Chronic psychosocial stress enhances vasopressin, but not corticotropin- releasing factor, in the external zone of the median eminence of male rats: relationship to subordinate status

Endocrinology ◽  
1992 ◽  
Vol 131 (2) ◽  
pp. 847-853 ◽  
Author(s):  
D. C. De Goeij
Keyword(s):  
Median Eminence ◽  
Psychosocial Stress ◽  
Corticotropin Releasing Factor ◽  
Male Rats ◽  
External Zone ◽  
Chronic Psychosocial Stress

scholarly journals Chronic Subordinate Colony Housing (CSC) as a Model of Chronic Psychosocial Stress in Male Rats

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e52371 ◽  
Author(s):  
Kewir D. Nyuyki ◽  
Daniela I. Beiderbeck ◽  
Michael Lukas ◽  
Inga D. Neumann ◽  
Stefan O. Reber
Keyword(s):  
Psychosocial Stress ◽  
Male Rats ◽  
Chronic Psychosocial Stress

Effect of dopaminergic and α-adrenergic modulation on corticotropin-releasing factor immunoreactivity in rat hypothalamus

1988 ◽  
Vol 66 (6) ◽  
pp. 754-761 ◽  
Author(s):  
Daniel A. Haas ◽  
Susan R. George
Keyword(s):  
Median Eminence ◽  
Potential Role ◽  
Corticotropin Releasing Factor ◽  
Male Rats ◽  
Dopamine Antagonist ◽  
Adrenergic Modulation ◽  
Selective Depletion ◽  
Dopaminergic Mechanisms ◽  
Monoamine Depletion ◽  
6 Hydroxydopamine

The potential role that dopaminergic mechanisms have in the regulation of corticotropin-releasing factor (CRF) in the hypothalamus was investigated. Adult male rats were administered bromocriptine, a potent dopamine agonist, for periods ranging up to 51 days. Overall, bromocriptine treatment resulted in a significant decline in CRF-like immunoreactivity (CRF-ir). The dopamine antagonist, haloperidol, was administered for similar periods and resulted in no overall significant effect, except for a transient decrease. Treatment with reserpine, known to deplete monoamines including dopamine, induced a significant decrease in CRF-ir 24 h post-treatment. The possibility that the original results were due to α-adrenergic inhibition by bromocriptine and haloperidol was studied next. α1-Stimulation by administration of methoxamine had no significant effect. α2-Stimulation by clonidine significantly reduced hypothalamic CRF-ir. Selective depletion of neurotransmitter from noradrenergic and adrenergic neurons by 6-hydroxydopamine also resulted in a significant reduction of hypothalamic CRF-ir, an effect localized entirely to the median eminence. These results show a reduction in CRF-ir subsequent to either bromocriptine administration, generalized monoamine depletion, α2-stimulation, or selective noradrenaline–adrenaline depletion. No direct dopaminergic effects could be confirmed. These data are consistent with a constant, near-maximal α1-adrenergic effect maintaining hypothalamic CRF concentrations, presumably by inhibition of CRF release from the median eminence.

scholarly journals Tanycyte Pyroglutamyl Peptidase II Contributes to Regulation of the Hypothalamic-Pituitary-Thyroid Axis through Glial-Axonal Associations in the Median Eminence

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2283-2291 ◽  
Author(s):  
Edith Sánchez ◽  
Miguel Angel Vargas ◽  
Praful S. Singru ◽  
Isel Pascual ◽  
Fidelia Romero ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Median Eminence ◽  
Anterior Pituitary ◽  
Cellular Localization ◽  
Third Ventricle ◽  
Male Rats ◽  
Mediobasal Hypothalamus ◽  
External Zone ◽  
The Third ◽  
In Cells

Pyroglutamyl peptidase II (PPII), a highly specific membrane-bound metallopeptidase that inactivates TRH in the extracellular space, is tightly regulated by thyroid hormone in cells of the anterior pituitary. Whether PPII has any role in the region where axons containing hypophysiotropic TRH terminate, the median eminence, is unknown. For this purpose, we analyzed the cellular localization and regulation of PPII mRNA in the mediobasal hypothalamus in adult, male rats. PPII mRNA was localized in cells lining the floor and infralateral walls of the third ventricle and coexpressed with vimentin, establishing these cells as tanycytes. PPII mRNA extended in a linear fashion from the tanycyte cell bodies in the base of the third ventricle to its cytoplasmic and end-feet processes in the external zone of the median eminence in close apposition to pro-TRH-containing axon terminals. Compared with vehicle-treated, euthyroid controls, animals made thyrotoxic by the ip administration of 10 μg l-T4 daily for 1–3 d, showed dramatically increased accumulation of silver grains in the mediobasal hypothalamus and an approximately 80% increase in enzymatic activity. PPII inhibition in mediobasal hypothalamic explants increased TRH secretion, whereas ip injection of a specific PPII inhibitor increased cold stress- and TRH-induced TSH levels in plasma. We propose that an increase in circulating thyroid hormone up-regulates PPII activity in tanycytes and enhances degradation of extracellular TRH in the median eminence through glial-axonal associations, contributing to the feedback regulation of thyroid hormone on anterior pituitary TSH secretion.

