Habituation reduces novelty-induced FOS expression in the striatum and cingulate cortex.

Exposure to novel environments is known to induce c-fos expression in the cingulate cortex and dorsomedial striatum. This study examined the effects of 1, 3, and 7 days of exposure to sequential exposure to three novel environments. It was hypothesized that the ability of novel environment shuttling (NES) would induce c-fos expression as indicated by cells displaying FOS-like immunoreactivity (FLI) in the striatum and cingulate cortex which would decrease with repeated exposure. NES elicited FLI in both the cingulate cortex and striatum when compared to home-cage controls and this effect was attenuated with repeated exposure. Behavioral measures of activity decreased with repeated exposure suggesting that the decrease in FLI may be due to either a reduction in motor activity or increasing familiarity with the environments.