Showing papers on "Hypothalamus published in 1986"
TL;DR: These findings, demonstrating that exogenous NPY is capable of overriding mechanisms of satiety and body weight control, suggest that disturbances in NPY function may play a role in some disorders of eating behavior and body Weight regulation.
882 citations
TL;DR: Anatomic and physiological studies suggest a varied, but important, function for NPY in mammalian nervous system and circulating levels of NPY may prove useful in the diagnosis of pheochromocytoma.
497 citations
TL;DR: The distribution of CRF-LI was determined in 36 rat brain regions by combined radioimmunoassay-micropunch dissection techniques and the effect of stress on CRF -LI was investigated, using a chronic stress model that induces endocrine changes in rats similar to those seen in depressed humans.
Abstract: Corticotropin releasing factor (CRF) may regulate endocrine, autonomic, and behavioral responses to stress. Evidence indicates that CRF-like immunoreactivity (CRF-LI) is widely distributed throughout the CNS. In this study, the distribution of CRF-LI was determined in 36 rat brain regions by combined radioimmunoassay-micropunch dissection techniques and the effect of stress on CRF-LI was investigated, using a chronic stress model that induces endocrine changes in rats similar to those seen in depressed humans. A control group of rats was handled daily. An acute stress group was subjected to 3 hr of immobilization at 4 degrees C, while a chronic stress group was exposed to unpredictable stressors. Thirty-six brain regions were microdissected by the technique of Palkovits and assayed for CRF-LI, using a specific antiserum to ovine CRF. CRF-LI was detected in most regions. In controls, the highest concentrations were found in the arcuate nucleus/median eminence, the hypothalamic paraventricular (PVN) nucleus, and the periventricular nucleus. The next highest levels were found in the raphe nuclei and dorsal vagal complex. CRF-LI was well represented in the locus coeruleus (LC); in the central, cortical, and medial amygdaloid nuclei; and in the bed nucleus of the stria terminalis. Low concentrations occurred in the hippocampus and cerebrocortical regions. Appreciable concentrations were detected in midbrain and brain stem regions. Acute stress reduced CRF-LI in the arcuate nucleus/median eminence (ME) (by 52%) and in the median preoptic (MPO) nucleus (by 32%) and doubled its concentration in the locus coeruleus.(ABSTRACT TRUNCATED AT 250 WORDS)
465 citations
TL;DR: A 35S-labeled 48-base synthetic oligonucleotide complementary to a portion of the rat corticotropin-releasing factor (CRF) mRNA was used for in situ hybridization histochemistry and CRF-synthesizing cells were observed in the medial parvocellular subdivision.
378 citations
TL;DR: In the rat, high levels of NGF mRNA were found in cerebral cortex, hippocampus and thalamus/hypothalamus, medium levels in striatum and brainstem, and low levels in cerebellum and spinal cord as discussed by the authors.
319 citations
TL;DR: Although pituitary corticotrophs appear to be functional at birth, exposure to stress does not elicit marked increases in plasma ACTH until day 14 of age, which suggests that endogenous CRF can be released by at least some stimuli as early as day 3.
Abstract: The neonatal rat shows a period of decreased responsiveness to noxious stimuli during the first 3 weeks of life, but the nature of this impairment is still controversial. To test the functionality of the hypothalamus-pituitary-adrenal axis during this period, we studied pituitary and adrenal responsiveness to exogenous ovine CRF and the ability of various stressors (ether vapors, electroshocks, and hypoxia) to elicit ACTH and corticosterone secretion. We also measured hypothalamic CRF content and pituitary ACTH content as well as CRF-binding sites in the anterior pituitary. From days 3–10, small elevations in plasma ACTH and corticosterone levels were observed after a 3-min exposure to ether vapors or electroshocks. In contrast, during this period, a 20- min exposure to hypoxia (5% O2 in N2) was unable to trigger measurable ACTH secretion, while corticosterone was significantly elevated. From days 14–21, plasma ACTH and corticosterone levels increased significantly after exposure to ether stress, hypoxia,...
317 citations
282 citations
TL;DR: The dorsomedial hypothalamic nucleus involvement in the control of feeding and pancreatic hormone release appears that the DMH participates in this control via descending pathways to the preganglionic pancreas innervating neurons but also via a neuroendocrine route.
