Meeting Abstract

P2.22  Jan. 5  Sex difference in thermotactile induction of filial huddling preferences in rats, Rattus norvegicus. KOJIMA, S.*; ALBERTS, J. R. ; Indiana University, Bloomington; Indiana University, Bloomington skojima@indiana.edu

By Postnatal Day (PD) 15, rat pups huddle preferentially with a target bearing odors typical of their mother. Normally this developmental preference is for species-typical odors, but it can be altered by: (a.) altering the odor associated with maternal care or (b.) associating via daily pairings of an odor with just the thermotactile component of maternal contact. Recent studies in our laboratory demonstrated that five, daily, 2-hr-long odor exposures with a foster mother induced a new affiliative preference, but only in female pups. Female pups conditioned on PDs 10 -14 preferred to huddle with an object bearing an odor associated with maternal care, whereas male pups did not develop the odor preference. No sex difference was found in pups conditioned on PDs 5-10. The present study was designed to examine whether a sex difference also exists for filial learning derived from the thermotactile component of maternal care. In 2-hr-long conditioning sessions on PDs 10-14, pups were provided a heated furry tube (35.5�C) with which to huddle in a 23�C chamber. This condition simulated a colony condition where a pup has physical contact with dam. On PD 15, pups received a 2-choice olfactory huddling test. Huddling preference for the conditioned odor was found in females, but not in males, suggesting that among the different stimuli provided from dam, thermotactile stimulation may be the key determinant of the sex difference in filial huddling preference in rats.