Purkinje cells directly inhibit granule cells in specialized regions of the cerebellar cortex

By Chong Guo, L. Witter, Stephanie Rudolph, Hunter L. Elliott, K. Ennis, Wade G. Regehr. 2016

74 citations recorded by the source corpus.

Summary Inhibition of granule cells plays a key role in gating the flow of signals into the cerebellum, and it is thought that Golgi cells are the only interneurons that inhibit granule cells. Here we show that Purkinje cells, the sole output neurons of the cerebellar cortex, also directly inhibit granule cells via their axon collaterals. Anatomical and optogenetic studies indicate that this non-canonical feedback is region specific: it is most prominent in lobules that regulate eye movement and process vestibular information. Collaterals provide fast, slow and tonic inhibition to granule cells, and thus allow Purkinje cells to regulate granule cells excitability on multiple time scales. We propose that this feedback mechanism could regulate excitability of the input layer, contribute to sparse coding and mediate temporal integration.

Subfields: Cellular and Molecular Neuroscience, Neurology, Sensory Systems

Citations in the corpus

• Re-evaluating circuit mechanisms underlying pattern separation (2019, neutral): “While in general cerebellar granule cells only receive inhibition from Golgi cells - with the exception of recently discovered inhibitory feedback (Ankri et al., 2015; Guo et al., 2016) and external broad inhibition (Jaarsma et al.”
• Computational Principles of Supervised Learning in the Cerebellum (2018, unknown): “…until it learns to generate the desired response. tuning is achieved by adjusting connection weights in artificial neural networks (Alpaydin 2014, Hagan et al. 2014, Jenkins et al. 1996) or by adjusting the strength of synapses or other properties of neurons in the brain (i.e., neural…”