Evidence that an accumbens to subpallidal GABAergic projection contributes to locomotor activity

Neural projections from nucleus accumbens to subpallidal region, which contains a major GABAergic component, have been demonstrated with anatomical and electrophysiological techniques. The possible contribution of this GABA projection to the initiation of locomotor activity was investigated using neuropharmacological techniques. Injecting picrotoxin, a GABA antagonist, into the ventral globus pallidus increased locomotor activity measured in an open-field test, confirming findings. Locomotor activity was also increased when picrotoxin was injected into the lateral preoptic area, the sublenticular part of the substantia innominata and bed nucleus of the stria terminalis. In another series of experiments locomotor activity initiated by injecting dopamine into the nucleus accumbens was attenuated by pretreating the lateral preoptic area, the substantia innominata and ventral globus pallidus with GABA. These observations provide evidence that GABAergic projections from accumbens to subpallidal region contribute to locomotor activity and raise the possibility that they have a role in exploratory locomotion and in certain goal-directed behaviors.