Single pallidal neurons project both to the striatum and thalamus in the rat

Collateral projections of single small pallidal neurons to the striatum and paraventricular nucleus of the thalamus were observed in the rat using a fluorescent retrograde double labeling technique. This population of pallidal cells was almost separate from the more predominant pallidal cell group projecting to the subthalamic nucleus. We propose that the globus pallidus proper might have the same two functionally distinct populations (limbic and motor), that have been well documented in the striatum and entopeduncular nucleus.