) to the dorsal vagal complex, although about three times as many oxytocinstained cells were doubly labeled after injections centered in either terminal field. The oxytocin- and vasopressin-stained cells that give rise to these long descending projections were found primarily in caudal parts of the parvo cellular division of the PVH, where immunoreactive cells were shown to be significantly smaller than oxytocin- and vasopressin-stained cells in parts of the nucleus that project to the posterior pituitary. Small populations of cells in the PVH that cross-react with antisera against somatostatin, leucine-enkephalin, or methionine-enkephalin were also shown to project directly to the region of the dorsal vagal complex and to the spinal cord, and to have a unique distribution within the PVH. Collectively, the total number of doubly labeled cells that were identified in these experiments accounts for only about one-fourth of the total number of PVH neurons with long descending projections, thus suggesting that additional neuroactive substances are contained within these pathways.

1,103 citations


Journal ArticleDOI
23 Sep 1982-Nature
TL;DR: It is reported here that the new CRF is more potent than vasopressin in releasing ACTH and potentiation of CRF activity with steep dose–response characteristics was observed, suggesting that thenew CRF does not account for all the non-vasopressIn portion of the CRF complex.
Abstract: Initially the hypothalamic factor responsible for the release of corticotropin (CRF), was thought to be a simple peptide. More recent work has led to the conclusion that CRF is a multifactorial complex. In 1979 we proposed that vasopressin, much disputed as a CRF candidate, was a major constituent of the complex, interacting with a potentiating the CRF activity of the other component(s). The recent characterization of a 41 residue ovine hypothalamic peptide capable of releasing adrenocorticotropic hormone (ACTH) in a dose-related manner has allowed us to compare its CRF bioactivity with that of vasopressin and simple extracts of the hypothalamus, and to investigate any interaction it may have with vasopressin and other hypothalamic factors in the release of ACTH. We report here that the new CRF is more potent than vasopressin in releasing ACTH. When given simultaneously with vasopressin a fourfold potentiation of CRF activity with steep dose-response characteristics were observed. It also potentiated vasopressin-free hypothalamic extracts, suggesting that a new CRF does not account for all the nonvasopressin portion of the CRF complex.

943 citations


Journal ArticleDOI
TL;DR: It is concluded that each pulsatile LH secretory episode results from a pulsatile discharge of GnRH from the hypothalamus via the portal network.
Abstract: Hypothalamo-hypophyseal portal blood has been collected from conscious OVX ewes by a procedure that permits maintenance of pituitary function. GnRH was measured in portal plasma and LH was measured in peripheral (jugular) plasma. The data demonstrate exact synchrony of GnRH and LH secretion. We conclude that each pulsatile LH secretory episode results from a pulsatile discharge of GnRH from the hypothalamus via the portal network

858 citations


Journal ArticleDOI
TL;DR: The widespread but selective distribution of neurons containing CRF-like immunoreactivity supports the neuroendocrine role of this peptide and suggests that CRF, similarly to other neuropeptides, may also function as a neuromodulator throughout the brain.
Abstract: The immunocytochemical localization of neurons containing the 41 amino acid peptide corticotropin-releasing factor (CRF) in the rat brain is described. The detection of CRF-like immunoreactivity in neurons was facilitated by colchicine pretreatment of the rats and by silver intensification of the diaminobenzidine end-product. The presence of immunoreactive CRF in perikarya, neuronal processes, and terminals in all major subdivisions of the rat brain is demonstrated. Aggregates of CRF-immunoreactive perikarya are found in the paraventricular, supraoptic, medial and periventricular preoptic, and premammillary nuclei of the hypothalamus, the bed nuclei of the stria terminalis and of the anterior commissure, the medial septal nucleus, the nucleus accumbens, the central amygdaloid nucleus, the olfactory bulb, the locus ceruleus, the parabrachial nucleus, the superior and inferior colliculus, and the medial vestibular nucleus. A few scattered perikarya with CRF-like immunoreactivity are present along the paraventriculo-infundibular pathway, in the anterior hypothalamus, the cerebral cortex, the hippocampus, and the periaqueductal gray of the mesencephalon and pons. Processes with CRF-like immunoreactivity are present in all of the above areas as well as in the cerebellum. The densest accumulation of CRF-immunoreactive terminals is seen in the external zone of the median eminence, with some immunoreactive CRF also present in the internal zone. The widespread but selective distribution of neurons containing CRF-like immunoreactivity supports the neuroendocrine role of this peptide and suggests that CRF, similarly to other neuropeptides, may also function as a neuromodulator throughout the brain.

