Projections of the anterior coronal gyrus to the subthalamic nucleus in the cat: a combined retrograde and anterograde WGA-HRP study.

In order to re-examine the corticosubthalamic projections in the cat, WGA-HRP was injected into the subthalamic nucleus (STN). Following WGA-HRP injections into the lateral STN, a small number of retrogradely labeled neurons were found in the anterior coronal gyrus (ACG) as well as the anterior sigmoid gyrus. To confirm the projection of the ACG to the lateral STN, which had not been reported previously, WGA-HRP was injected into the ACG. Anterogradely labeled fiber terminals were found in the dorsolateral part of the STN. These results indicate that the ACG influences the STN activity through its direct projections.