265 citations
TL;DR: The luteinizing hormone‐releasing hormone (LHRH) system of the sheep brain was examined by light microscopic immunocytochemistry with thick, unembedded sections to compare the distribution and morphology of LHRH cells and their fibers in intact and ovariectomized anestrous ewes, and in breeding season eWes during the mid‐luteal phase of their estrous cycle.
Abstract: The luteinizing hormone-releasing hormone (LHRH) system of the sheep brain was examined by light microscopic immunocytochemistry with thick, unembedded sections. We compared the distribution and morphology of LHRH cells and their fibers in intact and ovariectomized anestrous ewes, and in breeding season ewes during the mid-luteal phase of their estrous cycle. In all animals, a majority of LHRH neurons were found in the medial preoptic area adjacent to the organum vasculosum of the lamina terminalis. These cells formed a continuum rostrally with immunoreactive neurons in the diagonal band of Broca and medial septum and caudally with cells in the ventrolateral anterior hypothalamus and lateral hypothalamus. Relatively few cells (1-2%) were seen in the arcuate nucleus or its vicinity. Preoptic LHRH neurons project to the tubero-infundibular sulcus of the median eminence by at least two routes: a major ventrolateral projection above the optic tract in the anterior and lateral hypothalamus, and a less prominent periventricular pathway along the third ventricle. LHRH fibers were also observed in a number of extrahypothalamic regions, including the medial amygdala and the accessory olfactory bulb. Immunoreactive LHRH neurons in the sheep exhibited a complex light microscopic morphology unlike that seen in LHRH cells of any other species to date. LHRH cells with extensive, branching processes were frequently found in clusters with close somatic appositions between neighboring cells. Multiple thin protuberances emanated from the soma of many immunoreactive neurons. Immunoreactive fibers with beaded varicosities often were intimately associated with both cell bodies and their dendritic processes. Morphometric analyses revealed that preoptic LHRH neurons in three of four mid-luteal phase ewes had a shorter total dendritic length than those neurons in either intact or ovariectomized anestrous ewes, but this difference between breeding season and anestrous ewes was not statistically significant. Evidence for possible seasonal and/or steroid-induced alterations in the morphology of LHRH neurons must be documented by further studies, including immunocytochemical observations at an ultrastructural level.
249 citations
TL;DR: It is shown, by a combined method of estrogen autoradiography and GAD immunocytochemistry, that estrogen-receptive neurons of GABAergic nature exist in the MPO/AH.
Abstract: Estrogen target neurons are numerous in the medial preoptic/anterior hypothalamic area (MPO/AH) of the female rat brain, and they are thought to play a crucial role in reproductive functions. This brain region is also known to contain high concentrations of the inhibitory transmitter gamma-aminobutyric acid (GABA) and of its synthesizing enzyme glutamate decarboxylase (GAD). Since it is known that GABA is involved in the regulation of gonadotropin release from the pituitary gland it has been proposed that estrogen feedback may be mediated by this transmitter. Here we show, by a combined method of estrogen autoradiography and GAD immunocytochemistry, that estrogen-receptive neurons of GABAergic nature exist in the MPO/AH.
243 citations
University of Cambridge1, Karolinska Institutet2, Uppsala University3, University of Liverpool4, University of Newcastle5, McGill University6, University of Minnesota7, New York University8, Rockefeller University9, Salk Institute for Biological Studies10, Stanford University11, Penn State Milton S. Hershey Medical Center12, Research Triangle Park13
TL;DR: Examination of the distribution within the arcuate nucleus of the hypothalamus of neurons containing the following immunoreactivities established numerous patterns of coexistence of these various neurotransmitters and neuropeptides.
TL;DR: The present study evaluated the distribution of possible monoaminergic and peptidergic cells and fibers within the MPN, as well as in adjacent regions of the medial preoptic area of the adult male rat.
