Disease relevance of Hypothalamus, Anterior

• Lesions of the anteroventral third ventricle (AV3V), an angiotensin and osmosensitive region of the anterior hypothalamus, prevent or abort hypertension in a number of rat models [1].
• However, in spinal cats the bradycardia component (induced by angiotensin at 0.097 nmol/kg pe min, i.v.) was inhibited by stimulation of the anterior hypothalamus and the inhibition was augmented by pretreatment with phentolamine (17.7 nmol) in the nucleus tractus solitarius (NTS) [2].
• The enhancement of chlorpromazine-induced hypothermia by lesions in the anterior hypothalamus [3].
• These results support the hypothesis that cyclic AMP in the anterior hypothalamus does not mediate pyrogen-induced hyperthermia in cats [4].
• Electrical lesions of the medial preoptic area/anterior hypothalamus (MPOA/AH) have been reported to enhance the display of steroid-induced lordosis in castrated male rats [5].

Psychiatry related information on Hypothalamus, Anterior

• The effect of micro-injections of dexamphetamine chloride into the neostriatum, the nucleus accumbens, the anterior hypothalamus, and the ventricular system on self-stimulation with electrodes in the ventral tegmentum was studied [6].
• L-5-Hydroxytryptophan microinjection (1-4 micrograms/0.5 microliters) in the anterior hypothalamus 72 h after para-chlorophenylalanine administration, restored both slow wave sleep and paradoxical sleep with variable latencies for each state of sleep [7].
• Thermosensitivity of neurons in the preoptic/anterior hypothalamus (POAH) was determined for behaving kangaroo rats (Dipodomys deserti) during electrophysiologically defined wakefulness, NREM sleep and REM sleep to elucidate possible neural mechanisms for previous findings of state-dependent changes in thermoregulation [8].
• In golden hamsters, microinjections of arginine vasopressin (AVP) within the anterior hypothalamus (AH) and lateral septum (LS) elicit the display of a stereotyped behavior: flank marking [9].

High impact information on Hypothalamus, Anterior

• These findings suggest that the increased endogenous ANP in the anterior hypothalamus of SHR-S may be involved in the central regulation of BP in the model [10].
• In a previous positron emission tomography study, we found that smelling AND and EST activated regions covering sexually dimorphic nuclei of the anterior hypothalamus, and that this activation was differentiated with respect to sex and compound [11].
• Approximately half of the LHRH neurons were activated in the preoptic area and anterior hypothalamus; more anteriorly positioned LHRH neurons did not express Fos, resulting in an overall stimulation of 40% of the LHRH neurons [12].
• Inhibition seemed specific for the anterior hypothalamus because pressor responses to stimulation of the ventromedial hypothalamus were the same whether or not the intracerebroventricular infusion contained hypertonic sodium chloride [13].
• Neurotoxic lesions involving the medial preoptic area (MPOA) and anterior hypothalamus (n = 5) had no significant effects on either erectile activity or sleep-wake architecture [14].

Chemical compound and disease context of Hypothalamus, Anterior

• We report here that GABA plays a dual role in the mediation of lordosis and has differential effects in the medial hypothalamus (MH) and preoptic area/anterior hypothalamus continuum (POA-AH) [15].
• Microinjected into the preoptic anterior hypothalamus (POAH), deltorphin-II (0.1-1 microg) produced an immediate dose-related hyperthermia following injection [16].
• Superfusion of the anterior hypothalamus with isoprenaline did not change the depressor response and bradycardia induced by electrical stimulation of the anterior hypothalamus [17].
• Amitriptyline (2 mg IV or 0.25 mg IVT) produced hypotension that might reflect an action of norepinephrine on the anterior hypothalamus [18].
• Trazodone (1 mg IV or 0.25 mg IVT) produced hypotension and bradycardia that is consistent with the activation of noradrenergic neurons in the anterior hypothalamus perhaps as a result of trazodone acting on presynaptic alpha 2 receptors or on presynaptic serotonin receptors to increase the release of norepinephrine [18].

Biological context of Hypothalamus, Anterior

• Also, newly synthesized 35S-Met-labeled DBH that underwent axonal transport from the LC to the anterior hypothalamus was predominantly the 73K subunit form [19].
• 2. In rabbits exposed to a thermoneutral environment, micro-injections of PGE1, into the anterior hypothalamus, intraventricular injections of PGE1, and intravenous injection so leucocyte pyrogen all caused fever accompanied by vasoconstriction in the ears and reduced respiratory rate [20].
• Changes in cellular levels of messenger ribonucleic acid encoding gonadotropin-releasing hormone in the anterior hypothalamus of female rats during the estrous cycle [21].
• In addition to Fos in GnRH-positive cells, many more non-GnRH cells in the preoptic area, anterior hypothalamus, and ventrolateral hypothalamus expressed Fos during the surge than in the luteal phase or after ovariectomy [22].
• Carbachol (0.1-2 micrograms) and noradrenaline (5-20 micrograms) injected into the anterior hypothalamus of unanaesthetized unrestrained rats evoked dose-dependent falls in heart rate and increases in arterial blood pressure [23].

