Exposure of a 'witness rat' to one treated with beta-carboline FG 7142 does not increase dopamine turnover in the medial prefrontal cortex of the 'witness rat'

A method for selectively activating the dopaminergic field of the prefronta l cortex would be highly useful for studies of mesocortical dopamine system s. When a rat ('witness' rat) is exposed to a rat that is undergoing footsh ock, prefrontocortical dopamine metabolism is selectively increased in the witness rat. Since the anxiogenic beta -carboline FG 7142 mimics many of th e effects of footshock, we hypothesized that exposure of a witness-rat to a rat treated with FG 7142 would also increase dopamine metabolism in the pr efrontal cortex. We found that while as expected, FG 7142 itself increased prefrontal cortex dopamine metabolism, there was no significant change in d opamine metabolism in the witness rat. Thus exposure to a rat treated with FG 7142 does not selectively activate the mesocortical dopamine system. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.