Abstract: The medial preoptic nucleus (MPN) is a sexually dimorphic complex with three major subdivisions. The cell-dense central (MPNc) and medial (MPNm) subdivisions are larger in male rats, while the cell-sparse lateral subdivision (MPNl) occupies a majority of the nucleus in females. In the present study we evaluated the distribution of possible monoaminergic and peptidergic cells and fibers within the MPN, as well as in adjacent regions of the medial preoptic area of the adult male rat. For this, we used an indirect immunohistochemical method with antisera to serotonin (5HT), dopamine beta-hydroxylase (DBH), tyrosine hydroxylase (TH), neuropeptide Y (NPY), cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP), substance P (SP), neurotensin (NT), corticotropin-releasing factor (CRF), luteotropin-releasing hormone (LRH), somatostatin (SS), thyrotropin-releasing hormone (TRH), oxytocin (OXY), vasopressin (VAS), adrenocorticotropic hormone (1-24; ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), leucine-enkephalin (L-ENK), and calcitonin gene-related peptide (CGRP). The results suggest that cell bodies and/or fibers crossreacting with all of these putative neurotransmitters are differentially distributed within the MPN. Within the MPNm, the densest plexuses of fibers were stained with antisera to SP and NPY, while moderate densities of fibers were stained with anti-DBH, SS, CCK, CGRP, ACTH, and alpha-MSH, and only a few fibers were stained with anti-5HT, TH, NT, VAS, and L-ENK. Moderate numbers of SP- and L-ENK-immunoreactive cell bodies, and a few SS-, NT-, CRF-, and TRH-stained cell bodies were also found within the MPNm. The MPNc contained a dense plexus of CCK-immunoreactive fibers, as well as a few CRF-immunoreactive fibers. Both fiber types were localized almost exclusively to this subdivision, while most of the others studied here appeared to avoid it selectively. This suggests that there are relatively few inputs to the MPNc, and that they tend to avoid other parts of the nucleus, although moderate densities of DBH- and NPY-immunoreactive fibers were found in both the MPNm and MPNc. The MPNc contained several CCK-immunoreactive cell bodies as well as a moderate number of TRH-stained cell bodies. Both cell types were nearly completely localized to the MPNc. The major inputs to the MPNl studied here appear to be stained with antisera to 5HT and L-ENK, although moderate numbers of NT- and CRF- immunoreactive fibers were also found in this part of the nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: It is proposed that serotonin acts, in part, through a satiety mechanism of the medial hypothalamus, to reduce ingestion of carbohydrate while sparing protein intake, in controlling the ratio of carbohydrate to protein intake.
TL;DR: This chapter outlines current views about the organization of neural circuitry underlying the integration of stress responses, with special emphasis on the hypothalamic regulation of adrenocorticotropic hormone (ACTH) release from the anterior pituitary.
Abstract: Publisher Summary This chapter outlines current views about the organization of neural circuitry underlying the integration of stress responses, with special emphasis on the hypothalamic regulation of adrenocorticotropic hormone (ACTH) release from the anterior pituitary. The adrenal gland plays a major role in such responses. The release of glucocorticoid hormones from the adrenal cortex is influenced by ACTH, while the release of catecholamines from the adrenal medulla is mediated primarily by the sympathetic nervous system. The most influential unifying hypothesis in this field was advanced by Hans Selye, who proposed that most stressors induce two classes of response. One, which is called the “stress response,” is common to all stressors and involves the release of ACTH and adrenal catecholamines, which may have different time courses and lead to different functional consequences. The other consists of responses that are appropriate for individual stressors. The brain is involved in processing all the classes of stimuli that can be regarded as stressors and is responsible for coordinating the groups of appropriate autonomic, endocrine, and behavioral responses. Recent anatomical and physiological evidence is beginning to clarify the organization of specific neural circuits mediating adrenal steroid and catecholamine release during the stress response, as well as the other endocrine, autonomic, and behavioral responses specific to hypovolemia. The paraventricular nucleus of the hypothalamus (PVH) in this circuitry regulates ACTH release from the anterior pituitary; it also plays an important role in the secretion of vasopressin from the posterior pituitary, and modulates baroreceptor reflexes.
TL;DR: Results support the utility of in situ hybridization techniques for elucidating physiological influences on regional peptidergic function, and are consistent with a prominent role for vasopressinergic suprachiasmatic neurons in generating the cerebrospinal fluid vasoppressin rhythm.
Abstract: In situ hybridization of an oligonucleotide probe complementary to vasopressin messenger RNA (mRNA) in sections from normal or Brattleboro rat hypothalami revealed hybridization densities in each of three vasopressin-rich nuclei: the supraoptic, paraventricular, and suprachiasmatic. When entrained to a daily light-dark cycle, each rat strain displayed diurnal variation in hybridizable mRNA in the suprachiasmatic, but not in the supraoptic or paraventricular nuclei. The higher values for suprachiasmatic mRNA in the morning correlate well with previously elucidated morning increases in vasopressin immunoreactivity in the cerebrospinal fluid. These results support the utility of in situ hybridization techniques for elucidating physiological influences on regional peptidergic function, are consistent with a prominent role for vasopressinergic suprachiasmatic neurons in generating the cerebrospinal fluid vasopressin rhythm, and suggest that regulation of this mRNA rhythm is not dependent on release of intact peptide.
TL;DR: Dispersed anterior pituitary cells harvested from lactating female rats and OVX estrogen-primed rats released PRL in a specific, significant, and dose-related fashion when perifused in vitro with incubation medium containing 10(-7)-10(-9) M OT, doses similar to levels found previously in hypophysial portal plasma.
Abstract: The presence of oxytocin (OT) in neuronal elements of the external layer of the median eminence and in hypophysial portal plasma suggests a role for the peptide in the control of anterior pituitary function. We have reported previously that OT stimulates PRL release in vitro; therefore, we attempted to establish evidence for a physiological PRL-releasing role for OT. Plasma OT levels rose significantly just before the PRL surges occurring during a suckling stimulus in lactating rats (10 min after pup reinstatement vs. 15 min for PRL) and 48 h after estrogen injection in ovariectomized (OVX) rats (at 1200 h vs. 1300 h). Dispersed anterior pituitary cells harvested from lactating female rats and OVX estrogen-primed rats released PRL in a specific, significant, and dose-related fashion when perifused in vitro with incubation medium containing 10−7–10−9 m OT, doses similar to levels found previously in hypophysial portal plasma. Infusion of antiserum specific for OT into lactating females before pup reinstate...
Book•
14 Oct 1986
TL;DR: This paper presents an overview of the Organization of the Hypothalamus and development of the Specialized Linings of the Third Ventricle Neuroepithelium, as well as some Glial Components of theHypothalamus.
Abstract: 1 Introduction.- 2 Materials and Methods.- 3 An Overview of the Organization of the Hypothalamus.- 4 Delineation of the Hypothalamic Primordium of the Third Ventricle Neuroepithelium.- 5 Development of the Reticular Hypothalamus: The First Wave.- 5.1 The Lateral Hypothalamus.- 5.2 The Entopeduncular Nucleus.- 5.3 The Zona Incerta.- 6 Development of the Core Hypothalamus: The Second Wave.- 6.1 Development of the Preoptic Area.- 6.2 Development of the Anterior Hypothalamus: Rostral Region.- 6.2.1 The Anterior Hypothalamic Nuclei.- 6.2.2 The Paraventricular Nucleus.- 6.2.3 The Supraoptic Nucleus.- 6.2.4 The Problem of the Bed Nucleus of the Stria Terminalis.- 6.3 Development of the Anterior Hypothalamus: Caudal Region.- 6.3.1 The Ventromedial Nucleus.- 6.3.2 The Dorsomedial Nucleus.- 6.4 Development of the Posterior Hypothalamus: Ventral Region.- 6.4.1 The Subthalamic Nucleus.- 6.4.2 The Tuberal Magnocellular Nucleus.- 6.4.3 The Premammillary Nuclei.- 6.5 Development of the Posterior Hypothalamus: Dorsal Region.- 6.5.1 The Supramammillary Nucleus.- 6.5.2 The Posterior Area Nuclei.- 6.6 Development of the Mammillary Body.- 7 Development of the Midline Hypothalamus: The Third Wave.- 7.1 The Suprachiasmatic Nucleus.- 7.2 The Arcuate Nucleus.- 7.3 The Periventricular Field.- 8 Development of the Specialized Linings of the Third Ventricle.- 9 Development of Some Glial Components of the Hypothalamus.- 10 General Discussion.- 11 Summary.- References.
TL;DR: The failure of galanin to alter GH release from dispersed, cultured anterior pituitary cells in vitro further suggests that endogenous Galanin plays a neuromodulatory role at the level of the median eminence, possibly affecting the release of known GH-releasing and/or inhibiting factors.
TL;DR: The involvement of AVP and OT in the control of ACTH secretion may have important implications for physiological and pathological conditions associated with activation of the hypothalamo--hypophysial--adrenal cortical axis.
TL;DR: Stimulation using implanted electrodes in conscious rats elicited typical 'flight' and 'escape' behaviour: thus, the localized regions from which the visceral alerting response is elicited contain neurones or nerve fibres integrating the whole defence-alerting response in the rat, as in other species.
Abstract: Electrical stimulation has been employed to map areas of the rat's brain from which the cardiovascular and behavioural components of the defence reaction are elicited and hence to identify the defence areas in this species. In the anaesthetized rat, the cardiovascular pattern of response includes increases in arterial blood pressure and heart-rate, an atropine-resistant vasodilatation in the hind-limb skeletal muscle, with renal and splanchnic vasoconstriction. This was elicited from comparatively well localized areas, not confined to any particular nuclei. Responses were evoked from the rostro-caudal extent of the hypothalamus but most consistently from a region ventral to the fornix. In the midbrain, responsive sites were localized to the dorsal half of the central grey matter, the tegmentum ventro-lateral to it and a ventro-medial region which continued into the pons. Stimulation using implanted electrodes in conscious rats, within the hypothalamic and midbrain areas described above, elicited typical ‘flight’ and ‘escape’ behaviour: thus, the localized regions from which the visceral alerting response is elicited contain neurones or nerve fibres integrating the whole defence-alerting response in the rat, as in other species.
TL;DR: It is proposed that the incapacity of the female hypothalamus to produce behaviorally active E2 contributes to female quail's insensitivity to testosterone.
TL;DR: In vitro autoradiography and computer video densitometry were used to localize and quantify binding of 125I-insulin in the hypothalamus of the rat brain, consistent with the hypothesis that insulin modulates the neural regulation of feeding by acting at sites in theothalamus.
TL;DR: The most prominent collection of APir perikarya was found in the hypothalamus, adjacent to the anteroventral tip of the third ventricle, and APir neurons were observed in the pedunculopontine and laterodorsal tegmental nuclei, as well as in the ventral te segmental area.
Abstract: The atrial natriuretic peptide, atriopeptin, is a circulating hormone that plays an important role in the regulation of fluid and electrolyte homeostasis. Several recent studies have shown that atriopeptin-like immunoreactivity is present within the central nervous system as well as peripheral tissues. In the present report, we describe in detail the organization of atriopeptin-like immunoreactive (APir) perikarya and fibers in the central nervous system of the rat. The most prominent collection of APir perikarya was found in the hypothalamus, adjacent to the anteroventral tip of the third ventricle. Additional groups of APir perikarya were observed along the wall of the third ventricle and in the paraventricular and arcuate nuclei. Separate, smaller groups with distinctive morphology were seen in the lateral hypothalamic area, in the supra-mammillary, medial, and lateral mammillary nuclei, medial habenular nucleus, bed nucleus of the stria terminalis, and the central nucleus of the amygdala. In the pons and brainstem, APir neurons were observed in the pedunculopontine and laterodorsal tegmental nuclei, as well as in the ventral tegmental area, Barrington's nucleus, the parabranchial nucleus, and the nucleus of the solitary tract. The densest terminal fields of APir fibers were found in the paraventricular nucleus of the hypothalamus, the bed nucleus of the stria terminalis, the median eminence, and the interpeduncular nucleus.
The presence of atriopeptin immunoreactivity within the central nervous system suggests that atriopeptin may function as a central neuromediator. Potential functions of this candidate neuromediator deduced from its anatomical distribution are discussed, including the possibility that atriopeptin may function as both a central neuromediator and a systemic hormone in the regulation of the cardiovascular system.
