The basal ganglia function to coordinate motor planning through distinct direct and indirect pathways that modulate cortical output via reciprocal inhibitory-excitatory loops involving striatum, globus pallidus internus/externus, subthalamic nucleus, substantia nigra pars reticulata, and thalamus. The theoretical framework relies on the dual neurotransmitter rule where glutamate signals are excitatory while GABAergic neurons are inhibitory, creating complex disinhibition mechanisms; specifically, the direct pathway reduces inhibition of the motor cortex to initiate movement, whereas the indirect pathway enhances inhibition of the motor cortex to terminate movement by activating the subthalamic nucleus.
The basal ganglia function to coordinate motor planning through distinct direct and indirect pathways that modulate cortical output via reciprocal inhibitory-excitatory loops involving striatum, glob…