Distribution of the Basal Ganglia and Cerebellar Projections to the Rodent Motor Thalamus

Abstract

Although the rodent cerebellothalamic distribution has been extensively studiedl^1,2,6, the detailed relationship to the basal ganglia thalamic distribution is yet to be determined. In a preliminary report using a double anterograde labeling strategy, Deniau and others5 reported partially segregated and partially overlapping projections from the basal ganglia output nuclei and the cerebellum to the thalamus in the rat. The idea that the rodent motor thalamus largely receives non-overlapping basal ganglia and cerebellar input is partially based on the fmding that the primary nigrothalamic target is the ventromedial nucleus (VM) while the cerebellothalamic afferents project to the ventral anterior lateral nucleus (VAL). Our recent demonstration of robust nigrothalamic projections to VAL in the rat¹⁸ raised the possibility of overlapping basal ganglia and cerebellar afferents in the rat VAL and prompted us to re-investigate the question of segregated basal ganglia and cerebellar afferents to the rodent thalamus.