410 citations


Journal ArticleDOI
TL;DR: Antibodies to synthetic ovine corticotropin releasing factor were used to localize nerve fibers and cell bodies in rat brain to send a rich fiber plexus to the median eminence and less dense fiber connections to other hypothalamic and midbrain targets.

359 citations


Journal ArticleDOI
TL;DR: The connections of the subfornical organ (SFO) wer investigated by using the HRP technique and labeled cells were observed in the median preoptic nucleus, below the ependyma of the third ventricle, in the dorsal pre optic region near the anterior commissure, and diffusely throughout the medial preopti and anterior bypothalamic areas.
Abstract: The connections of the subfornical organ (SFO) wer investigated by using the HRP technique. Injections into the SFO labeled neurons in the medial septum, but not in lateral septum nor in the diagonal band nucleus. Labeled cells were observed in the median preoptic nucleus, below the ependyma of the third ventricle, in the dorsal preoptic region near the anterior commissure, and diffusely throughout the medial preoptic and anterior bypothalamic areas. Fibers were followed from the ventral stalk of the SFO. Precommissural fibers enter the median preoptic nucleus where many of them appear to terminate. Others continue on to the medial septum, the OVLT, the supraoptic nucleus, and the suprachiasmatic nucleus, HRP injections into the median preoptic nucleus labled many neurons in the SFO. Postcommissural fibers reach the hypothalamus by descending along the walls of the ventricle in the subependymal space, by traveling in the columns of the fornix and the medial corticohypothalamic tract, or by passing through the paraventricular nucleus of the thalamus. Some postcommissural fibers turn rostrally and enter the median preoptic nucleus while others join precommissural fibers bound for the supraoptic nucleus. More caudally directed fibers appear to innervate the paraventricular nucleus of the hypothalamus and the medial preoptic and anterior hypothalamic areas. HRP injections into the paraventricular nucleus of the hypothalamus labeled neurons in the SFO. These finding corroborate and extend previous work in describing neural connections between two brain regions that are important for fluid blance.

347 citations


Journal ArticleDOI
TL;DR: A novel projection of LHRH fibers for the rat was found originating from supracallosal neurons and coursing through both cingulate and neocortex, and fewer positive cells in the anterior hypothalamic area and the region of the supraoptic commissure.
Abstract: Immunocytochemical procedures on thick, unembedded sections were used to visualize the neurons and their processes that contain LHRH-immunoreactive material in the rat central nervous system (CNS). In animals pretreated with colchicine (75 μg, intraventricularly), cell bodies could be observed as far anterior as the olfactory bulb and posterior to the retrochiasmatic area of the basal hypothalamus. Several new observations for the rat were made in this study, including LHRH neurons in the accessory olfactory bulb and other olfactory-related structures, and in the anterior hippocampus and the induseum griseum. As in studies from other laboratories, we observed many LHRH cells in the periventricular medial preoptic area, diagonal band of Broca and septal nuclei, and fewer positive cells in the anterior hypothalamic area and the region of the supraoptic commissure. The LHRH fibers from all of these cells are widely dispersed in the CNS. In addition to the dense innervation of the median eminence, positive fibers are found innervating other circumventricular organs, coursing close to the ependymal wall of the ventricular system or in close association with cerebral arteries and areas of the pia mater and subarachnoid space. LHRH fibers may also innervate neurons in several regions of the CNS. A novel projection of LHRH fibers for the rat was found originating from supracallosal neurons and coursing through both cingulate and neocortex. The possible distribution of efferents from each LHRH cell group is discussed.

327 citations


Journal ArticleDOI
TL;DR: The distribution of gamma-aminobutyric acid nerve fibers and cell bodies in the rat hypothalamus and pituitary gland was immunohistochemically examined and provided a morphological basis by which GABA of hypothalamic origin may regulate the neuroendocrine system.
Abstract: The distribution of γ-aminobutyric acid (GABA) nerve fibers and cell bodies in the rat hypothalamus and pituitary gland was immunohistochemically examined using antibodies against the GABA-synthesizin

306 citations


Journal ArticleDOI
TL;DR: Observations in the suprachiasmatic nucleus of the rat hypothalamus provide further information on the organization of afferents to the rat SCN and demonstrate that the vLGN projection is chemically distinct from other SCN afferentS.
Abstract: The distribution of avian pancreatic polypeptide-like (APP) immunoreactivity was investigated in the suprachiasmatic nucleus (SCN) of the rat hypothalamus with immunohistochemical methods. Specificity of the antisera was established by the absence of all immunoreactive staining in tissue incubated in antisera which had been preabsorbed with the pure APP antigen. In addition, the antisera exhibited no significant cross reactivity with vasoactive intestinal polypeptide, vasopressin, somatostatin, or secretin. Within the rat SCN, APP immunoreactivity is restricted to varicose axons in the ventral and lateral aspects of the nucleus; the dorsomedial component of the nucleus is totally devoid of immunoreactivity and immunoreactive perikarya are not present in any portion of the SCN. The immunoreactive axons in the ventrolateral portion of the nucleus form an extensive plexus which is distributed in a pattern closely corresponding to the distribution of retinal and ventral lateral geniculate (vLGN) efferents to the SCN. No immunoreactive perikarya are observed in the retina following immunoperoxidase staining for APP and neither unilateral nor bilateral enucleation causes an observable alteration in the pattern of APP axon distribution within the SCN, thus indicating that the fiber plexus is not of retinal origin. In contrast, APP immunoreactive neurons are present in the same area of the vLGN in which retrogradely filled neurons have been demonstrated following iontophoretic injection of HRP into the SCN. Bilateral electrolytic lesions of the vLGN result in a total loss of immunoreactive axons in both SCN. Unilateral vLGN lesions cause a loss of approximately 60 to 75% of the immunoreactive fibers in the ipsilateral SCN with a lesser contralateral loss. These observations provide further information on the organization of afferents to the rat SCN and demonstrate that the vLGN projection is chemically distinct from other SCN afferents.

301 citations


Journal ArticleDOI
TL;DR: The distribution of immunoreactive TRH in the rat hypothalamus and pituitary was demonstrated using the peroxidase-antiperoxidases technique after rapid fixation of the rat brain with 5% acrolein, consistent with the role of TRH as a hypophysiotropic hormone, a regulator of the posterior pituitsary, and a neurotransmitter or neuromodulator of neurons in other regions of the hypothalamus.
Abstract: The distribution of immunoreactive TRH in the rat hypothalamus and pituitary was demonstrated using the peroxidase-antiperoxidase technique after rapid fixation of the rat brain with 5% acrolein. Widespread reaction product was identified in neuronal processes throughout the hypothalamus, with dense labeling in the median eminence, dorsomedial nucleus, parvocellular division of the paraventricular nucleus, perifornical region, periventricular nucleus, and organum vasculosum of the lamina terminalis. A striking accumulation of immunoreactive TRH was also noted throughout the posterior pituitary, where fibers appeared to terminate in grape-like swellings. Peroxidase-positive perikarya were best seen after colchicine pretreatment and were distributed in many regions of the hypothalamus. The greatest density of immunoreactive neurons was in the suprachiasmatic preoptic nucleus, parvocellular subdivision of the paraventricular nucleus, perifornical region, dorsomedial nucleus, and baso-lateral hypothalamus. These data are consistent with the role of TRH as a hypophysiotropic hormone, a regulator of the posterior pituitary, and a neurotransmitter or neuromodulator of neurons in other regions of the hypothalamus.

290 citations


Journal ArticleDOI
20 May 1982-Nature
TL;DR: The discovery of large amounts of oxytocin within the ovine corpus luteum reported here may provide an explanation of why there may exist different controls of reflex release and basal secretion of Oxytocin.
Abstract: Oxytocin is a nonapeptide hormone produced by the hypothalamus and released from the posterior pituitary. It is cleaved from a large molecular weight precursor which is synthesized in cell bodies of hypothalamic magnocellular neurones and then packaged into membrane-bound granules1. During axonal transport the precursor is cleaved to produce oxytocin and an oxytocin-related neurophysin. Apart from its established roles in lactation and labour, oxytocin is thought to be an important regulator of the oestrous cycle; it causes luteolysis in cattle2 and immunization against oxytocin increases the length of the ovine oestrous cycle3, McCracken4 has proposed that oxytocin acts by stimulating prostaglandin F2α (PGF2α) release from the uterine endometrium and that steroid hormones regulate PGF2α secretion by altering the availability of endometrial oxytocin receptors4,5. Steriods may also have a direct influence on oxytocin release from the posterior pituitary, oestradiol-17β increasing and progesterone inhibiting oxytocin secretion in response to vaginal distension in the goat6,7. However, recent radioimmunoassay (RIA) measurements of peripheral oxytocin levels during the ovine oestrous cycle8–10 consistently show that oxytocin and progesterone concentrations increase and decrease in synchrony during the luteal phase, reaching basal levels after luteolysis at a time when oestradiol-17β titres are known to rise11. Therefore, there may exist different controls of reflex release and basal secretion of oxytocin, and our discovery of large amounts of oxytocin within the ovine corpus luteum reported here may provide an explanation.

