Working PaperArticleVersion 2This version is not peer-reviewed
Increased Excitability of Serotoninergic Neurons and Reduced Concentrations of Circulating Corticosteroids Two Weeks After Chronic Stress in Rats: Mechanisms Involved
Version 1
: Received: 27 February 2021 / Approved: 1 March 2021 / Online: 1 March 2021 (13:46:41 CET)
Version 2
: Received: 14 July 2021 / Approved: 15 July 2021 / Online: 15 July 2021 (10:40:31 CEST)
How to cite:
Dremencov, E.; Grinchii, D.; Buzgoova, K.; Lapshin, M.; Komelkova, M.; Graban, J.; Tseilikman, O.; Tseilikman, V.; Jezova, D. Increased Excitability of Serotoninergic Neurons and Reduced Concentrations of Circulating Corticosteroids Two Weeks After Chronic Stress in Rats: Mechanisms Involved. Preprints2021, 2021030018
Dremencov, E.; Grinchii, D.; Buzgoova, K.; Lapshin, M.; Komelkova, M.; Graban, J.; Tseilikman, O.; Tseilikman, V.; Jezova, D. Increased Excitability of Serotoninergic Neurons and Reduced Concentrations of Circulating Corticosteroids Two Weeks After Chronic Stress in Rats: Mechanisms Involved. Preprints 2021, 2021030018
Dremencov, E.; Grinchii, D.; Buzgoova, K.; Lapshin, M.; Komelkova, M.; Graban, J.; Tseilikman, O.; Tseilikman, V.; Jezova, D. Increased Excitability of Serotoninergic Neurons and Reduced Concentrations of Circulating Corticosteroids Two Weeks After Chronic Stress in Rats: Mechanisms Involved. Preprints2021, 2021030018
APA Style
Dremencov, E., Grinchii, D., Buzgoova, K., Lapshin, M., Komelkova, M., Graban, J., Tseilikman, O., Tseilikman, V., & Jezova, D. (2021). Increased Excitability of Serotoninergic Neurons and Reduced Concentrations of Circulating Corticosteroids Two Weeks After Chronic Stress in Rats: Mechanisms Involved. Preprints. https://doi.org/
Chicago/Turabian Style
Dremencov, E., Vadim Tseilikman and Daniela Jezova. 2021 "Increased Excitability of Serotoninergic Neurons and Reduced Concentrations of Circulating Corticosteroids Two Weeks After Chronic Stress in Rats: Mechanisms Involved" Preprints. https://doi.org/
Abstract
Exposure to predator scent (PS) has been used as a model of stress associated with danger to life and body integrity. We tested the hypothesis that repeated PS exposure alters the excitability of serotonin (5-HT) neurons of the dorsal raphe nucleus. To study the mechanisms involved, we approached serum and adrenal corticosterone and aldosterone concentrations, as well as cortical brain-derived neurotrophic factor (BDNF) expression. Adult male Sprague-Dawley rats were exposed to PS for ten minutes daily for ten consecutive days. Two weeks after the last exposure, electrophysiological and biochemical assessments were performed. Measurements by in vivo electrophysiology showed increased spontaneous firing activity of 5-HT neurons in rats exposed to PS. PS exposure resulted in reduced serum corticosterone and aldosterone concentrations. Concentrations of both corticosteroids in the adrenal glands, as well as the relative weight of the adrenals, were unaffected. The gene expression of hippocampal BDNF of rats exposed to PS remained unaltered. In conclusion, repeated exposure of rats to PS leads to enhanced firing activity of 5-HT neurons accompanied by reduced serum, but not adrenal aldosterone and corticosterone concentrations. Reduced corticosteroid concentrations in the blood appear to be the result of increased metabolism and/or tissue uptake rather than altered steroidogenesis. The decrease in circulating corticosterone in rats experienced repeated PS may represent part of the mechanisms leading to increased excitability of 5-HT neurons. The increase in 5-HT neuronal firing activity might be an important compensatory mechanism designated to diminish the harmful effects of the repeated PS exposure on the brain.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received:
15 July 2021
Commenter:
Eliyahu Dremencov
Commenter's Conflict of Interests:
Author
Comment: It is a revised version of our manuscript "Effect of repeated predator scent exposure on excitability of serotonin neurons and stress markers in rats" which was previously submitted to the IJMS. It is revised in accordance with the recommendations of the editorial board. New molecular studies supporting the working hypothesis were added. The title and the abstract were amended to make them more corresponding to the main message of the study.
Commenter: Eliyahu Dremencov
Commenter's Conflict of Interests: Author