TY - JOUR
T1 - Crowding stress inhibits serotonin 1A receptor-mediated increases in corticotropin-releasing factor mRNA expression and adrenocorticotropin hormone secretion in the Gulf toadfish
AU - Medeiros, Lea R.
AU - Cartolano, Maria C.
AU - McDonald, M. Danielle
N1 - Funding Information:
Acknowledgments We thank Mr. Ray Hurley and Ms. Debbie Fretz for providing toadfish for the experiments conducted herein, the NSF Grant IOS-0920547 (to M. Danielle McDonald) as well as the Rowlands fellowship and the Knight Fellowship to Lea R. Medeiros.
PY - 2014/2
Y1 - 2014/2
N2 - Stimulation of the serotonin 1A (5-HT1A) receptor subtype by 5-HT has been shown to result in an elevation in plasma corticosteroid levels in both mammals and several species of teleost fish, including the Gulf toadfish (Opsanus beta); however, in the case of teleost fish, it is not clearly known at which level of the hypothalamic-pituitary-interrenal axis the 5-HT1A receptor is stimulated. Additionally, previous investigations have revealed that chronic elevations of plasma cortisol mediate changes in brain 5-HT1A receptor mRNA and protein levels via the glucocorticoid receptor (GR); thus, we hypothesized that the function of centrally activated 5-HT1A receptors is reduced or abolished as a result of chronically elevated plasma cortisol levels and that this response is GR mediated. Our results are the first to demonstrate that intravenous injection of the 5-HT1A receptor agonist, 8-OH-DPAT, stimulates a significant increase in corticotropin-releasing factor (CRF) precursor mRNA expression in the hypothalamic region and the release of adrenocorticotropic hormone (ACTH) from the pituitary of teleost fish compared to saline-injected controls. We also provide evidence that cortisol, acting via GRs, attenuates the 5-HT1A receptor-mediated secretion of both CRF and ACTH.
AB - Stimulation of the serotonin 1A (5-HT1A) receptor subtype by 5-HT has been shown to result in an elevation in plasma corticosteroid levels in both mammals and several species of teleost fish, including the Gulf toadfish (Opsanus beta); however, in the case of teleost fish, it is not clearly known at which level of the hypothalamic-pituitary-interrenal axis the 5-HT1A receptor is stimulated. Additionally, previous investigations have revealed that chronic elevations of plasma cortisol mediate changes in brain 5-HT1A receptor mRNA and protein levels via the glucocorticoid receptor (GR); thus, we hypothesized that the function of centrally activated 5-HT1A receptors is reduced or abolished as a result of chronically elevated plasma cortisol levels and that this response is GR mediated. Our results are the first to demonstrate that intravenous injection of the 5-HT1A receptor agonist, 8-OH-DPAT, stimulates a significant increase in corticotropin-releasing factor (CRF) precursor mRNA expression in the hypothalamic region and the release of adrenocorticotropic hormone (ACTH) from the pituitary of teleost fish compared to saline-injected controls. We also provide evidence that cortisol, acting via GRs, attenuates the 5-HT1A receptor-mediated secretion of both CRF and ACTH.
KW - 8-OH-DPAT
KW - Antalarmin
KW - Hypothalamic-pituitary-interrenal (HPI) axis
KW - RU486
KW - Stress
UR - http://www.scopus.com/inward/record.url?scp=84893522287&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84893522287&partnerID=8YFLogxK
U2 - 10.1007/s00360-013-0793-9
DO - 10.1007/s00360-013-0793-9
M3 - Article
C2 - 24362954
AN - SCOPUS:84893522287
VL - 184
SP - 259
EP - 271
JO - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
JF - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
SN - 0174-1578
IS - 2
ER -