A reciprocal axonal connection between the subthalamic nucleus and the neostriatum in the cat

Injections of wheatgerm agglutinin conjugated to horseradish peroxidase (WGA-HRP) into several small regions of the head and body of the caudate nucleus and the putamen of the cat result in retrograde cell-labeling of neurons in the ipsilateral subthalamic nucleus. A mediolateral but no rostrocaudal or dorsoventral topography is apparent in the subthalamostriatal projection. Anterograde transport of WGA-HRP and autoradiography after [³H]amino acid injection of the caudate suggest also a reciprocal striatosubthalamic projection.