Interaction of the pallidum, pedunculopontine nucleus, zona incerta, and deep mesencephalic nucleus - Structures of the morphofunctional basal ganglia system

摘要

The organization of the projections of substructures of the zona incerta (ZI), pedunculopontine nucleus (PPN), and the deep mesencephalic nucleus (NPM) complex and functionally diverse pallidal structures of the dog brain (n = 20) were studied by a method based on anterograde and posterograde axonal transport of horseradish peroxidase. The globus pallidus and entopeduncular nucleus were found to be connected by reciprocal connections with the dorsal, ventral, and caudal sectors of the ZI and with the NPM, and the lateral segment of the diffuse zone and the compact zone of the PPN. These same pallidal nuclei were connected to the rostral sector of the ZI, the cuneate and subcuneate nuclei of the NPM, the medial segment of the diffuse zone of the PPN via ipsilateral projections. Of all the structures studied, reciprocal connections with the ventral pallidum were seen only with the lateral segment of the diffuse zone and the compact zone of the PPN. The possible pathways for conduction of functionally diverse information and its integration in the projection systems studied here are discussed.