[Abstract Title]. - Society for Neuroscience

Poster
293. Startle and Modulation of Startle
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 293.9/SS37
Topic: F.02.f. Fear and aversive learning and memory
Title: Exercise reduces the anxiogenic effect of intra-bed nucleus of the stria terminalis
injections of mCPP
Authors: *J. H. FOX, S. HAMMACK, W. FALLS;
Dept Psychology, Univ. Vermont, Burlington, VT
Abstract: We have shown that voluntary exercise is associated with reduced anxiety in mice
across several putative models of anxiety. The most widely prescribed pharmacological agents in
the treatment of anxiety disorders are the selective serotonin reuptake inhibitors (SSRIs), which
target brain serotonin (5-HT) systems, and numerous studies have shown that 5-HT
manipulations can alter anxiety-like behaviors. In rats, voluntary exercise has been shown to
increase mRNA for 5-HT1A autoreceptors in the dorsal raphe. Such changes might result in
decreased release of 5-HT in target areas controlling anxiety behaviors. We have shown a
decreased sensitivity to the anxiogenic drug mCPP, a serotonin 2B/C agonist, in mice that had an
opportunity to exercise for 2 weeks. These findings suggest that exercise may help to reduce
anxiety by altering 5-HT systems, perhaps by down regulating post synaptic 5HT 2B/2C
receptors. One area that has been shown to be involved in anxiety-like behaviors is the bed
nucleus of the stria terminalis (BNST). Intra-BNST infusion of mCPP facilitates acoustic startle
indicative of anxiety. Therefore, we assessed whether voluntary exercise would alter the
anxiogenic response to intra-BNST mCPP. Male C57BL/6J mice were given 2 weeks of free
access to either a functioning or non-functioning running wheel in their home cage. Mice were
then given intra-BNST injections of either 1ug/ul of mCPP or vehicle through indwelling
cannula. mCPP facilitated acoustic startle in non-exercising mice. This effect was blunted in
exercising mice suggesting that voluntary exercise alters 5-HT function in the BNST. Studies are
underway to examine the nature of the putative changes in the BNST following exercise.
Disclosures: J.H. Fox , None; S. Hammack, None; W. Falls, None.
Poster
293. Startle and Modulation of Startle
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm