LATERAL HABENULA NEURONS ARE NECESSARY FOR THE HORMONAL ONSET OF MATERNAL-BEHAVIOR AND FOR THE DISPLAY OF POSTPARTUM ESTRUS IN NATURALLY PARTURIENT FEMALE RATS

In 16-day pregnant, hysterectomized-ovariectomized and estradiol benzo ate-treated rats, cytotoxic lesions of the lateral habenula (Lhb) prod uced severe deficits in maternal behavior (K. P. Corodimas, J. S. Rose nblatt, M. E. Canfield, & J. I. Morrell, 1993). To determine if defici ts could be found in parturient rats, females were bilaterally injecte d with kainic acid (KB) to produce cytotoxic lesions of the Lhb. Contr ols either received bilateral KA-induced lesions to the hippocampus or were unoperated. All females maintained their pregnancies, underwent parturition, and were tested for maternal behavior (pup retrieval, nur sing, and nestbuilding), general activity, and oromotor carrying. Fema les with lesions of the Lhb had severe disruptions of all components o f maternal behavior and postpartum estrus. These results extend previo us findings that the Lhb is involved in the hormonal onset of maternal behavior and also demonstrate that the Lhb supports the display of po stpartum estrus.