NMDA lesions in the prefrontal cortex delay the onset of maternal, but not infanticidal behavior in pup-naïve adult mice (C57BL/6)

While most pup-naïve adult female mice can display, or be induced (by repeated exposure to pups) to display parental behavior rapidly, adult males are infanticidal or nonparental. The medial prefrontal cortex (mPFC) participates in attentional selection, decision-making, behavioral flexibility, and planning that may be critical in the rapid display of parental or infanticidal behavior. We investigated if NMDA-induced lesions in the mPFC (targeting prelimbic cortex) inhibited maternal or infanticidal behavior in pup-naïve adult female and male mice (C57BL/6), respectively. All Control females displayed full maternal behavior at the first encounter with pups. Lesioned female groups were partially maternal (50%) or nonmaternal (50%). Five repeated exposures of 60-min to pups were needed to induce full maternal behavior in female NMDA-lesioned groups. Control and lesioned males did not show significant differences. Control males displayed nonparental (17%) or infanticidal (83%) behavior, while all lesioned males were infanticidal. There was no difference in general locomotor and exploratory activity (i.e., peripheral crosses, rearings, immobility time) in female or male groups. Nevertheless, females and males of lesioned groups showed a reduction in the number of central crosses and time in the central area of an open field respectively, suggesting an increase in anxiety. Our results show that the mPFC is engaged in the rapid onset of maternal behavior in females, contributing with the motivation and planning of its rapid execution, or reducing the anxiety to the first encounter with pups. In contrast, infanticidal behavior, likely a more impulsive behavior, might require less planning from the mPFC. (PsycInfo Database Record (c) 2021 APA, all rights reserved).