AXON-SPARING LESIONS OF THE MEDIAL NUCLEUS OF THE AMYGDALA DECREASE AFFILIATIVE BEHAVIORS IN THE PRAIRIE VOLE (MICROTUS-OCHROGASTER) - BEHAVIORAL AND ANATOMICAL SPECIFICITY

The neural basis of affiliative behavior was examined in the prairie v ole, a rodent that exhibits high levels of social contact and paternal behavior. In the first study, the axon-sparing excitotoxin N-methyl-D ,L-aspartic acid (NMA) produced lesions in the basolateral nucleus of the amygdala or the corticomedial amygdala. Males with corticomedial l esions showed significantly less contact with a familiar adult female and a pup when compared with males with lesions of the basolateral nuc leus or controls. This behavioral change was not associated with chang es in exploratory behavior, motor function, performance in an olfactor y task, fearfulness, physical well-being, or body temperature. In a se cond study, NMA lesions restricted to the medial nucleus also decrease d paternal behavior. Neurons in the medial nucleus of the amygdala app ear to be essential for the normal expression of paternal care in this species.