Journal ArticleDOI
TL;DR: In this paper, a method to minimize cytosol progestin receptor loss during freezing in order to localize the quantify estrogen-inducible progesterin receptors in individual nuclei of the female rat brain was proposed.
Abstract: We have utilized a method to minimize cytosol progestin receptor loss during freezing in order to localize the quantify estrogen-inducible progestin receptors in individual nuclei of the female rat brain. Ovariectomized females received estradiol benzoate (20 micrograms for 3 days) or vehicle prior to sacrifice. All animals were perfused with cold distilled H2O containing the cryoprotective compound, dimethyl sulfoxide (DMSO; 10% (v/v)). Thirty-one nuclei or brain regions were removed from frozen sections (300 micrometers) according to the method of Palkovits (Palkovits, M. (1973) Brain Res. 59: 449–450) and were assayed in vitro using a synthetic radioligand, [3H]R5020. In ovariectomized animals perfused with DMSO, a basal level (1 to 8 fmol/mg of protein) of progestin receptors was observed in a variety of preoptic, hypothalamic, and limbic structures. Moreover, estrogen treatment induced high levels (24 to 49 fmol/mg of protein) of progestin receptors in regions of the preoptic area of hypothalamus which contain high levels of estrogen receptors. These regions included the medial, periventricular, and superchiasmatic nuclei of the preoptic area, the periventricular anterior hypothalamus, the ventromedial nucleus, and the arcuate-median eminence. Moderate levels (2 to 8 fmol/mg of protein) of progestin receptors were induced by estrogen in other hypothalamic and limbic structures, including the anterior and lateral hypothalamus, the bed nucleus of the stria terminalis, the cingulate cortex, the medial amygdaloid nucleus, and the CA subfield of the hippocampus. By contrast, some areas, such as the caudate-putamen and the supraoptic nucleus, were devoid of both estrogen-inducible and uninduced progestin receptors. These results support the hypothesis that progesterone action in the central nervous system is mediated by cytosol receptors in discrete brain regions and provide the first quantitative map of progestin binding in a vertebrate brain.

Journal ArticleDOI
08 Jul 1982-Nature
TL;DR: It is reported here that the dopamine antagonist spiperone does not affect the release of either oxytocin or vasopressin from the isolated rat neurohypophysis, and the opiate antagonist naloxone markedly enhances the electrical stimulation of oxytocIn release, but has no effect on vasoppressin release.
Abstract: The neurohypophysis not only contains the nerve endings of the oxytocin- and vasopressin-secreting neurones of the hypothalamus, but also receives both dopamine1- and opiate peptide2,3-containing nerve fibres. This secondary innervation may regulate hormone secretion at the level of the nerve terminals by an action analogous to presynaptic inhibition4. Electrical stimulation of the isolated neurohypophysis releases oxytocin and vasopressin in amounts readily detectable by radio-immunoassay, and presumably also releases dopamine5 and endogenous opiates. If these neurosecretory products are indeed regulators of hormone release, then specific antagonists to dopamine and opiates should modify the electrically stimulated release of hormone. We report here that the dopamine antagonist spiperone does not affect the release of either oxytocin or vasopressin from the isolated rat neurohypophysis. In contrast, the opiate antagonist naloxone markedly enhances the electrical stimulation of oxytocin release, but has no effect on vasopressin release. Thus an endogenous opiate, released by electrical stimulation of the isolated neurohypophysis, inhibits the release of oxytocin, but this opiate control does not appear to be exerted on the vasopressin-secreting terminals. We have not found similar evidence that endogenous neuro-hypophysial dopamine regulates hormone release.

Journal ArticleDOI
TL;DR: Findings indicate that the paraventricular nucleus and possibly the supraoptic nucleus form the major source for vasopressinergic pathways in the brain.

Journal ArticleDOI
TL;DR: The episodic pulses of GH secretion appear to be due to a positive drive by hypothai amic GRF rather than to a periodic removal of the inhibitory activity of somatostatin.
Abstract: Infusion over 1 hour of a monoclonal antibody specific for rat hypothaiamic growth hormone releasing factor CGRF) abruptly abolishes the pulsatile secretion of growth hormone (GH) in normal nonrestrained rats. Resumption of the pulsatile secretion of GH occurs 2 to 3 days later. The episodic pulses of GH secretion thus appear to be due to a positive drive by hypothai amic GRF rather than to a periodic removal of the inhibitory activity of somatostatin.

Journal ArticleDOI
TL;DR: The hypothesis that adrenocorticotropic hormone/endorphin peptides previously detected in the hypothalamus and amygdala with immunological techniques are synthesized in these tissues from a precursor similar to pro-opiomelanocortin in the pituitary is supported.

Journal ArticleDOI
TL;DR: The hypothesis that a reduction in the number of brain adrenergic receptors is one of the biochemical factors underlying adaptation to stress is supported.

Journal ArticleDOI
TL;DR: The efferent connections of the posterior hypothalamus have been analyzed autoradiographically in a series of eight cynomolgus monkey brains with injections of 3H‐amino acids in different regions of the mamillary complex and the surrounding areas.
Abstract: The efferent connections of the posterior hypothalamus have been analyzed autoradiographically in a series of eight cynomolgus monkey (Macaca fascicularis) brains with injections of 3H-amino acids in different regions of the mamillary complex and the surrounding areas. The medial mamillary nucleus was found to project through the mamillothalamic tract to the ipsilateral anteroventral, anteromedial, and interanteromedial nuclei, and by way of the mamillotegmental tract principally to the deep tegmental nucleus (of Gudden). It also appears to contribute fibers to the medial forebrain bundle, some of which reach as far rostrally as the medial septal nucleus. The lateral mamillary nucleus projects through the mamillothalamic tract bilaterally upon the anterodorsal nuclei of the thalamus, and through the mamillotegmental system to the dorsal tegmental nucleus; it also appears to contribute fibers to the medial forebrain bundle. The supramamillary area has extensive ascending and descending connections that are distributed with the medial forebrain bundle to the hypothalamus and rostral midbrain; in addition, it gives rise to an unusually well-defined projection to field CA2 of the hippocampus and to a narrow zone overlying the outer part of the granule cell layer and the adjoining part of the molecular layer of the dentate gyrus. We have not been able to distinguish the connections of the posterior hypothalamic nucleus from those of the caudal part of the lateral hypothalamic area: they both appear to contribute substantially to the ascending components of the medial forebrain bundle, and through its descending projection to the tegmental fields of the midbrain, the nucleus centralis superior of the raphe complex, the locus coeruleus, and the central gray as far caudally as the facial nerve. Their further projections to the spinal cord were not examined. Viewed broadly, and in the light of previous work, our observations confirm, once again, the constancy of the connections of the hypothalamus in the mammalian brain, and the pivotal position that the posterior hypothalamus occupies in the elaborate system of connections that links the limbic areas of the forebrain with the complex of structures that Nauta has aptly designated the "midbrain limbic region."

Journal ArticleDOI
TL;DR: The dispersion of LHRH cells over many nuclear groups may allow for the integration of afferents from divergent regions of the neuraxis to mediate both tonic and phasic gonadotropin secretion in the rat.
Abstract: The purpose of this study was to determine the distribution of luteinizing hormone-releasing hormone (LHRH) cells and pathways projecting to the median eminence and organum vasculosum of the lamina terminalis in the hypothalamus of the rat. Immunopositive LHRH was detected by the PAP method of immunocytochemistry on vibratome sections without embedding. Female rats were ovariectomized and treated with estradiol benzoate or implanted with estradiol capsules prior to sacrifice in order to minimize variations in LH and ultimately to maximize hypothalamic LHRH content. Immunoreactive LHRH perikarya are diffusely aggregated across several nuclear groups: nucleus of the vertical limb of the diagonal band of Broca, medial septal nucleus, medians preoptic nucleus, rostral and medial preoptic areas, anterior hypothalamic area, and lateral and basal hypothalamic areas. The aggregate of LHRH cells when projected upon a horizontal plane resembles the form of a V bisected by the third ventricle. The apex of the V is directed rostrally toward the midline nuclear groups whereas the ends of the V incline ventrally toward the base of the brain and the median eminence. The majority of LHRH cells are in the rostral portion of the V in preoptic and anterior hypothalamic areas. Few cells are present in the basal hypothalamus. The processes of LHRH cells form two diffuse fiber systems which are separated by the midline hypothalamic nuclei over most of their course and converge in the basal hypothalamus close to the median eminence. The more lateral fiber system forms part of the medial forebrain bundle, while the periventricular system is associated with the wall of the third ventricle. The dispersion of LHRH cells over many nuclear groups may allow for the integration of afferents from divergent regions of the neuraxis to mediate both tonic and phasic gonadotropin secretion in the rat.

