Central vasopressin V1a receptor activation is independently necessary for both partner preference formation and expression in socially monogamous male prairie voles

Abstract

The neuropeptide arginine vasopressin (AVP) modulates a variety of species-specific social behaviors. In socially monogamous male prairie voles, AVP acts centrally via vasopressin V1a receptor (V1aR) to facilitate mating induced partner preferences. The display of a partner preference requires at least 2 temporally distinct processes: social bond formation as well as its recall, or expression. Studies to date have not determined in which of these processes V1aR acts to promote partner preferences. Here, male prairie voles were administered intracerebroventricularly a V1aR antagonist (AVPA) at different time points to investigate the role of V1aR in social bond formation and expression. Animals receiving AVPA prior to cohabitation with mating or immediately prior to partner preference testing failed to display a partner preference, while animals receiving AVPA immediately after cohabitation with mating and control animals receiving vehicle at all 3 time points displayed partner preferences. These results suggest that V1aR signaling is necessary for both the formation and expression of partner preferences and that these processes are dissociable.

Figure 1

AVPA administration blocks partner preference formation and expression. A) Experimental timecourse for AVPA administration. All males were cannulated and received three injections, one prior to mating, one after mating, and one prior to partner preference testing. Controls received three vehicle injections while all other subjects received one injection of AVPA and two vehicle injections. B) Graph shows time spent huddling with partner (dark bars) or stranger (open bars) for each treatment group. Subjects that received AVPA prior to cohabitation/mating or prior to testing failed to show a partner preference (p > 0.5) while the control groups, including post-mating injection of AVPA, did show a preference (p < 0.01). C) There were no group differences in the number of mating bouts during the first four hours of cohabitation (p > 0.4). D) There were also no group differences in the number of tunnel crossings during the partner preference test, a measure of locomotion (p > 0.4). Values represent mean + SEM; * indicates p < 0.01.