Video: https://www.youtube.com/watch?v=hTW8CSPVEGc

In this whiteboard episode, we revisit the basal ganglia's intricate circuitry, detailing its five subcortical nuclei—dorsal striatum (caudate/putamen inputs), globus pallidus externa/subthalamic relays, and globus pallidus interna/substantia nigra reticulata outputs—driving the classic direct (facilitatory "go") and indirect (suppressive "no-go") pathways for action selection and inhibition. Excitatory cortical inputs converge on medium spiny neurons, finely tuned by dopamine (D1 excitatory/D2 inhibitory via substantia nigra pars compacta), serotonin, and acetylcholine, to orchestrate habits, motivation, and movement suppression through thalamic modula ...