bims-climfi 2022-12-11 papers

Issue of 2022–12–11
two papers selected by
Jun Maruta, Mount Sinai Health System

Elife. 2022 Dec 08. pii: e77603. [Epub ahead of print]11

Feedback inhibition underlies new computational functions of cerebellar interneurons.

Hunter E Halverson, Jinsook Kim, Andrei Khilkevich, Michael D Mauk, George J Augustine.

The function of a feedback inhibitory circuit between cerebellar Purkinje cells and molecular layer interneurons (MLIs) was defined by combining optogenetics, neuronal activity recordings both in cerebellar slices and in vivo, and computational modeling. Purkinje cells inhibit a subset of MLIs in the inner third of the molecular layer. This inhibition is non-reciprocal, short-range (less than 200 mm) and is based on convergence of 1-2 Purkinje cells onto MLIs. During learning-related eyelid movements in vivo, the activity of a subset of MLIs progressively increases as Purkinje cell activity decreases, with Purkinje cells usually leading the MLIs. Computer simulations indicate that these relationships are best explained by the feedback circuit from Purkinje cells to MLIs and that this feedback circuit plays a central role in making cerebellar learning efficient.

Keywords: neuroscience

DOI: https://doi.org/10.7554/eLife.77603

Commun Biol. 2022 Dec 03. 5(1): 1328

Postsynaptic plasticity of Purkinje cells in mice is determined by molecular identity.

Stijn Voerman, Bastiaan H A Urbanus, Martijn Schonewille, Joshua J White, Chris I De Zeeuw.

Cerebellar learning is expressed as upbound or downbound changes in simple spike activity of Purkinje cell subpopulations, but the underlying mechanism remains enigmatic. By visualizing murine Purkinje cells with different molecular identities, we demonstrate that the potential for induction of long-term depression is prominent in downbound and minimal in the upbound subpopulation. These differential propensities depend on the expression profile, but not on the synaptic inputs, of the individual Purkinje cell involved, highlighting the functional relevance of intrinsic properties for memory formation.

DOI: https://doi.org/10.1038/s42003-022-04283-y