Lesions of the medial preoptic area prevent the facilitation of maternal behavior produced by amygdala lesions.
In the present study we tested the hypothesis that the facilitation of maternal behavior produced by amygdala lesions is mediated through the medial preoptic area. Different groups of animals sustained lesions of the corticomedial amygdala (Group AM), the medial preoptic area (Group MPOA), both regions (Group AM-MPOA), the corticomedial amygdala and non MPOA control sites (Group AM-CX), and control sites (Groups LC or SC). Animals were tested for their maternal responses to foster pups presented daily for an 11 day period. It was found that groups sustaining lesions of the amygdala (Group AM and AM-CX) became maternal more rapidly than did Control Groups (LC and SC), Group MPOA, and Group AM-POA. However, animals in Group AM-POA were similar to Groups AM and AM-CX in that they did not avoid pups, whereas groups not sustaining lesions of the amygdala did. These results, taken together, suggest that amygdala-induced facilitation of maternal behavior in the nulliparous females is mediated through the MPOA. They suggest, moreover, the primary effect of removing the amygdala is to reduce avoidance of pups, with only secondary effects on maternal responsiveness.
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D002190:Cannibalism; D005260:Female; D008425:Maternal Behavior; D009425:Nesting Behavior; D009434:Neural Pathways; D011301:Preoptic Area / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains