A study of the contribution of hippocampal-accumbens-subpallidal projections to locomotor activity.

Locomotor activity recorded in an automated open-field apparatus was increased substantially by unilateral injections of carbachol, a cholinergic agonist, into the dentate gyrus of the hippocampus. Hyperactivity elicited in this way was reduced significantly when glutamate antagonists were injected into the ipsilateral nucleus accumbens. Injecting gamma-aminobutyric acid into the ipsilateral subpallidal region also reduced the hyperactivity from injections of carbachol into the dentate gyrus. When these compounds were injected into the contralateral accumbens and subpallidal region, respectively, there was little or no reduction in the carbachol-elicited locomotor activity. These observations suggest that neural pathways fom hippocampus to accumbens to subpallidal region may contribute to locomotor activity.