Silencing and stimulating the medial amygdala impairs ejaculation but not sexual incentive motivation in male rats.

Autor: Huijgens PT; Department of Psychology, UiT the Arctic University of Norway, Tromsø, Norway., Heijkoop R; Department of Psychology, UiT the Arctic University of Norway, Tromsø, Norway., Snoeren EMS; Department of Psychology, UiT the Arctic University of Norway, Tromsø, Norway. Electronic address: eelke.snoeren@uit.no.
Jazyk: angličtina
Zdroj: Behavioural brain research [Behav Brain Res] 2021 May 07; Vol. 405, pp. 113206. Date of Electronic Publication: 2021 Feb 24.
DOI: 10.1016/j.bbr.2021.113206
Abstrakt: The medial amygdala (MeA) is a sexually dimorphic brain region that integrates sensory information and hormonal signaling, and is involved in the regulation of social behaviors. Lesion studies have shown a role for the MeA in copulation, most prominently in the promotion of ejaculation. The role of the MeA in sexual motivation, but also in temporal patterning of copulation, has not been extensively studied in rats. Here, we investigated the effect of chemogenetic inhibition and stimulation of the MeA on sexual incentive motivation and copulation in sexually experienced male rats. AAV5-CaMKIIa viral vectors coding for Gi, Gq, or no DREADDs (sham) were bilaterally infused into the MeA. Rats were assessed in the sexual incentive motivation test and copulation test upon systemic clozapine N-oxide (CNO) or vehicle administration. We report that MeA stimulation and inhibition did not affect sexual incentive motivation. Moreover, both stimulation and inhibition of the MeA decreased the number of ejaculations in a 30 min copulation test and increased ejaculation latency and the number of mounts and intromissions preceding ejaculation, while leaving the temporal pattern of copulation intact. These results indicate that the MeA may be involved in the processing of sensory feedback required to reach ejaculation threshold. The convergence of the behavioral effects of stimulating as well as inhibiting the MeA may reflect opposing behavioral control of specific neuronal populations within the MeA.
(Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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