Figure 2.

MORs within the dorsal striatum regulate pair bond formation via inhibition of mating. A, Injections of aCSF or the low dose of CTAP into the dorsal striatum did not inhibit partner preference formation, whereas injections of the high dose of CTAP into this region abolished partner preference. Inset, Site of injection shaded in gray (left) and the binding of MOR within the dorsal striatum (right). B–D, MOR blockade did not affect (B) cage time or (C) total contact time (i.e., time spent in contact with the partner + the stranger) during the partner preference test. However, blockade of MORs with the high dose of CTAP decreased the (D) total number of mating bouts during the cohabitation period (n = 6–10). *p ≤ 0.05.