scholarly journals Co-Expression of c-Fos with Oestradiol Receptor α or Somatostatin in the Arcuate Nucleus, Ventromedial Nucleus and Medial Preoptic Area in the Follicular Phase of Intact Ewes: Alteration after Insulin-Induced Hypoglycaemia

2014 ◽  
Vol 50 (1) ◽  
pp. 68-75 ◽  
Author(s):  
C Fergani ◽  
JE Routly ◽  
DN Jones ◽  
LC Pickavance ◽  
RF Smith ◽  
...  
Keyword(s):  
Arcuate Nucleus ◽  
Preoptic Area ◽  
Medial Preoptic Area ◽  
Follicular Phase ◽  
Ventromedial Nucleus

Effects of ovariectomy on inputs from the medial preoptic area to the ventromedial nucleus of the hypothalamus of young adult rats

2020 ◽  
Author(s):  
Laís da Silva Pereira ◽  
Denise Ribeiro Gobbo ◽  
Jozélia Gomes Pacheco Ferreira ◽  
José de Anchieta de Castro e Horta‐Junior ◽  
Susana Isabel Sá ◽  
...  
Keyword(s):  
Young Adult ◽  
Preoptic Area ◽  
Medial Preoptic Area ◽  
Ventromedial Nucleus ◽  
Adult Rats

A high level of male sexual activity is necessary for the activation of the medial preoptic area and the arcuate nucleus during the ‘male effect’ in anestrous goats

2016 ◽  
Vol 165 ◽  
pp. 173-178 ◽  
Author(s):  
Marie Bedos ◽  
Wendy Portillo ◽  
Jean-Philippe Dubois ◽  
Gerardo Duarte ◽  
José A. Flores ◽  
...  
Keyword(s):  
Sexual Activity ◽  
Arcuate Nucleus ◽  
Preoptic Area ◽  
Medial Preoptic Area ◽  
Male Effect ◽  
High Level

scholarly journals A conceptual model of the influence of stress on female reproduction

Reproduction ◽  
2003 ◽  
pp. 151-163 ◽  
Author(s):  
H Dobson ◽  
S Ghuman ◽  
S Prabhakar ◽  
R Smith
Keyword(s):  
Neuropeptide Y ◽  
Brain Stem ◽  
Paraventricular Nucleus ◽  
Arcuate Nucleus ◽  
Preoptic Area ◽  
Pulse Frequency ◽  
Medial Preoptic Area ◽  
Aminobenzoic Acid ◽  
Female Reproduction ◽  
Cell Recruitment

Intriguingly, similar neurotransmitters and nuclei within the hypothalamus control stress and reproduction. GnRH neurone recruitment and activity is regulated by a balance between stimulation, suppression and permissiveness controlled by noradrenaline, neuropeptide Y and serotonin from the brain stem, impact from glutamate in the medial preoptic area and neuropeptide Y in the arcuate nucleus, in opposition to the restraining influences of gamma-aminobenzoic acid within the medial preoptic area and opioids from the arcuate nucleus. Stress also activates neuropeptide Y perikarya in the arcuate nucleus and brain stem noradrenaline neurones. The latter project either indirectly, via the medial preoptic area, or directly to the paraventricular nucleus to release corticotrophin releasing hormone (CRH) and arginine vasopressin (AVP). Within the medial preoptic area, GnRH neurones synapse with CRH and AVP axons. Stimulation of CRH neurones in the paraventricular nucleus also activates gamma-aminobenzoic acid and opioid neurones in the medial preoptic area and reduces GnRH cell recruitment, thereby decreasing GnRH pulse frequency. Oestradiol enhances stress-induced noradrenaline suppression of LH pulse frequency but when applied in the paraventricular nucleus or brain stem, and not in the medial preoptic area or arcuate nucleus. The importance of CRH and AVP in the medial preoptic area needs confirming in a species other than the rat, which uses adrenal activation to time the onset of the GnRH surge. Another stress-activated pathway involves the amygdala and bed of the nucleus stria terminalis, which contain CRH neurones and accumulate gamma-aminobenzoic acid during stress.

Patterns of preoptic–hypothalamic neuronal activation and LH secretion in female sheep following the introduction and withdrawal of novel males

2019 ◽  
Vol 31 (11) ◽  
pp. 1674
Author(s):  
Penny A. R. Hawken ◽  
Jeremy T. Smith ◽  
Trina Jorre de St Jorre ◽  
Tammi Esmaili ◽  
Christopher J. Scott ◽  
...  
Keyword(s):  
Neural Activity ◽  
Arcuate Nucleus ◽  
Preoptic Area ◽  
Ventromedial Nucleus ◽  
Neural Activation ◽  
Lamina Terminalis ◽  
Neuronal Activation ◽  
Neuroendocrine Response ◽  
Lh Secretion ◽  
Female Sheep

The neuroendocrine response of female sheep to a novel male involves neural activation in the hypothalamus. However, if males are removed, the gonadotrophic signal declines, so the neural activity is likely to change. We examined Fos-immunoreactive (IR) cells in hypothalamic tissues from seasonally anovulatory female sheep exposed to males for 2 or 6h, or for 2h followed by 4h isolation from males. Control females were killed in the absence of male exposure. Male introduction increased LH secretion in all females; male removal was associated with a reduction only in mean and basal LH concentrations. Females exposed to males for 2h had more Fos-IR cells in the arcuate nucleus (ARC), ventromedial nucleus of the hypothalamus (VMH) and organum vasculosum of the lamina terminalis (OVLT) than control females. Fos-IR cells in the preoptic area (POA) were only greater than in control females after 6h exposure to a male. Removal of males decreased the number of Fos-IR cells in the ARC, VMH and OVLT, but not in the POA. Thus, hypothalamic neural activation and LH secretion in female sheep are stimulated by males and decline after male removal. However, activation in the POA persists after removal and may explain the incomplete decline in the LH response.

Sign in / Sign up

Export Citation Format

Share Document