Ultrastructural Localization of Acetylcholinesterase in the Arcuate Nucleus and Median Eminence of the Rat

1977 ◽  
Vol 35 ◽  
pp. 440-441
Author(s):  
K.A. Carson ◽  
C.B. Nemeroff ◽  
M.S. Rone ◽  
J.S. Kizer ◽  
J.S. Hanker
Keyword(s):  
Choline Acetyltransferase ◽  
Median Eminence ◽  
Arcuate Nucleus ◽  
Cholinergic Neurons ◽  
Ultrastructural Localization ◽  
Male Rats ◽  
Neonatal Rats ◽  
Good Marker ◽  
Chemical Studies ◽  
High Doses

Biochemical, physiological, pharmacological, and more recently enzyme histo- chemical data have indicated that cholinergic circuits exist in the hypothalamus. Ultrastructural correlates of these pathways such as acetylcholinesterase (AchE) positive neurons in the arcuate nucleus (ARC) and stained terminals in the median eminence (ME) have yet to be described. Initial studies in our laboratories utilizing chemical lesioning and microdissection techniques coupled with microchemical and light microscopic enzyme histo- chemical studies suggested the existence of cholinergic neurons in the ARC which project to the ME (1). Furthermore, in adult male rats with Halasz deafferentations (hypothalamic islands composed primarily of the isolated ARC and the ME) choline acetyltransferase (ChAc) activity, a good marker for cholinergic neurons, was not significantly reduced in the ME and was only somewhat reduced in the ARC (2). Treatment of neonatal rats with high doses of monosodium 1-glutamate (MSG) results in a lesion largely restricted to the neurons of the ARC.

scholarly journals A 16-week aerobic exercise and mindfulness-based intervention on chronic psychosocial stress: a pilot and feasibility study

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Guy A. Prochilo ◽  
Ricardo J.S. Costa ◽  
Craig Hassed ◽  
Richard Chambers ◽  
Pascal Molenberghs
Keyword(s):  
Emotion Regulation ◽  
Exercise Training ◽  
Aerobic Exercise ◽  
Psychosocial Stress ◽  
Retention Rate ◽  
Recruitment Rate ◽  
Trial Registration ◽  
Aerobic Exercise Training ◽  
Definitive Trial ◽  
Chronic Psychosocial Stress

Abstract Objectives Researchers have begun delivering mindfulness and aerobic exercise training concurrently on the premise that a combination intervention will yield salutary outcomes over and above each intervention alone. An estimate of the effect of combination training on chronic psychosocial stress in a nonclinical population has not been established. The objective of this study was to establish protocol feasibility in preparation of a definitive RCT targeting healthy individuals, and to explore the preliminary effect of combination training on reducing chronic psychosocial stress in this population. Methods Twenty-four participants were allocated to a single-arm pre-post study and subjected to 16 weeks of concurrent mindfulness psychoeducation and aerobic exercise training. Feasibility criteria were collected and evaluated. Within-group changes in chronic psychosocial stress, mindfulness, emotion regulation, and cardiorespiratory fitness were also assessed. Primary analyses were based on 17 participants. Results Retention rate, response rate, recruitment rate, and sample size analyses indicate a definitive trial is feasible for detecting most effects with precision. There was also a decline in our primary dependent measure of chronic psychosocial stress (dpretest = −0.56, 95% CI [ −1.14,−0.06]). With regard to secondary measures, there was an increase in the use of cognitive reappraisal, and a reduction in use of maladaptive emotion regulation strategies. We are insufficiently confident to comment on changes in mindfulness and aerobic capacity $\left (\dot {V}O_{2max}\right)$ V ̇ O 2 max . However, there were subgroup improvements in aerobic economy at submaximal exercise intensities. Conclusions We recommend a definitive trial is feasible and should proceed. Trial registration ANZCTR (ID: ACTRN12619001726145). Retrospectively registered December 9, 2019.

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