Anatomical context of Hypothalamus, Anterior

• Prostaglandin E2 exerts an awaking effect in the posterior hypothalamus at a site distinct from that mediating its febrile action in the anterior hypothalamus [24].
• Lesions of the anterior hypothalamus, amygdala, and the hippocampal commissure as well as lesions with 6-hydroxydopamine and 5,7-dihydroxytryptamine failed to decrease striatal somatostatin levels [25].
• Study of the post-natal effects of chemopreventive agents on ethylnitrosourea-induced transplacental carcinogenesis in rats. II. Influence of low-molecular-weight polypeptide factors from the thymus, pineal gland, bone marrow, anterior hypothalamus, brain cortex and brain white substance [26].
• Serotonin and its major metabolite 5-hydroxyindoleacetic acid were measured in the pons-medulla, midbrain, posterior hypothalamus, anterior hypothalamus, thalamus, and cerebellum of cardiomyopathic hamsters and their age-matched controls during the early and terminal stages of the cardiomyopathy [27].
• A much smaller number was observed in the dorsomedial hypothalamic nucleus and the anterior hypothalamus, and only a very few dopamine cells could be detected in contact with beta-endorphin axons in the arcuate nucleus (particularly in the posterior part where the beta-endorphin cells are located) and the medial part of the zona incerta [28].

Associations of Hypothalamus, Anterior with chemical compounds

• Interleukin-1 beta augments release of norepinephrine, dopamine, and serotonin in the rat anterior hypothalamus [29].
• Social subjugation resulted in a 50% decrease in vasopressin levels within the anterior hypothalamus, a site involved in the regulation of aggression [30].
• Endogenous norepinephrine levels and turnover were lower in the anterior hypothalamus of SHR-S fed 8% NaCl than in those fed 1% NaCl but were not significantly different in other groups [31].
• Depressor effect of blocking angiotensin subtype 1 receptors in anterior hypothalamus [32].
• On the other hand, ethanol microinjection into the anterior hypothalamus caused a site-dependent pressor effect and an increase in sympathetic efferent discharge [33].

Gene context of Hypothalamus, Anterior

• Comparative expression studies at the anterior hypothalamus at early stages reveal that there are separate pools of Trh cells with distinctive molecular codes defined by Sim1 and Sim2 expression [34].
• These data suggest that, although Isl-1 and ERalpha can interact, they are not always found in the same cells and that regulation of ERalpha function is not under the same control in the VMH, preoptic area, and the anterior hypothalamus [35].
• We have determined that Isl-1 is localized in several regions of the hypothalamus, including the ER rich areas of the ventromedial nucleus (VMH), the preoptic area, and the anterior hypothalamus [35].
• In the present work we sought to establish the receptors and intracellular mechanisms underlying the increase in nitric oxide synthase (NOS) activity stimulated by ET-1 and ET-3 in the rat anterior hypothalamus [36].
• Endothelin 1 and 3 enhance neuronal nitric oxide synthase activity through ETB receptors involving multiple signaling pathways in the rat anterior hypothalamus [36].

Analytical, diagnostic and therapeutic context of Hypothalamus, Anterior

• Using a microdialysis method, we investigated the effects of the nipecotic acid-induced increase in content of endogenous GABA on in vivo release of histamine from the anterior hypothalamus (AHy) of urethane-anesthetized rats [37].
• In situ hybridization was performed on paraformaldehyde-fixed cryostat sections through an area extending from the preoptic area to the anterior hypothalamus using a 35S-labeled 48-base oligodeoxynucleotide complementary to the GnRH coding region of the GnRH DNA [38].
• Using immunohistochemistry for serotonin after intrahypothalamic L-5-hydroxytryptophan microinjection in parachlorophenylalanine-pretreated cat, we defined a restricted region of the anterior hypothalamus possibly responsible for the hypnogenic effect [7].
• The effects of norepinephrine microinjected into the anterior hypothalamus were examined in feline affective defense behavior elicited by electrical stimulation of the region of the ventromedial nucleus [39].
• The site of action of gonadal hormones in the regulation of hepatic steroid metabolism was investigated by measuring the effects of (i) implantation of estradiol into the pituitary gland or anterior hypothalamus of males and (ii) subcutaneous injection of a synthetic androgen in differentiated male and female rats [40].

References