Prior stress and vasopressin promote corticotropin-releasing factor inhibition of serotonin release in the central nucleus of the amygdala

Patrick J Ronan; Wayne J Korzan; Philip L Johnson; Christopher A Lowry; Kenneth J Renner; Cliff H Summers

doi:10.3389/fnbeh.2023.1148292

Prior stress and vasopressin promote corticotropin-releasing factor inhibition of serotonin release in the central nucleus of the amygdala

Front Behav Neurosci. 2023 Mar 30:17:1148292. doi: 10.3389/fnbeh.2023.1148292. eCollection 2023.

Authors

Patrick J Ronan^{1

2

3

4}, Wayne J Korzan⁵, Philip L Johnson⁶, Christopher A Lowry⁷, Kenneth J Renner^{4

6}, Cliff H Summers^{1

4

6}

Affiliations

¹ Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, United States.
² Department of Psychiatry, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, United States.
³ Laboratory for Clinical and Translational Research in Psychiatry, Department of Veterans Affairs Medical Center, Denver, CO, United States.
⁴ Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States.
⁵ Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, United States.
⁶ Department of Biology, University of South Dakota, Vermillion, SD, United States.
⁷ Department of Integrative Physiology, University of Colorado, Boulder, Boulder, CO, United States.

Abstract

Corticotropin-releasing factor (CRF) is essential for coordinating endocrine and neural responses to stress, frequently facilitated by vasopressin (AVP). Previous work has linked CRF hypersecretion, binding site changes, and dysfunctional serotonergic transmission with anxiety and affective disorders, including clinical depression. Crucially, CRF can alter serotonergic activity. In the dorsal raphé nucleus and serotonin (5-HT) terminal regions, CRF effects can be stimulatory or inhibitory, depending on the dose, site, and receptor type activated. Prior stress alters CRF neurotransmission and CRF-mediated behaviors. Lateral, medial, and ventral subdivisions of the central nucleus of the amygdala (CeA) produce CRF and coordinate stress responsiveness. The purpose of these experiments was to determine the effect of intracerebroventricular (icv) administration of CRF and AVP on extracellular 5-HT as an index of 5-HT release in the CeA, using in vivo microdialysis in freely moving rats and high performance liquid chromatography (HPLC) analysis. We also examined the effect of prior stress (1 h restraint, 24 h prior) on CRF- and AVP-mediated release of 5-HT within the CeA. Our results show that icv CRF infusion in unstressed animals had no effect on 5-HT release in the CeA. Conversely, in rats with prior stress, CRF caused a profound dose-dependent decrease in 5-HT release within the CeA. This effect was long-lasting (240 min) and was mimicked by CRF plus AVP infusion without stress. Thus, prior stress and AVP functionally alter CRF-mediated neurotransmission and sensitize CRF-induced inhibition of 5-HT release, suggesting that this is a potential mechanism underlying stress-induced affective reactivity in humans.

Keywords: 5-HT; AVP; CRF; CeA; affective disorders; restraint stress.

Grants and funding

PR receives support from the Department of Veterans Affairs (Merit Review Award, I01BX004712), the National Institutes of Health (National Institute of Mental Health, NIMH R01 MH122954 and National Institute of General Medical Sciences, NIGMS U54GM128729), and the Great Plains Veterans Research Foundation. Other support includes the National Institute of Mental Health of the National Institutes of Health grants R15MH125306, R15MH104485 (CS), and NIH P20 RR15567 (PR, KR, and CS).