Electrophysiologic determination of projections from ventromedial hypothalamus to midbrain central gray: differences between female and male rats

1981 ◽  
Vol 225 (1) ◽  
pp. 184-188 ◽  
Author(s):  
Yasuo Sakuma ◽  
Donald Pfaff
Keyword(s):  
Ventromedial Hypothalamus ◽  
Male Rats ◽  
Central Gray

scholarly journals Role of Ventromedial Hypothalamus in Sucrose-Induced Obesity on Metabolic Parameters

2021 ◽  
pp. 097275312110057
Author(s):  
Archana Gaur ◽  
G.K. Pal ◽  
Pravati Pal
Keyword(s):  
Insulin Resistance ◽  
Weight Gain ◽  
Food Intake ◽  
Ventromedial Hypothalamus ◽  
Female Rats ◽  
Metabolic Parameters ◽  
Male Rats ◽  
Significant Weight Gain ◽  
The Metabolic Syndrome

Background: Obesity is because of excessive fat accumulation that affects health adversely in the form of various diseases such as diabetes, hypertension, cardiovascular diseases, and many other disorders. Our Indian diet is rich in carbohydrates, and hence the sucrose-induced obesity is an apt model to mimic this. Ventromedial hypothalamus (VMH) is linked to the regulation of food intake in animals as well as humans. Purpose: To understand the role of VMHin sucrose-induced obesity on metabolic parameters. Methods: A total of 24 adult rats were made obese by feeding them on a 32% sucrose solution for 10 weeks. The VMH nucleus was ablated in the experimental group and sham lesions were made in the control group. Food intake, body weight, and biochemical parameters were compared before and after the lesion. Results: Male rats had a significant weight gain along with hyperphagia, whereas female rats did not have a significant weight gain inspite of hyperphagia. Insulin resistance and dyslipidemia were seen in both the experimental and control groups. Conclusion: A sucrose diet produces obesity which is similar to the metabolic syndrome with insulin resistance and dyslipidemia, and a VMH lesion further exaggerates it. Males are more prone to this exaggeration.

Responses to catecholamines in perfused livers of hypothalamic-lesioned rats

1993 ◽  
Vol 265 (1) ◽  
pp. R117-R123
Author(s):  
Y. Matsui ◽  
H. Ishibashi ◽  
K. Kimura ◽  
M. Shiota ◽  
M. Ohta ◽  
...  
Keyword(s):  
High Performance ◽  
Glucose Production ◽  
Ventromedial Hypothalamus ◽  
Plasma Corticosterone ◽  
Beta Agonist ◽  
Male Rats ◽  
Plasma Epinephrine ◽  
Chromatography Analysis ◽  
And Control ◽  
Alpha Agonist

The responses of hepatic glycogenolysis to catecholamines in ventromedial hypothalamus (VMH)-lesioned male rats were examined in perfused livers. Seven days after bilateral electrical lesioning of the VMH, the livers were perfused. Isoproterenol, a beta-agonist, stimulated greater glucose production in VMH-lesioned rats than in controls (32.8 vs. 5.6 mumol glucose.h-1.g liver-1), while responses to phenylephrine, an alpha-agonist, decreased significantly compared with controls (44.4 vs. 69.8 mumol glucose.h-1.g liver-1). There were no significant differences in responses of livers to glucagon and vasopressin between control and VMH-lesioned rats. Adrenodemedullation showed the same effect on beta-responses as lesions in the VMH, but no effect on alpha-responses. Plasma epinephrine levels were not detectable with the high-performance liquid chromatography analysis in VMH-lesioned rats. The periodicity of plasma corticosterone levels was observed in both VMH-lesioned and control rats, although daytime increases in plasma corticosterone were blocked by VMH lesions. These results suggest that the lesions in the VMH cause changes in the levels of adrenergic receptor and that the increase in beta-responses is caused mostly by the reduction of plasma epinephrine.

Connections between the pontine central gray and the ventromedial hypothalamus are essential for lordosis in female rats.

1990 ◽  
Vol 104 (3) ◽  
pp. 477-488 ◽  
Author(s):  
Ann C. Hennessey ◽  
Lael Camak ◽  
Frank Gordon ◽  
David A. Edwards
Keyword(s):  
Ventromedial Hypothalamus ◽  
Female Rats ◽  
Central Gray

scholarly journals Rapid and Widespread Effects of 17β-Estradiol on Intracellular Signaling in the Male Songbird Brain: A Seasonal Comparison

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1364-1376 ◽  
Author(s):  
Sarah A. Heimovics ◽  
Nora H. Prior ◽  
Chris J. Maddison ◽  
Kiran K. Soma
Keyword(s):  
Breeding Season ◽  
Intracellular Signaling ◽  
Ventromedial Hypothalamus ◽  
Brain Regions ◽  
Camp Response Element Binding ◽  
Nonbreeding Season ◽  
Multiple Regions ◽  
17Β Estradiol ◽  
Caudomedial Nidopallium ◽  
Central Gray

