CREB phosphorylation and c-Fos expression in the hippocampus of rats during acquisition and recall of a socially transmitted food preference

In the present study, phosphorylation of cAMP-response element binding protein (pCREB) and expression of c-Fos were measured in the dorsal and ventral hippocampus, as well as in a control region, the retrosplenial cortex, of rats following acquisition and recall of a socially transmitted food preference (STFP). Behavioral analyses revealed that STFP-trained rats showed a stronger preference for the demonstrated food than did rats in social-control or odor-control conditions. Rats in a social + odor control condition displayed an intermediate preference that was not significantly different from either STFP-trained rats or the social- or odor-controls. Immunocytochemical analyses revealed increased pCREB-immunoreactivity (ir) in the ventral hippocampus of STFP-trained rats in comparisons with rats in all three control conditions and increased pCREB-ir in the dorsal hippocampus in comparisons with the social- and odor-control conditions. In contrast, c-Fos-ir was greater in the dorsal hippocampus of STEP-trained rats in comparisons with all three control conditions and greater in the ventral hippocampus than rats in the social- and odor-control conditions. Comparisons of pCREB-ir and c-Fos-ir were made also between STFP-trained rats and social-controls following either acquisition or a 48-h recall test. c-Fos-ir was greater in STFP-trained rats after both acquisition and recall, whereas pCREB was greater after recall only. There were no differences in either c-Fos-ir or pCREB-ir in comparisons between trained and control rats in the retrosplenial cortex. The current results indicate that the activity of transcription factors in the hippocampus is related to both acquisition and retention of a socially transmitted food preference. (c) 2004 Wiley-Liss, Inc.