Table 1.

Summary of synaptic inputs to areas with known motor directional tuning.

	Directional tuning	Local inhibition	Excitatory external inputs	Inhibitory external inputs
Cerebral cortex	Yes	Yes	Yes (from thalamus and cortex)	No
Motor thalamus	Yes	Yes	Yes (from cortex and deep cerebellar nuclei)	Yes (from globus pallidus)
Globus pallidus	Yes	No	Yes (from subthalamic nucleus and cortex)	Yes (from putamen)
Cerebellar cortex	Yes	Yes	Yes (from mossy and climbing fibers)	No
Deep cerebellar nuclei	Yes	Yes	Yes (from mossy and climbing fibers)	Yes (from cerebellar cortex)