Cerebellar cortical interneurons

The cerebellar cortex has three kinds of GABAergic inhibitory interneuron. Stellate cells and basket cells in the molecular layer receive input from parallel fibers and send axons at right angles to them to synapse with distal or proximal dendrites, correspondingly, of neighboring Purkinje cells. Activation of a mossy fiber excites a cluster of granule cells and therefore stimulates linear arrays of on-beam Purkinje cells through the parallel fibers. Though, the basket and stellate cells restrain surrounding off-beam Purkinje cells. This is a surround antagonism method which produces spatial focusing of cerebellar cortex output. It is akin to the lateral inhibition view in sensory systems.

Golgi cells acquire input from parallel fibers and synapse with granule cells to generate feed-back inhibition. In this manner the Golgi cell brings about temporal focusing therefore the net consequence of mossy fiber input is short firing of Purkinje cells.In conclusion, the inhibitory interneurons constrain Purkinje cell output both in time and space.