Multiple Output Channels in the Basal Ganglia

TLDR

Basal ganglia–cortex circuits are essential for generating and controlling voluntary movement. The study used retrograde HSV‑1 transport in Cebus monkeys to map connections between the GPi and primary motor, supplementary motor, and ventral premotor cortices. The GPi contains spatially distinct regions that project to primary motor, supplementary motor, and ventral premotor cortices, forming discrete output channels that provide a new anatomical framework for basal ganglia function in skeletomotor control.

Abstract

The neural circuits that link the basal ganglia with the cerebral cortex are critically involved in the generation and control of voluntary movement. Retrograde transneuronal transport of herpes simplex virus type 1 was used to examine the organization of connections in the cebus monkey between an output nucleus of the basal ganglia, the internal segment of the globus pallidus (GPi), and three cortical areas: the primary motor cortex, the supplementary motor area, and the ventral premotor area. Spatially separate regions of the GPi were labeled after virus injections into each cortical area. The GPi projects to multiple cortical motor areas, and this pallidal output is organized into discrete channels. This information provides a new anatomical framework for examining the function of the basal ganglia in skeletomotor control.