DeZeeuwCI+2-2021

Notes about [DeZeeuwCI+2-2021] 1.

1

Chris I. De Zeeuw, Stephen G. Lisberger, and Jennifer L. Raymond. Diversity and dynamism in the cerebellum. Nature Neuroscience, 24(2):160–167, February 2021. URL: http://www.nature.com/articles/s41593-020-00754-9, doi:10.1038/s41593-020-00754-9, Notes: DeZeeuwCI+2-2021.html (this file).

This paper describes some recently discovered connections and changes to the cortical circuit. Specifically:

The discovery of several new connections (Fig. 1, red) highlights a previously unappreciated level of recurrence in the cerebellar circuit. Mutual inhibition of like cell types is common: Purkinje cells inhibit other Purkinje cells 2, molecular layer interneurons inhibit other molecular layer interneurons in a way that is spatially highly structured 3, 4, and Golgi cells inhibit other Golgi cells 5. At the same time, previously hypothesized connections between molecular layer interneurons and Golgi cells have been ruled out 5. There also is electrical coupling among molecular layer interneurons5 and among Golgi cells 6. Circuitry in the granule cell layer has the potential to filter and even reverse the sign of the input from mossy fibers, especially if it incorporates the unipolar brush cells7. In some regions, collaterals from Purkinje cells contact (inhibit) granule cells and create an additional recurrent connection in the input layer 7. Finally, neurons in the cerebellar nuclei provide feedback to the cerebellar cortex, via a mossy fiber-like projection that is subject to plastic changes during learning9,10.

Fig 1. from De Zeeuw CI,et al., 2021.

Figure 1 in De Zeeuw CI (2021) [DeZeeuwCI+2-2021].

x The newly discovered recurrent pathways may endow the cerebellar cortex with an exceptional capacity for dynamic processing and has led to suggestions of several new and previously unappreciated neural computations. Electrical coupling, along with synaptic inputs, could regulate the synchrony of functionally related clusters of interneurons11,12 or could perform local functions for individual neurons, such as linearization of dendritic integration13. The mossy fiber feedback from the cerebellar nucleus could serve to organize the different components of a movement sequence14 or relay a corollary discharge that amplifies learned responses10.

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Laurens Witter, Stephanie Rudolph, R. Todd Pressler, Safiya I. Lahlaf, and Wade G. Regehr. Purkinje Cell Collaterals Enable Output Signals from the Cerebellar Cortex to Feed Back to Purkinje Cells and Interneurons. Neuron, 91(2):312–319, July 2016. URL: https://linkinghub.elsevier.com/retrieve/pii/S0896627316302483, doi:10.1016/j.neuron.2016.05.037, Notes: WitterL+4-2016.html.

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Sarah Rieubland, Arnd Roth, and Michael Häusser. Structured Connectivity in Cerebellar Inhibitory Networks. Neuron, 81(4):913–929, February 2014. URL: https://linkinghub.elsevier.com/retrieve/pii/S0896627313011902, doi:10.1016/j.neuron.2013.12.029, Notes: RieublandS+2-2014.html.

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Charlotte Arlt and Michael Häusser. Microcircuit Rules Governing Impact of Single Interneurons on Purkinje Cell Output In Vivo. Cell Reports, 30(9):3020–3035.e3, March 2020. URL: https://linkinghub.elsevier.com/retrieve/pii/S2211124720301637, doi:10.1016/j.celrep.2020.02.009.

5(1,2)

Court Hull and Wade G. Regehr. Identification of an Inhibitory Circuit that Regulates Cerebellar Golgi Cell Activity. Neuron, 73(1):149–158, January 2012. URL: https://linkinghub.elsevier.com/retrieve/pii/S0896627311009949, doi:10.1016/j.neuron.2011.10.030, Notes: HullC+RegehrWG-2012.html.

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Guillaume P. Dugué, Nicolas Brunel, Vincent Hakim, Eric Schwartz, Mireille Chat, Maxime Lévesque, Richard Courtemanche, Clément Léna, and Stéphane Dieudonné. Electrical Coupling Mediates Tunable Low-Frequency Oscillations and Resonance in the Cerebellar Golgi Cell Network. Neuron, 61(1):126–139, January 2009. URL: https://linkinghub.elsevier.com/retrieve/pii/S0896627308010210, doi:10.1016/j.neuron.2008.11.028.

7

Chong Guo, Laurens Witter, Stephanie Rudolph, Hunter L. Elliott, Katelin A. Ennis, and Wade G. Regehr. Purkinje Cells Directly Inhibit Granule Cells in Specialized Regions of the Cerebellar Cortex. Neuron, 91(6):1330–1341, September 2016. URL: https://linkinghub.elsevier.com/retrieve/pii/S0896627316305037, doi:10.1016/j.neuron.2016.08.011, Notes: GuoC+5-2016.html.