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Query: UNIPROT:P01178 (
oxytocin
)
15,767
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Melanin-concentrating hormone
(
MCH
) is a cyclic peptide originally isolated from chum salmon pituitaries, then structurally characterized from rat hypothalami. In the fish,
MCH
induces melanin concentration within the melanophores and may inhibit ACTH secretion in vitro and under stressful conditions in vivo. In the rat,
MCH
modulates ACTH release in vivo and
oxytocin
secretion in vitro. However, on the basis of neuroanatomical features, that is, cell bodies almost exclusively confined to the lateral area of the hypothalamus and the zona incerta, while fibers are observed throughout whole rat or human brains, this peptide appears to participate as a neurotransmitter/neuromodulator in the control of goal-oriented behaviors and/or general arousal in mammals. The knowledge of structural and regulatory features of the
MCH
precursor, mRNA, and genes at the cellular and molecular levels has recently made great progress. (1) The cells expressing
MCH
and associated peptides have been defined conjointly using radioimmunoassay, immunocytochemistry, and in vitro and in vivo molecular hybridization techniques. (2) The organization of the precursor deduced from cDNA cloning has been established and led to the discovery of two novel putative peptides named
NEI
and
NGE
. (3) The regulation of
MCH
mRNA and peptide production has been explored during the course of development in rodent and human and under a variety of paradigms (neurogenic or osmotic stress, hormonal stimuli, etc.). (4) The structure of the
MCH
genes has been determined in salmon, rat, mouse, and human and revealed striking exon-intron organization differences between fish and mammals. Strong homology, with a likely functional implication, was found between salmon
MCH
mRNA and 7SL RNA, a structural RNA involved in protein translocation. Furthermore, a variant gene that may encode slightly different
MCH
was found exclusively in primates. (5) Chromosomal assignment of the authentic and variant
MCH
genes in rat and human indicates that these genes may be good candidates involved in neurodegenerative or psychiatric disorders. Based on the framework of these studies, a working model of
MCH
regulation/function in mammalian brain is finally proposed.
...
PMID:The melanin-concentrating hormone: from the peptide to the gene. 785 Aug 73
The adipose tissue-derived hormone leptin regulates body weight homeostasis by decreasing food intake and increasing energy expenditure. The weight-reducing action of leptin is thought to be mediated primarily by signal transduction through the leptin receptor (LR) in the hypothalamus. We have used immunohistochemistry to localize LR-immunoreactive (LR-IR) cells in the rat brain using an antiserum against a portion of the intracellular domain of LR that is common to all LR isoforms. The antiserum recognized the short and long isoforms of LR in transfected hematopoietic BaF3 cells. To examine the chemical nature of target cells for leptin, direct double-labeling immunofluorescence histochemistry was applied. The results show extensive distribution of LR-like immunoreactivity (LR-LI) in the brain with positively stained cells present, e.g., in the choroid plexus, cerebral cortex, hippocampus, thalamus, and hypothalamus. In the hypothalamus, strongly LR-IR neurons were present in the supraoptic nucleus (SON) and paraventricular nucleus (PVN), periventricular nucleus, arcuate nucleus, and lateral hypothalamus. Weaker LR-IR neurons were also demonstrated in the lateral and medial preoptic nuclei, suprachiasmatic nucleus, ventromedial and dorsomedial nuclei, and tuberomammillary nucleus. Confocal laser scanning microscopy showed LR-LI in the periphery of individual cells. In magnocellular neurons of the SON and PVN, LR-LI was demonstrated in vasopressin- and
oxytocin
-containing neurons. In parvocellular neurons of the PVN, LR-LI was demonstrated in many corticotropin-releasing hormone-containing neurons. LR-IR neurons were mainly seen in the ventromedial aspect of the arcuate nucleus, where LR-LI co-localized with neuropeptide Y. In the ventrolateral part of the arcuate nucleus, LR-LI was present in many large adrenocorticotropic hormone-IR proopiomelanocortin-containing neurons and in a few galanin-, neurotensin-, and growth hormone-releasing hormone-containing neurons. In the dorsomedial arcuate nucleus, few tyrosine hydroxylase (dopamine)-containing neurons were seen to have LR-LI.
Melanin-concentrating hormone
-containing neurons in the lateral hypothalamus had LR-LI. Based on the immunohistochemical results, possible interactions of leptin with brain mechanisms are discussed.
...
PMID:Leptin receptor immunoreactivity in chemically defined target neurons of the hypothalamus. 941 31
Distinct brain peptidergic circuits govern peripheral energy homeostasis and related behavior. Here we report that mitochondrial uncoupling protein 2 (UCP2) is expressed discretely in neurons involved in homeostatic regulation. UCP2 protein was associated with the mitochondria of neurons, predominantly in axons and axon terminals. UCP2-producing neurons were found to be the targets of peripheral hormones, including leptin and gonadal steroids, and the presence of UCP2 protein in axonal processes predicted increased local brain mitochondrial uncoupling activity and heat production. In the hypothalamus, perikarya producing corticotropin-releasing factor, vasopressin,
oxytocin
, and neuropeptide Y also expressed UCP2. Furthermore, axon terminals containing UCP2 innervated diverse hypothalamic neuronal populations. These cells included those producing orexin,
melanin-concentrating hormone
, and luteinizing hormone-releasing hormone. When c-fos-expressing cells were analyzed in the basal brain after either fasting or cold exposure, it was found that all activated neurons received a robust UCP2 input on their perikarya and proximal dendrites. Thus, our data suggest the novel concept that heat produced by axonal UCP2 modulates neurotransmission in homeostatic centers, thereby coordinating the activity of those brain circuits that regulate daily energy balance and related autonomic and endocrine processes.
...
PMID:Brain uncoupling protein 2: uncoupled neuronal mitochondria predict thermal synapses in homeostatic centers. 1057 39
To reveal brain regions and transmitter systems involved in control of pancreatic hormone secretion, specific vagal and sympathetic denervation were combined with injection of a retrograde transsynaptic tracer, pseudorabies virus (PRV), into the pancreas. After sympathetic or vagal transsection first-order neurons were revealed in the dorsal motor nucleus of the vagus (DMV) or in preganglionic spinal cord neurons (SPN), respectively. Careful timing of the survival of the animals allowed the detection of cell groups in immediate control of these DMV or SPN neurons. A far larger number of cell groups is involved in the control of DMV than of SPN neurons. Examples are given of a high level of interaction between the sympathetic and parasympathetic nervous system. Several cell groups project to both branches of the autonomic nervous system, sometimes even the same neurotransmitter is used, e.g.,
oxytocin
neurons in the paraventricular nucleus and
melanin-concentrating hormone
and orexin neurons in the lateral hypothalamus project to both the DMV and SPN neurons. Moreover, the appearance of third-order neurons located in the sympathetic SPN after complete sympathectomy and in the DMV after complete vagotomy illustrates the possibility that motor neurons of the sympathetic and parasympathetic system may exchange information by means of interneurons. The presence of second-order neurons in prefrontal, gustatory, and piriform cortex may provide an anatomic basis for the involvement of these cortices in the cephalic insulin response. The observation that second-order neurons in both vagal and sympathetic control of the pancreas contain neuropeptides that are known to play a role in food intake indicates a direct association between behavioral and autonomic functions. Finally, the observation of third-order neurons in the suprachiasmatic nucleus and ventromedial hypothalamus shows the modulatory action of the time of the day and metabolic state, respectively.
...
PMID:Parasympathetic and sympathetic control of the pancreas: a role for the suprachiasmatic nucleus and other hypothalamic centers that are involved in the regulation of food intake. 1122 11
The neuropeptides orexin-A and orexin-B are produced in neurons of the lateral hypothalamic area and have been implicated to be involved in the regulation of food/water intake and sleep-wake control. The orexins act at two different G-protein-coupled orexin receptors (OX-R1 and OX-R2) that are derived from separate genes and expressed differentially throughout the central nervous system. In the present study, we have used a polyclonal antipeptide antiserum to analyse in detail the distribution of OX-R1-immunoreactive neurons in the rat hypothalamus. In order to identify the chemical mediators of orexin action in the hypothalamus, the OX-R1-containing neurons were characterized with regard to the content of peptides shown previously to affect ingestive and drinking behaviour. Neurons containing OX-R1 immunoreactivity were widely distributed in the hypothalamus with cell bodies located in the suprachiasmatic, periventricular, paraventricular (both magno- and parvocellular division), supraoptic, arcuate, ventromedial, dorsomedial and tuberomammillary nuclei and the lateral hypothalamic area. In magnocellular neurons of the paraventricular and supraoptic nuclei, OX-R1 immunoreactivity was seen in both vasopressin- and
oxytocin
-containing neurons. OX-R1 immunoreactivity was demonstrated in vasopressin and vasoactive intestinal polypeptide (VIP) neurons of the suprachiasmatic nucleus, in somatostatin neurons of the periventricular nucleus and in corticotropin-releasing hormone (CRH) neurons of the parvocellular paraventricular nucleus. In the arcuate nucleus, OX-R1 immunoreactivity was present in neuropeptide Y (NPY) and agouti-related peptide (AGRP) neurons of the ventromedial part as well as in proopiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) neurons of the ventrolateral division. In the lateral hypothalamic area, OX-R1 immunoreactivity was demonstrated in
melanin-concentrating hormone
(
MCH
)- and orexin-containing neurons. In the hypothalamic tuberomammillary nucleus, OX-R1-immunoreactivity was shown in many histamine-containing neurons. The results support the idea that orexins have important actions on hypothalamic neurons that control food intake and fluid balance, but also that orexins may regulate other neuroendocrine systems.
