A spatial and quantitative study of the striatopallidal connection in the monkey

The striatopallidal connection was quantitatively analysed after three-dimensional reconstruction of biocytin-labelled striatal axons. A small striatal region gave rise to one or two elongated bands in each of the pallidal nuclei. Each band consisted of dense axonal plexuses and short axonal arborizations with few branches. Individual axons generally terminated in one band, giving a low density of varicosities on dendrites (10 per 100 microns length). This suggests that the striatopallidal connection can distribute the same striatal information to different remote pallidal regions which can in turn integrate information from different remote striatal regions. Corticostriatal information could thus be preserved or completely transformed according to the size and location of the striatal region activated.