Golgi neurons

Abstract

The Golgi cell is an essential cellular component of the cerebellar cortex and the only source of inhibition to the billions of granule cells forming the cortical input layer. While considered as a single neuronal class, separate from Lugaro cells, Golgi cells form a highly heterogeneous population, both morphologically and immunohistochemically. Golgi cells are interconnected by electrical synapses and connected to other cortical cell types by chemical synapses, forming feedforward and feedback inhibitory loops onto granule cells. Golgi cells are thus ideally placed to control the gain and temporal pattern of granule cell discharge in response to afferent mossy fiber activity. In vivo Golgi cells fire irregularly and respond to peripheral stimuli with brief burst responses or prolonged pauses. In the behaving animal, the firing rate of Golgi cells is modulated and forms sensory-motor receptive fields. Furthermore, Golgi cell activity is coordinated with local field potential oscillations in the beta range both locally and along the parallel fiber beams. Detailed computer models have been generated and predict complex oscillatory behaviors of the granule cell layer network at various frequencies. The impact of these oscillations on the encoding capacity of the granular layer is still debated, and further recordings are needed to understand how Golgi cells affect granule cell spike timing.