scholarly journals Role of the posterodorsal medial amygdala in predator odour stress‐induced puberty delay in female rats

2019 ◽  
Vol 31 (6) ◽  
pp. e12719
Author(s):  
Xiao Feng Li ◽  
Daniel A. Adekunbi ◽  
Hussah M. Alobaid ◽  
Shengyun Li ◽  
Michel Pilot ◽  
...  
Keyword(s):  
Female Rats ◽  
Medial Amygdala ◽  
Predator Odour

SOME ASPECTS OF THE FUNCTION OF FSH- AND LH-LIKE HORMONES IN NORMAL AND HYPOPHYSECTOMIZED FEMALE RATS, IN CONNECTION WITH RESERPINE ADMINISTRATION

1965 ◽  
Vol 49 (1) ◽  
pp. 28-38
Author(s):  
M. Grönroos ◽  
E. Mäkinen ◽  
K. Lahtinen ◽  
R. Tirri
Keyword(s):  
Mechanism Of Action ◽  
Biological Effect ◽  
Female Rats ◽  
Histological Picture ◽  
Peripheral Effect ◽  
Pituitary Secretion

ABSTRACT The effect of reserpine on the secretion of FSH and LH was studied as well as the role of the peripheral effect of reserpine after hypophysectomy. The results in the unoperated animals suggest that reserpine inhibits the pituitary secretion of both FSH and LH. Both these hormones combined with reserpine had a very different biological effect than was seen without reserpine. HCG (LH-like) and particularly PMS (FSH-like) hormones combined with reserpine caused definite enlargement of the ovaries. In the hypophysectomized groups, the effect of the PMS and HCG hormones administered together with reserpine or without it was the same with regard to the weight of the ovaries, but not with regard to their histological picture. On the basis of these results, reserpine may be said to have a peripheral effect although the nature of its mechanism of action is difficult to state. Reserpine probably affects the ovaries by inhibiting the follicular cycle and, consequently, the formation of new and more mature follicles.

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.

scholarly journals Progesterone after Estradiol Modulates Shuttle-Cage Escape by Facilitating Volition

2015 ◽  
Vol 9s1 ◽  
pp. JEN.S32735
Author(s):  
Darryl J. Mayeaux ◽  
Sarah M. Tandle ◽  
Sean M. Cilano ◽  
Matthew J. Fitzharris
Keyword(s):  
Depressive Symptoms ◽  
Animal Models ◽  
Electric Shock ◽  
Ovarian Hormones ◽  
Learning Task ◽  
The Other ◽  
Female Rats ◽  
Animal Models Of Depression ◽  
Escape Learning

In animal models of depression, depression is defined as performance on a learning task. That task is typically escaping a mild electric shock in a shuttle cage by moving from one side of the cage to the other. Ovarian hormones influence learning in other kinds of tasks, and these hormones are associated with depressive symptoms in humans. The role of these hormones in shuttle-cage escape learning, however, is less clear. This study manipulated estradiol and progesterone in ovariectomized female rats to examine their performance in shuttle-cage escape learning without intentionally inducing a depressive-like state. Progesterone, not estradiol, within four hours of testing affected latencies to escape. The improvement produced by progesterone was in the decision to act, not in the speed of learning or speed of escaping. This parallels depression in humans in that depressed people are slower in volition, in their decisions to take action.

scholarly journals Circulating Secretin Activates Supraoptic Nucleus Oxytocin and Vasopressin Neurons via Noradrenergic Pathways in the Rat

Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2681-2688 ◽  
Author(s):  
Sathya Velmurugan ◽  
Paula J. Brunton ◽  
Gareth Leng ◽  
John A. Russell
Keyword(s):  
Amino Acid ◽  
Firing Rate ◽  
Noradrenaline Release ◽  
Supraoptic Nucleus ◽  
Female Rats ◽  
Adrenoceptor Antagonist ◽  
Intracerebroventricular Infusion ◽  
Neuroendocrine Neurons ◽  
Vasopressin Neurons

Secretin is a 27-amino acid brain-gut peptide from duodenal S-cells. We tested the effects of systemic administration of secretin to simulate its postprandial release on neuroendocrine neurons of the supraoptic nucleus (SON) in urethane-anesthetized female rats. Secretin dose-dependently increased the firing rate of oxytocin neurons, more potently than cholecystokinin, and dose-dependently increased plasma oxytocin concentration. The effect of secretin on SON vasopressin neurons was also predominantly excitatory, in contrast to the inhibitory actions of cholecystokinin. To explore the involvement of noradrenergic inputs in secretin-induced excitation, benoxathian, an α1-adrenoceptor antagonist, was infused intracerebroventricularly. Benoxathian intracerebroventricular infusion blocked the excitation by secretin of both oxytocin and vasopressin neurons. To test the role of local noradrenaline release in the SON, benoxathian was microdialyzed onto the SON. The basal firing rate of oxytocin neurons was slightly reduced and the secretin-induced excitation was attenuated during benoxathian microdialysis. Hence, noradrenergic pathways mediate the excitation by systemic secretin of oxytocin neurons via α1-adrenoceptors in the SON. As both systemic secretin and oxytocin are involved in regulating gastrointestinal functions and natriuresis, systemically released secretin might act partly through oxytocin.

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