Korbzellen

Korbzellen, or basket cells, are a class of GABAergic inhibitory interneurons in the cerebellar cortex. They disperse inhibitory input onto the bodies and axon initial segments of Purkinje cells, forming pericellular “basket” structures that give the cells their name. This perisomatic arrangement allows fast and potent control of Purkinje cell output.

Anatomy and location: Korbzellen reside primarily in the molecular layer of the cerebellar cortex. Their axons extend toward the Purkinje cell layer and enwrap the somata and initial segments of Purkinje cells, producing pinceau-like endings around the axon initial segment. They are typically fast-spiking and commonly express parvalbumin, a calcium-binding protein associated with high-frequency firing.

Connectivity and signaling: Korbzellen receive excitatory input from granule cell parallel fibers and other excitatory afferents, and they provide inhibitory GABAergic output to Purkinje cells. The resulting perisomatic inhibition shapes the precise timing of Purkinje cell simple and complex spike activity, contributing to the cerebellum’s ability to regulate motor coordination and timing.

Function and role: By constraining Purkinje cell activity, Korbzellen participate in fast, temporally precise regulation of cerebellar output. They are integral to feedforward inhibition in the cerebellar circuit and help refine motor learning, adaptation to movement dynamics, and coordination.

Development and diversity: Korbzellen arise from cerebellar interneuron progenitors during development and mature postnatally. They display variability in morphology and synaptic connectivity, but share the core role of providing perisomatic inhibition to Purkinje cells. They are distinct from stellate cells, which primarily target Purkinje cell dendrites.

See also: Purkinje cells, stellate cells, granule cells, cerebellar cortex.