Journal ArticleDOI
TL;DR: The ontogeny of the somatostatin (SRIF) neuron system in the forebrain and diencephalon of the rat was investigated by means of the indirect immunofluorescence method.
Abstract: The ontogeny of the somatostatin (SRIF) neuron system in the forebrain and diencephalon of the rat was investigated by means of the indirect immunofluorescence method. SRIF-positive cells first appear in the primordium of the hypothalamus surrounding the fasciculus mammillothalamicus of the fetus at gestational day 14 (10–12-mm embryo). At gestational days 16–17 (14–17-mm embryo), SRIF-positive cells appear in the developing piriform cortex and entopeduncular nucleus. The fetus at gestational days 18–19 (17–26-mm embryos) showed a remarkable increase in the number of SRIF-positive cells and numerous groups of such cells are detectable in various forebrain and diencephalic areas such as the hypothalamic periventricular zone, zona incerta, area lateral to the commissura posterior (ACP), area between the optic tract and capsula interna, pars retrolenticularis (AOR), n. caudatus putamen, hippocampus, somatic sensory cortex, and n. accumbens, etc. At gestational day 20, SRIF-positive cells newly appear in the septum, olfactory bulb, diagonal band of Broca, claustrum, lateral preoptic area, and lateral habenular nucleus. The majority of SRIF-positive structures found in the forebrain and diencephalon increase in number during the perinatal stage (between gestational day 21 and postnatal day 2) and more or less maintain their immunoreactivity even in adult rats. However, SRIF-positive cells located in the AOR, ACP, and lateral septal area, etc., begin to decrease in number during the perinatal stage and no or only a few SRIF-containing cells are identified in these areas of infant and adult rats.

Journal ArticleDOI
12 Nov 1982-Science
TL;DR: Old female rats with spontaneous prolactin-secreting pituitary tumors (prolactinomas) and young females with prolact inomas produced by prolonged estrogen treatment had damaged tuberoinfundibular dopaminergic neurons.
Abstract: Old female rats with spontaneous prolactin-secreting pituitary tumors (prolactinomas) and young females with prolactinomas produced by prolonged estrogen treatment had damaged tuberoinfundibular dopaminergic neurons. Since these neurons inhibit the function of pituitary prolactin-secreting cells, their destruction may lead to development of prolactinomas.

Journal ArticleDOI
01 May 1982-Peptides
TL;DR: The evidence obtained in this study suggests that beta-EP and NE stimulate food ingestion through their action on PVN opiate and alpha-noradrenergic receptors, respectively, and thatbeta-EP's action is closely related to, and in part may be dependent upon, the PVNalpha-noradsergic system for feeding control.

Journal ArticleDOI
TL;DR: The peptide (chicken LH-RH) stimulates secretion of both LH and FSH from rat anterior pituitary cells and one possible structural candidate for this peptide is [Gln 8 ]-LH-RH, which differs from mammalian LH- RH only in that one Arg residue is replaced by a Glx residue.

Journal ArticleDOI
TL;DR: Using an antiserum to synthetic ovine corticotropin-releasing factor (CRF), CRF-like immunoreactive neurons were observed in the central nervous system of normal and colchicine-treated rats.
Abstract: Using an antiserum to synthetic ovine corticotropin-releasing factor (CRF), CRF-like immunoreactive neurons were observed in the central nervous system of normal and colchicine-treated rats. CRF immunoreactivity was observed in the hypothalamus, thalamus, amygdala, cerebral cortex, midbrain, pons medulla, cerebellum and spinal cord. The significance of the extrahypothalamic distribution of CRF-like immunoreactivity is unknown.

