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.