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 Elevated Brain Fatty Acid Amide Hydrolase Induces Depressive-Like Phenotypes in Rodent Models: A Review

2021 ◽  
Vol 22 (3) ◽  
pp. 1047
Author(s):  
Dorsa Rafiei ◽  
Nathan J. Kolla
Keyword(s):  
Depressive Symptoms ◽  
Fatty Acid ◽  
Animal Models ◽  
Fatty Acid Amide Hydrolase ◽  
Acid Amide ◽  
Endocannabinoid System ◽  
Animal Models Of Depression ◽  
Amide Hydrolase ◽  
Fatty Acid Amide

Altered activity of fatty acid amide hydrolase (FAAH), an enzyme of the endocannabinoid system, has been implicated in several neuropsychiatric disorders, including major depressive disorder (MDD). It is speculated that increased brain FAAH expression is correlated with increased depressive symptoms. The aim of this scoping review was to establish the role of FAAH expression in animal models of depression to determine the translational potential of targeting FAAH in clinical studies. A literature search employing multiple databases was performed; all original articles that assessed FAAH expression in animal models of depression were considered. Of the 216 articles that were screened for eligibility, 24 articles met inclusion criteria and were included in this review. Three key findings emerged: (1) FAAH expression is significantly increased in depressive-like phenotypes; (2) genetic knockout or pharmacological inhibition of FAAH effectively reduces depressive-like behavior, with a dose-dependent effect; and (3) differences in FAAH expression in depressive-like phenotypes were largely localized to animal prefrontal cortex, hippocampus and striatum. We conclude, based on the animal literature, that a positive relationship can be established between brain FAAH level and expression of depressive symptoms. In summary, we suggest that FAAH is a tractable target for developing novel pharmacotherapies for MDD.

Preliminary Studies on Bemitradine-Induced Cardiotoxicity in Female Rats

1991 ◽  
Vol 10 (5) ◽  
pp. 511-523 ◽  
Author(s):  
S. Levin ◽  
D. Semler ◽  
S. Gad ◽  
E. Burton ◽  
G. Walsh ◽  
...  
Keyword(s):  
Potential Role ◽  
The Other ◽  
Female Rats ◽  
Separate Experiment ◽  
Direct Effects ◽  
Primary Metabolite ◽  
T Wave ◽  
Mixed Function Oxidases ◽  
Circulating Levels

The mechanism of bemitradine (SC-33643) cardiotoxicity in female rats was investigated in the set of preliminary experiments reported here. Specifically, the involvement of bemitradine metabolites and the potential role of adrenal epinephrine release were examined. Desethylbemi-tradine (the primary metabolite of bemitradine) was shown to be cardiotoxic at oral dosages greater than 300 mg/kg for 7 days. In a separate experiment, a major metabolite (bemitradine glycol) unique to the rat was not cardiotoxic at dosages up to 600 mg/kg for 7 days. Treatment of rats with SKF 525-A enhanced the lethality and the cardiotoxicity of bemitradine. In contrast, prior treatments of rats with phenobarbital resulted in decreased cardiotoxicity of both bemitradine and desethylbemitradine (a bemitradine metabolite presumably further metabolized by the microsomal mixed function oxidases). In other independent experiments, bemitradine-induced cardiotoxicity was shown to be accompanied by adrenal damage and decreases in adrenal epinephrine. Propranolol (a β-antagonist) treatment protected rats against cardiotoxicity. Bemitradine also had a direct effect on the heart, as evidenced in an experiment in which bemitradine caused dose-related increases in the T-wave of the rat ECG complex. These data suggest that (1) both bemitradine and desethylbemitradine may be responsible for the cardiotoxicity, and the other downstream metabolites are not and (2) cardiotoxicity may be due to the combination of direct effects of bemitradine on the rat heart and the bemitradine-mediated release of adrenal epinephrine (a known cardiotoxin at high circulating levels).

scholarly journals Influence of sex, estrous cycle, and estrogen on intracranial dural mast cells

Cephalalgia ◽  
2012 ◽  
Vol 32 (12) ◽  
pp. 924-931 ◽  
Author(s):  
Tanner Boes ◽  
Dan Levy
Keyword(s):  
Mast Cells ◽  
Estrous Cycle ◽  
Potential Role ◽  
Ovarian Hormones ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Migraine Headaches ◽  
Male And Female Rats ◽  
Quantitative Analyses