Across vertebrate species, 17β-estradiol (E2) acts on the brain via both genomic and nongenomic mechanisms to influence neuronal physiology and behavior. Nongenomic E2 signaling is typically initiated by membrane-associated estrogen receptors that modulate intracellular signaling cascades, including rapid phosphorylation of ERK. Phosphorylated ERK (pERK) can, in turn, rapidly phosphorylate tyrosine hydroxylase (TH) and cAMP response element-binding protein (CREB). Recent data suggest that the rapid effects of E2 on mouse aggressive behavior are more prominent during short photoperiods (winter) and that acute aromatase inhibition reduces songbird aggression in winter only. To date, seasonal plasticity in the rapid effects of E2 on intracellular signaling has not been investigated. Here, we compared the effects of acute (15 min) E2 treatment on pERK, pTH, and pCREB immunoreactivity in male song sparrows (Melospiza melodia) pretreated with the aromatase inhibitor fadrozole during the breeding and nonbreeding seasons. We examined immunoreactivity in 14 brain regions including portions of the song control system, social behavior network, and the hippocampus (Hp). In both seasons, E2 significantly decreased pERK in nucleus taeniae of the amygdala, pTH in ventromedial hypothalamus, and pCREB in mesencephalic central gray, robust nucleus of the arcopallium, and caudomedial nidopallium. However, several effects were critically dependent upon season. E2 decreased pERK in caudomedial nidopallium in the breeding season only and decreased pCREB in the medial preoptic nucleus in the nonbreeding season only. Remarkably, E2 decreased pERK in Hp in the breeding season but increased pERK in Hp in the nonbreeding season. Together, these data demonstrate that E2 has rapid effects on intracellular signaling in multiple regions of the male brain and also demonstrate that rapid effects of E2 can be profoundly different across the seasons.

Effects of central and systemic administration of leptin on neurotransmitter concentrations in specific areas of the hypothalamus

2006 ◽  
Vol 290 (2) ◽  
pp. R306-R312 ◽  
Author(s):  
Kimberly A. Clark ◽  
Sheba M. J. MohanKumar ◽  
Badrinarayanan S. Kasturi ◽  
P. S. MohanKumar
Keyword(s):  
Intraperitoneal Administration ◽  
Ventromedial Hypothalamus ◽  
Systemic Administration ◽  
Male Rats ◽  
Dependent Manner ◽  
Intracerebroventricular Administration ◽  
Dorsal Nucleus ◽  
Intracerebroventricular Injections ◽  
Dose Dependent ◽  
Pituitary Adrenal Axis

Leptin, a hormone produced by adipocytes, has been shown to affect a number of central functions, such as regulation of the hypothalamo-pituitary-adrenal axis, feeding, and body weight regulation. Because hypothalamic monoamines are intricately involved in the regulation of these functions, we hypothesized that leptin may produce its effects by altering the activity of these neurotransmitters. To test this hypothesis, male rats received peripheral (0, 100, or 500 μg ip), or central (0 or 5 μg icv) injections of leptin. The animals were killed 5 h later, and their brains were removed, frozen, and sectioned. Serum was collected to measure leptin and corticosterone by RIA. The paraventricular nucleus (PVN), arcuate nucleus (AN), ventromedial hypothalamus (VMH), dorsomedial dorsal nucleus (DMD), median eminence (ME), and medial preoptic area (MPA) were obtained using Palkovits' microdissection technique, and monoamine concentrations in these areas were determined using HPLC-EC. Intraperitoneal administration of leptin increased serum leptin concentrations in a dose-dependent manner ( P < 0.05). Both intraperitoneal and intracerebroventricular administration of leptin decreased serum corticosterone significantly ( P < 0.05). Norepinephrine (NE) concentration decreased significantly in the PVN, AN, and VMH after both intraperitoneal and intracerebroventricular administration of leptin ( P < 0.05). NE concentrations decreased significantly in the DMN after intracerebroventricular administration of leptin ( P < 0.05). Leptin treatment (both ip and icv) decreased dopamine concentrations significantly in the PVN. Serotonin (5-HT) concentration decreased significantly in the PVN after both intraperitoneal and intracerebroventricular injections of leptin and decreased in the VMH only with intracerebroventricular treatment of leptin. Leptin did not affect any of the monoamines in the ME and MPA. These results indicate that both central and systemic administration of leptin can affect hypothalamic monoamines in a region-specific manner, which, in turn, could mediate many of leptin's central and neuroendocrine effects.

