Abstract

Effects of FGF-2 on individual differences in anxiety-like behavior

J. Perez; C.A. Turner; S. Clinton; J. Stead; S.J. Watson and H. Akil
Society for Neuroscience annual meeting. 2005.

While FGF2 has been shown to respond to acute stress and corticosterone treatment, (Molteni et al. 2001), its role in emotional reactivity has not yet been described. Recent data from our laboratory shows that high responder (HR) animals, characterized by high locomotor activity and enhanced corticosterone response to a novel environment, show significantly higher basal levels of FGF2 mRNA in the hippocampus than low responder (LR) animals. Since increased activity in a novel environment has been associated with decreased anxiety-like behavior, FGF2 may play a role in emotional reactivity. In the present study, we tested the hypothesis that individual differences in emotional behavior may be regulated by FGF2. Adult male Sprague-Dawley rats selectively bred for HR and LR phenotypic behavior were either administered FGF2 or vehicle. Following this treatment, all animals were returned to normal housing conditions for 8hrs, at which point animals were tested in the elevated plus-maze (EPM) and then sacrificed for in situ hybridization. Animals treated with FGF2 showed significantly higher anxiety-like behavior by spending less time on the open arms of the EPM compared to controls. Interestingly, the anxiogenic response of FGF2 treatment was specific to HR animals, as no change was observed in LR animals. Whether these differences relate to alterations in corticosterone levels, or glucocorticoid receptor expression in the hippocampus remains to be determined. In this study we present some evidence showing that FGF2 may be implicated in modulating individual differences in emotional responses. Supported by; Conte Grant 2 P50 MH60398, NIMH Program Project Grant P01 MH42251, RO1 DA13386, N00014-02-1-0879, and The Pritzker Neuropsychiatric Disorder Research Consortium Fund.