Background: The frequency of migraine headaches is higher in women than in men and in susceptible women attacks are related to changes in ovarian hormone levels. Intracranial mast cells (MCs) are likely to have a role in migraine headache genesis, and changes in the dural MC population might influence headache susceptibility. The present study thus tested the hypothesis that sex and ovarian hormones influence the density and phenotypic makeup of dural MCs. Methods: Histochemistry combined with quantitative analyses was used to investigate sex differences, estrous cycle and ovarian hormones on dural MC density, phenotype and degranulation level in male and female rats. Results: Our data show that in female rats, dural MC density fluctuates during the estrous cycle and is overall higher than in males. In ovariectomized rats, estradiol, but not progesterone, promoted an increase in dural MC density. This effect was abolished by a splenectomy, suggesting estrogen-related recruitment of MCs from the spleen. Finally, our data suggest that the phenotypic make up of dural MCs, which represents the level of cellular maturity, is also governed by changes in estrogen levels. Conclusions: Given the potential role of dural MCs in triggering headache, our data suggest that estrogen-related modulation of dural MC density and phenotypic makeup could have a role in mediating the higher frequency and severity of headaches such as migraine, in women.

Preclinical evidence for the role of serotonin receptor-subtypes in depression

1992 ◽  
Vol 4 (2) ◽  
pp. 40-45
Author(s):  
B. Olivier ◽  
J. Schipper ◽  
J.A.M. van der Heyden ◽  
A. van Hest ◽  
J. Mos ◽  
...  
Keyword(s):  
Animal Models ◽  
Clinical Research ◽  
Serotonin Receptor ◽  
Antidepressant Effect ◽  
Receptor Subtypes ◽  
Research Support ◽  
Receptor Agonists ◽  
Animal Models Of Depression ◽  
Literature Evidence

SummarySerotonin (5-HT) plays an important role in depression and specific 5-HT reuptake blockers appear to be clinically important antidepressants. It is unclear however, which serotonergic mechanism is involved in the antidepressant effect, certainly when regarding the existence of at least seven 5-HT receptor subtypes. By testing different 5-HT ligands in two animal models of depression (forced swimming and DRL72-S test) and comparison with data from literature, evidence is provided for potential antidepressant qualities of 5-HT1A receptor-agonists and 5-HT1C receptor-antagonists. Compounds binding to 5-HT1B, 5-HT2 and 5-HT3 receptors do not have an antidepressant profile. Results of clinical research support the predicted antidepressive effects of 5-HT1A receptor-agonists.

scholarly journals Essential Role of Ovarian Hormones in Susceptibility to the Consequences of Witnessing Social Defeat in Female Rats

2018 ◽  
Vol 84 (5) ◽  
pp. 372-382 ◽  
Author(s):  
Julie E. Finnell ◽  
Brandon L. Muniz ◽  
Akhila R. Padi ◽  
Calliandra M. Lombard ◽  
Casey M. Moffitt ◽  
...  
Keyword(s):  
Essential Role ◽  
Social Defeat ◽  
Ovarian Hormones ◽  
Female Rats

250. Anergia and Effort-Related Aspects of Motivational Dysfunction in Animal Models of Depressive Symptoms: The Role of Mesolimbic Dopamine and Related Circuitry

2018 ◽  
Vol 83 (9) ◽  
pp. S101
Author(s):  
John Salamone ◽  
Merce Correa ◽  
Samantha Yohn ◽  
Renee Rotolo ◽  
Jen-Hau Yang ◽  
...  
Keyword(s):  
Depressive Symptoms ◽  
Animal Models ◽  
Mesolimbic Dopamine

scholarly journals Affective flexibility without perceptual awareness

2018 ◽  
Author(s):  
Philipp Homan ◽  
H. Lee Lau ◽  
Ifat Levy ◽  
Candace M. Raio ◽  
Dominik R. Bach ◽  
...  
Keyword(s):  
Electric Shock ◽  
Physiological Responses ◽  
Visual Stimuli ◽  
Neural Mechanisms ◽  
The Other ◽  
Perceptual Awareness ◽  
Changing Environment ◽  
Complex Process ◽  
Initial Learning

AbstractIn an ever-changing environment, survival depends on learning which stimuli represent threat, and also on updating such associations when circumstances shift. Humans can acquire physiological responses to threat-associated stimuli even when they are unaware of them, but the role of awareness in updating threat contingencies remains unknown. This complex process – generating novel responses while simultaneously suppressing learned ones – relies on distinct neural mechanisms from initial learning, and has only been shown with awareness. Can it occur unconsciously? Here we show that it can. Participants underwent classical threat conditioning to visual stimuli that were suppressed from their awareness. One of two images was paired with an electric shock; halfway through the experiment, contingencies were reversed and the shock was paired with the other image. We found that physiological responses reflected changes in stimulus-threat pairings independently of stimulus awareness, demonstrating the sophistication of unconscious affective flexibility.

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