A Determination of Tumor Necrosis Factor Expression in TMJ Inflammation with the Use of Microarray Analysis

2003 ◽  
Vol 82 (10) ◽  
pp. 807-813 ◽  
Author(s):  
R. Spears ◽  
R. Oakes ◽  
C. Moore ◽  
L.L. Bellinger ◽  
B. Hutchins
Keyword(s):  
Microarray Analysis ◽  
Male Rats ◽  
Gene Microarray ◽  
Protein Levels ◽  
Inflammatory Conditions ◽  
Tnf Α ◽  
Gene Microarray Analysis ◽  
Tumor Necrosis Factor Expression ◽  
Inflammatory Changes

Many different factors can lead to inflammatory changes within temporomandibular joint tissues. This investigation examined if the expression of TNF-α and its receptors was altered in TMJ tissues during inflammation. Adult male rats were injected bilaterally with complete Freund’s adjuvant (CFA) into the TMJ or served as uninjected controls and were killed two days after CFA treatment. TMJ tissues were removed, and expression of TNF-α and its receptors was examined via gene microarray analysis, RT-PCR, Western blot, and ELISA. Gene microarray analysis provided evidence for changes in gene expression, notably that TNF-α and TNF-R1, but not TNF-R2, were significantly elevated in CFA-treated TMJ tissues. However, protein levels of TNF-α, TNF-R1, and TNF-R2 were all significantly increased in CFA-treated TMJ tissues. These results indicate that the pro-inflammatory cytokine TNF-α may play a significant role in the onset of inflammatory conditions associated with adjuvant-induced arthritis of the TMJ.

Effects of systemic and local administration of etomidate on adrenocortical steroidogenesis in male rats

1987 ◽  
Vol 114 (3) ◽  
pp. 402-409 ◽  
Author(s):  
H. Jarry ◽  
M. Dietrich ◽  
E. Düker ◽  
W. Wuttke
Keyword(s):  
Inhibitory Effect ◽  
Male Rats ◽  
Local Administration ◽  
Release Rates ◽  
Steroid Synthesis ◽  
Adrenal Steroid ◽  
Freely Moving ◽  
Systemic And Local Administration ◽  
Local Release

Abstract. A method for focal dialysis of the adrenal cortex is introduced allowing determination of adrenal steroid local release rates in conscious, freely moving rats. Etomidate, an anaesthetic drug known to interfere with adrenal steroid synthesis, blocks not only corticosterone but also aldosterone and, to a lesser degree, progesterone release. Intra-adrenal application of the drug via the dialysis system for a defined time resulted in low release rates of corticosterone without inducing sedation of the animals or even anaesthesia. Remaining low steroid concentrations during the next 5 h after cessation of the dialysis with drug-containing medium indicate that the inhibition of steroid synthesis lasted for several hours. It is concluded that the inhibitory effect of etomidate on steroid biosynthesis can be explained on the basis of an interaction of the drug with adrenocortical enzymes without the involvement of hypothalamic or hypophyseal mechanisms.

scholarly journals FEATURES OF ASSESSING THE SEXUAL BEHAVIOR OF MALE RATS IN THE STUDY OF THE EFFECTS OF COMPOUNDS THAT HAVE A STIMULATING EFFECT ON SEXUAL FUNCTION

2020 ◽  
Author(s):  
Svetlana N. Subbotina ◽  
Anastasiya A. Kryazhevskikh ◽  
Aleksey A. Kryazhevskikh ◽  
Mikhail A. Yudin ◽  
Elizaveta I. Eletskaya
Keyword(s):  
Sexual Behavior ◽  
Sexual Function ◽  
Sexual Activity ◽  
Mechanism Of Action ◽  
Experimental Models ◽  
Central Mechanism ◽  
Male Rats ◽  
Test Duration ◽  
Pharmacological Agents

The paper presents a comparative analysis of information content of methods for assessing the copulatory behavior of male rats with the introduction of compounds that have a stimulating effect on the sexual activity of animals. The social significance of the problem of sexual dysfunctions determines the relevance of the development of various experimental models of sexual behavior that allow assessing the effectiveness and safety of new drug. The probability of detecting the activating effect of pharmacological agents on sexual activity directly depends on the correct choice of the experimental model. The drugs of the central mechanism of action galantamine hydrobromide (1mg/kg) and loxidan (1,7mg/kg), were used as pharmacological agents; drugs of peripheral action were yohimbine hydrochloride (2,6mg/kg) and vardenafil hydrochloride (1,7mg/kg). It has been shown that the determination of the stimulating effects of compounds of the central mechanism of action is possible using methods with different testing duration (from 15 to 180min). Thus, the introduction of galantamine enhances the sexual activity of males in terms of the copulation rate, the number of perfect ejaculations and the duration of the post-ejaculatory refractory period, loxidan in terms of the total number of intromissions and relative rest time in tests of limited duration. In the test showing the completed sexual cycle of males, the stimulating effects of galantamine are shown in terms of the number of completed copulatory series and the number of completed ejaculations. To assess the activating effects of compounds of the peripheral mechanism of action, the expediency of using experimental models with a test duration of 30 minutes or more was shown. The most informative test is the test of paired interaction between a male and a female until the male reaches the state of sexual exhaustion. A method with high information content is presented, which provides a high probability of detecting the activating effect of compounds on the sexual function of male rats. Determination of the stimulating effects of compounds of the central mechanism of action is possible using methods with different test duration

Sign in / Sign up

Export Citation Format

Share Document