Effect of amphetamine on extracellular acetylcholine and monoamine levels in subterritories of the rat medial prefrontal cortex

The present study sought to investigate the contributions of the dorsal pre limbic/anterior cingulate and ventral prelimbic/infralimbic cortices to the reverse microdialysis of amphetamine (1, 10, 100, 500, and 1000 mu M) on d ialysate acetylcholine, choline, norepinephrine, and serotonin levels. The results demonstrate that basal levels of acetylcholine, choline, and seroto nin were homogeneous within subregions of the medial prefrontal cortex. In contrast, dialysate norepinephrine levels were significantly higher in the anterior cingulate cortex compared with the infralimbic cortex. Reverse mic rodialysis of amphetamine in both subareas of the medial prefrontal cortex produced a dose-dependent increase in norepinephrine and serotonin levels, the magnitude of this effect was similar in both subterritories of the medi al prefrontal cortex. Microinfusion of amphetamine increased dialysate acet ylcholine levels in a dose-dependent manner only in the infralimbic cortex. Finally, amphetamine decreased choline levels in both subregions of the me dial prefrontal cortex. The magnitude of this effect was larger in the ante rior cingulate cortex compared with its infralimbic counterpart. Since depl etions of frontal cortical acetylcholine result in severe cognitive deficit s, the present data raise the possibility that the type of neural integrati ve processes that acetylcholine mediates depends, at least in part, on the subterritories that characterize the medial prefrontal cortex. (C) 2000 Els evier Science B.V. All rights reserved.