...
PMID:Orexin receptor-1 (OX-R1) immunoreactivity in chemically identified neurons of the hypothalamus: focus on orexin targets involved in control of food and water intake. 1184 98
Agouti-related protein (AgRP) is coexpressed with neuropeptide Y (NPY) in a population of neurons in the arcuate nucleus (ARC) of the hypothalamus and stimulates food intake for up to 7 days if injected intracerebroventricularly. The prolonged food intake stimulation does not seem to depend on continued competition at the melanocortin-4 receptor (MC4R), because the relatively specific MC4R agonist MTII regains its ability to suppress food intake 24 h after AgRP injection. Intracerebroventricular AgRP also stimulates c-Fos expression 24 h after injection in several brain areas, so the neurons exhibiting delayed Fos expression might be particularly important in feeding behavior. Thus we aimed to identify the neurochemical phenotype of some of these neurons in select hypothalamic areas, using double-label immunohistochemistry. AgRP-injected rats ingested significantly more chow (10.2 +/- 0.6 g) vs. saline controls (3.4 +/- 0.7 g) in the first 9 h (light phase) after injection. In the lateral hypothalamus (particularly the perifornical area) 23 h after injection, AgRP induced significantly more Fos vs. saline in orexin-A (OXA) neurons (25.6 +/- 4.9 vs. 4.8 +/- 3.1%), but not in
melanin-concentrating hormone
(
MCH
) or cocaine- and amphetamine-regulated transcript (CART) neurons. In the ARC, AgRP induced significantly more Fos in CART (40.6 +/- 5.9 vs. 13.4 +/- 1.8%) but not NPY neurons. In the paraventricular nucleus, there was no significant difference in Fos expression induced by AgRP vs. saline in
oxytocin
and CART neurons. We conclude that the long-lasting hyperphagia induced by AgRP is correlated with and possibly partially mediated by hyperactive OXA neurons in the lateral hypothalamus and CART neurons in the ARC, but not by NPY and
MCH
neurons. The substantial increase in light-phase food intake by AgRP supports a role for the arousing effects of OXA. Activation of CART neurons in the ARC (which likely coexpress proopiomelanocortin) could indicate attempts to activate counterregulatory decreases in food intake.
...
PMID:Neurochemical phenotype of hypothalamic neurons showing Fos expression 23 h after intracranial AgRP. 1201 Jul 60
Dual-labeling immunohistochemical or in situ hybridization studies for the recently cloned epsilon-subunit and several neuropeptides were performed in the rat hypothalamus. We revealed an extensive co-expression (>90%) with hypocretin (Hcrt),
oxytocin
(OT), the gonadotropin-releasing hormone (GnRH), and the
melanin-concentrating hormone
(
MCH
) peptides, whereas occasional co-expression (<10%) with cocaine-amphetamine-regulated transcript (CART) was found. Our results suggest that novel GABA(A) receptor subtypes comprising epsilon-subunit are important for metabolic and neuroendocrine functions.
...
PMID:GABAA receptor epsilon subunit expression in identified peptidergic neurons of the rat hypothalamus. 1265 Sep 90
Corticolimbic circuits involving the prefrontal cortex, amygdala, and ventral striatum determine the reward value of food and might play a role in environmentally induced obesity. Chemical manipulation of the nucleus accumbens shell (AcbSh) has been shown to elicit robust feeding and Fos expression in the hypothalamus and other brain areas of satiated rats. To determine the neurochemical phenotype of hypothalamic neurons receiving input from the AcbSh, we carried out c-Fos/peptide double-labeling immunohistochemistry in various hypothalamic areas known to contain feeding peptides, from rats that exhibited a significant feeding response after AcbSh microinjection of the GABA(A) agonist muscimol. In the perifornical area, a significantly higher percentage of orexin neurons expressed Fos after muscimol compared with saline injection. In contrast, Fos expression was not induced in
melanin-concentrating hormone
and cocaine-amphetamine-related transcript (CART) neurons. In the arcuate nucleus, Fos activation was significantly lower in neurons coexpressing CART and proopiomelanocortin, and there was a tendency for higher Fos expression in neuropeptide Y neurons. In the paraventricular nucleus, no significant activation of
oxytocin
and CART neurons was found. Thus AcbSh manipulation may elicit food intake through coordinated stimulation of hypothalamic neurons expressing orexigenic peptides and suppression of neurons expressing anorexigenic peptides. However, activation of many neurons not expressing these peptides suggests that additional peptides/transmitters in the lateral hypothalamus and accumbens projections to other brain areas might also be involved.
