Motor cortex can directly drive the globus pallidus neurons in a projection neuron type-dependent manner in the rat

• Main Authors: Fuyuki Karube, Susumu Takahashi, Kenta Kobayashi, Fumino Fujiyama
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2019-11-01
• Series: eLife
• Subjects: cerebral cortex; basal ganglia; globus pallidus; subthalamic nucleus; striatum; optogenetics
• Online Access: https://elifesciences.org/articles/49511

The basal ganglia are critical for the control of motor behaviors and for reinforcement learning. Here, we demonstrate in rats that primary and secondary motor areas (M1 and M2) make functional synaptic connections in the globus pallidus (GP), not usually thought of as an input site of the basal ganglia. Morphological observation revealed that the density of axonal boutons from motor cortices in the GP was 47% and 78% of that in the subthalamic nucleus (STN) from M1 and M2, respectively. Cortical excitation of GP neurons was comparable to that of STN neurons in slice preparations. FoxP2-expressing arkypallidal neurons were preferentially innervated by the motor cortex. The connection probability of cortico-pallidal innervation was higher for M2 than M1. These results suggest that cortico-pallidal innervation is an additional excitatory input to the basal ganglia, and that it can affect behaviors via the cortex-basal ganglia-thalamus motor loop.