Journal ArticleDOI
TL;DR: In anaesthetized rats the effect of two procedures was studied on antidromically identified sympathetic preganglionic neurones (SPN) in the second thoracic segment of the spinal cord: the application of iontophoresed oxytocin and vasopressin, and bipolar electrical stimulation of the paraventricular nucleus of the hypothalamus (PVN).

Journal ArticleDOI
13 Aug 1982-Science
TL;DR: When A1 noradrenergic neurons in the caudal ventrolateral medulla of rabbits are destroyed electrolytically or by local injection of the neurotoxin kainic acid, the concentration of vasopressin in plasma increases, causing hypertension.
Abstract: When A1 noradrenergic neurons in the caudal ventrolateral medulla of rabbits are destroyed electrolytically or by local injection of the neurotoxin kainic acid, the concentration of vasopressin in plasma increases, causing hypertension. The A1 neurons may tonically inhibit the activity of vasopressin-secreting neuroendocrine cells through a direct hypothalamic projection.

Journal ArticleDOI
TL;DR: The immunohistochemical distribution of bombesin-like immunoreactivity in the central nervous system of the rat was revealed using a rabbit antibody against [Glu7]bombesin using radioimmunoassay thereby enhancing the significance of histochemical controls proving that the immunore activity detected was related toBombesin but not to substance P.

Journal ArticleDOI
TL;DR: Evidence was obtained favoring the concept of heterogeneous composition of the VMN: in ovariectomized animals many cells appeared in a state of quiescence, but other neurons showed no major alterations, and the possibility that the differences observed may be consequent to changes in synaptic organization of theVMN related to its estrogen-dependent functions is discussed.

Journal ArticleDOI
TL;DR: The results indicate that morphine and the enkephalins evoke hypothalamo-pituitary-adrenocortical activity by stimulating specific receptors in the hypothalamus and raise the possibility that opioid peptides and their receptors are physiologically important in the control of the secretion of CRF.
Abstract: The influence of morphine and enkephalins on the functional activity of the hypothalamo-pituitary-adrenocortical system in the rat was studied by investigating their effects on the secretion in vivo and in vitro of corticotrophin (ACTH) by the pituitary gland and corticotrophin-releasing factor (CRF) by the hypothalamus. A single injection of morphine caused a rise followed by a fall in hypothalamic CRF content and increases in the concentrations of ACTH in the plasma and adenohypophysis. In addition, the stress-induced increments in hypothalamic CRF and pituitary and plasma ACTH were exaggerated in morphine-treated rats. The production of ACTH by pituitary segments in vitro was not affected by the addition to the incubation medium of morphine, met-enkephalin, leu-enkephalin or naloxone. However, morphine and the enkephalins stimulated the secretion of CRF by isolated hypothalami and their effects were antagonized by naloxone. The results indicate that morphine and the enkephalins evoke hypothalamo-pituitary-adrenocortical activity by stimulating specific receptors in the hypothalamus and raise the possibility that opioid peptides and their receptors are physiologically important in the control of the secretion of CRF.

Journal ArticleDOI
TL;DR: The results suggest that NA release is enhanced by immobilization in the six regions mentioned above and that response of NA neurons occurs rapidly in the hypothalamus and amygdala but is delayed in other regions.
Abstract: Male Wistar rats were stressed by immobilization from 15 to 180 min and the effect of noradrenaline (NA) and 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO 4 ) contents in eight discrete brain regions were determined. NA levels significantly decreased and MHPG-SO 4 levels increased in the hypothalamus, amygdala, thalamus, hippocampus, pons+ med.obl. and cerebral cortex. By contrast, the basal ganglia exhibited increases in NA levels and transient decreases in MHPG-SO 4 levels. The midbrain failed to show significant alterations. The most rapid and marked increase in MHPG-SO 4 level was found in the hypothalamus. When rats were exposed to stress after treatment with probenecid 400 mg/kg, the hypothalamus and amygdala showed greater accumulations of MHPG-SO 4 in the early phase of stress, while the pons+ med.obl. and basal ganglia in the later phase. The other regions showed virtually the same accumulations. These results suggest that NA release is enhanced by immobilization in the six regions mentioned above and that response of NA neurons occurs rapidly in the hypothalamus and amygdala but is delayed in other regions.