...
PMID:Peptides that regulate food intake: appetite-inducing accumbens manipulation activates hypothalamic orexin neurons and inhibits POMC neurons. 1273 70
The neuropeptides, as well as their respective receptors, are widely distributed throughout the mammalian central nervous system. During learning and memory processes, besides structural synaptic remodeling, changes are observed at molecular and metabolic levels with the alterations in neurotransmitter and neuropeptide synthesis and release. While there is consensus that brain cholinergic neurotransmission plays a critical role in the processes related to learning and memory, it is also well known that these functions are influenced by a tremendous number of neuropeptides and non-peptide molecules. Arginine vasopressin (AVP),
oxytocin
, angiotensin II, insulin, growth factors, serotonin (5-HT),
melanin concentrating hormone
, histamine, bombesin and gastrin-releasing peptide (GRP), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), dopamine, corticotropin releasing factor (CRF) have modulatory effects on learning and memory. Among these peptides CCK, 5-HT and CRF play strategic roles in the modulation of memory processes under stressful conditions. CRF is accepted as the main neuropeptide involved in both physical and emotional stress, with a protective role during stress, possibly through the activation of the hypothalamo-pitiuitary (HPA) axis. The peptide CCK has been proposed to facilitate memory processing and CCK-like immunoreactivity in the hypothalamus was observed upon stress exposure, suggesting that CCK may participate in the central control of stress response and stress-induced memory dysfunction. On the other hand, 5-HT appears to play a role in behaviors that involve a high cognitive demand and stress exposure activates serotonergic systems in a variety of brain regions. The physiological role and therapeutic efficacy of various neuropeptides and the impact of stress exposure in the acquisition and consolidation of memory will be reviewed thoroughly.
...
PMID:The physiology of learning and memory: role of peptides and stress. 1558 16
Nesfatin-1 is a recently identified satiety molecule detectable in neurons of the hypothalamus and nucleus of solitary tract (NTS). Immunohistochemical studies revealed nesfatin-1-immunoreactive (irNEF) cells in the Edinger-Westphal nucleus, dorsal motor nucleus of vagus, and caudal raphe nuclei of the rats, in addition to the hypothalamus and NTS reported in the initial study. Double-labeling immunohistochemistry showed that irNEF cells were vasopressin or
oxytocin
positive in the paraventricular and supraoptic nucleus; cocaine-amphetamine-regulated transcript or tyrosine hydroxylase positive in arcuate nucleus; cocaine-amphetamine-regulated transcript or
melanin concentrating hormone
positive in the lateral hypothalamus. In the brainstem, irNEF neurons were choline acetyltransferase positive in the Edinger-Westphal nucleus and dorsal motor nucleus of vagus; tyrosine hydroxylase positive in the NTS; and 5-hydroxytryptamine positive in the caudal raphe nucleus. The biological activity of rat nesfatin-1 (1-82) (100 nm) was assessed by the Ca(2+) microfluorometric method. Nesfatin-1 elevated intracellular Ca(2+) concentrations [Ca(2+)](i) in dissociated and cultured hypothalamic neurons. The response was prevented by pretreating the cells with pertussis toxin (100 nm) or Ca(2+)-free solution and by a combination of the L-type and P/Q-type calcium channel blocker verapamil (1 microm) and omega-conotoxin MVIIC (100 nm). The protein kinase A inhibitor KT 5720 (1 microm) suppressed nesfatin-1-induced rise in [Ca(2+)](i). The result shows that irNEF is distributed to several discrete nuclei in the brainstem, in addition to the hypothalamus and NTS reported earlier, and that the peptide interacts with a G protein-coupled receptor, leading to an increase of [Ca(2+)](i), which is linked to protein kinase A activation in cultured rat hypothalamic neurons.
...
PMID:Nesfatin-1: distribution and interaction with a G protein-coupled receptor in the rat brain. 1762 99
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