Sexual dimorphism and the NMDA receptor in alloparental behavior in juvenile prairie voles (Microtus ochrogaster).

The prairie vole (Microtus ochrogaster) exhibits parental behavior in both males and females and extensive alloparenting in juveniles. The authors studied the effects on juvenile alloparenting of antagonists for the PCP, glycine, and glutamate sites on the N-methyl-D-aspartate (NMDA) receptor. In male voles, all 3 drugs had an inverted-U dose-response curve. This change could not be attributed to fear of the pup or a nonspecific impairment of cognition, level of locomotor activity, or motor coordination. The PCP site antagonist had a U-shaped dose-response curve in females, the opposite of that in males, but neither of the other drugs changed female alloparental behavior. Both male and female voles exhibit alloparental behavior, but its neurobiological underpinnings are sexually dimorphic in juveniles.