TL;DR: The results provide further support for a neurotransmitter role of central NO in the control of penile erection and yawning.
TL;DR: The present result with previous electrophysiological observations strongly suggest that glutamate and/or aspartate are included in this retinohypothalamic termination, while GABA is included in intrinsic and/ or extrinsic neurons of the SCN, excluding the terminal of the retinodiazepine fibers.
TL;DR: Antisera specific for gamma-aminobutyric acid or its biosynthetic enzyme, glutamate decarboxylase, were used in pre- and postembedding immunocytochemical techniques to visualize the GABAergic innervation of the hypothalamic supraoptic nucleus, enabling evaluation of the contribution of the innervation onto each type of neuron in this nucleus.
TL;DR: It is clear that the plastic changes in the supraoptic nucleus are closely related to the activity of its oxytocinergic neurones, and these structural modifications may serve to facilitate and maintain the characteristic synchronized electrical activity of these neurones at milk ejection.
TL;DR: The results suggest that the synaptic organization in the VMN is sexually dimorphic but the occurrence of this structural difference is limited to the VL-VMN which is abundant in sex steroid receptors, and is modified by neonatal sex steroid environment.
Abstract: The ventromedial nucleus of the hypothalamus (VMN) of male and female rats was examined ultrastructurally at 100 days of age. Axodendritic shaft and spine synapses were counted in two subdivisions of the nucleus, the dorsomedial part (DM-VMN), which contains only a few sex steroid-concentrating neurons, and the ventrolateral part (VL-VMN), which is abundant in such neurons. In normal males, the numbers of shaft and spine synapses were significantly greater in the VL-VMN than in the DM-VMN. In normal females, however, there was no significant difference in the numbers of shaft and spine synapses between the DM-VMN and the VL-VMN. Moreover, the numbers of shaft and spine synapses in the VL-VMN were significantly greater in normal males than in normal females. Castration of males on day 1 significantly reduced the numbers of shaft and spine synapses in the VL-VMN to the level comparable to those of normal females. In contrast, neonatal treatment of females with 1.25 mg testosterone propionate (TP) on day 5 significantly increased the numbers of shaft and spine synapses to the levels comparable to those of normal males. In the DM-VMN, there were no significant differences in the numbers of shaft and spine synapses among normal and experimental animals. These results suggest that the synaptic organization in the VMN is sexually dimorphic but the occurrence of this structural difference is limited to the VL-VMN which is abundant in sex steroid receptors, and is modified by neonatal sex steroid environment.
TL;DR: The anatomical localization of angiotensin II receptor populations has revealed several areas of the brain where the effects of this peptide have not been investigated, suggesting a broader role for the central renin-angiotens in system in modulating several types of sensory input.
TL;DR: The distribution of immunoreactive Gn-RH in the brain of goldfish using antibodies against synthetic teleost peptide is reported and it is demonstrated that most of the fibers detected in the pituitary originate from the preoptic region.
Abstract: The organization of Gn-RH systems in the brain of teleosts has been investigated previously by immunohistochemistry using antibodies against the mammalian decapeptide which differs from the teleostean factor. Here, we report the distribution of immunoreactive Gn-RH in the brain of goldfish using antibodies against synthetic teleost peptide. Immunoreactive structures are found along a column extending from the rostral olfactory bulbs to the pituitary stalk. Cell bodies are observed within the olfactory nerves and bulbs, along the ventromedial telencephalon, the ventrolateral preoptic area and the latero-basal hypothalamus. Large perikarya are detected in the dorsal midbrain tegmentum, immediately caudal to the posterior commissure. A prominent pathway was traced from the cells located in the olfactory nerves through the medial olfactory tract and along all the perikarya described above to the pituitary stalk. In the pituitary, projections are restricted to the proximal pars distalis. A second immunoreactive pathway ascends more dorsally in the telencephalon and arches to the periventricular regions of the diencephalon. Part of this pathway forms a periventricular network in the dorsal and posterior hypothalamus, whereas other projections continue caudally to the medulla oblongata and the spinal cord. Lesions of the ventral preoptic area demonstrate that most of the fibers detected in the pituitary originate from the preoptic region.