Amphetamine-induced Fos expression in globus pallidus is altered by frontal cortex injury

Functional recovery from cortical injury may result from subcortical compensatory processes. This study examined basal gangliar expression of the immediate early gene c-fos after unilateral medial agranular cortex (AGm) ablation. In the ipsilateral dorsal globus pallidus of rats demonstrating neglect of contralateral stimuli (sacrificed 5 days postinjury), the numbers of amphetamine-induced Fos-positive nuclei were reduced 37% compared to intact hemisphere values. These reductions were no longer apparent in recovered AGm-ablated rats (sacrificed 21 + days postinjury). These findings mirror in timing and direction the changes in Fos seen in dorsolateral striatum after AGm ablation.