Home-OrientingBehavior in Rat Pups: The Effect of 2 and 3 Generations of Rehabilitation Following Intergenerational Malnutrition zyx JANINA R. GALLER CHERYL SEELIG zy Department of Child Psychiatry Boston University Medical Center Boston, Massachusetts and Department of Nutrition and Food Science Massachusetts Inst it ute of Technology ambridge, Massachusetts In an earlier study in this laboratory, we examined home-orienting ability in rats with histories zy of intergenerational malnutrition that were rehabilitated postnatally with an adequate protein diet (Galler, 1979). Despite increased size and activity, I st-generation rehabilitated pups showed no improvement in homing ability when compared to malnourished pups. In the current study, offspring of rats with intergen- erational malnutrition were rehabilitated for 2 additional generations and tested for homing ability from postnatal Day 4 through Day zyxwvuts 12. The pups rehabilitated for 2 and 3 generations did not perform as wellas control pups, even though growth and activity returned to normal levels. Furthermore, the rehabilitated pups failed to demonstrate any preference for the nest on all days of testing; in contrast, control pups favored the nest quadrant by Day 8 of life. No significant improvement was evident onany measure from the 2nd to the 3rd generation of rehabilitation. Home-orienting ability, namely, the ability of young animals to locate the nest when displaced from it, is a sensitive indicator of postnatal development which has been applied to kittens (Rosenblatt, Turkewitz, zyxw & Schneirla, 1969) and rat pups (Turkewitz, 1966). In addition, this ability has adaptive significance in that the failure to return may result in decreased feeding time and stimulation. Reprint requests should be sent to Janina R. Galler, M.D., Solomon Carter Fuller Mental Health Center, 85 E. Newton Street, Suite 806, Boston, Massachusetts 02118, U.S.A. Received for publication 31 October 1979 Revised for publication 7 October 1980 zyxwvutsr Developmental Psychobiology, 14(6):541-548 (1981) 0 1981 by John Wiley & Sons, Inc. CCC 001 2-1 630/ 81 / 0060541-08$01 .OO