Purkinje cell outputs selectively inhibit a subset of unipolar brush cells in the input layer of the cerebellar cortex.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34369877.
- Also identified by DOI 10.7554/eLife.68802 and PMC identifier 8352585.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Circuitry of the cerebellar cortex is regionally and functionally specialized. Unipolar brush cells (UBCs), and Purkinje cell (PC) synapses made by axon collaterals in the granular layer, are both enriched in areas that control balance and eye movement. Here, we find a link between these specializations in mice: PCs preferentially inhibit metabotropic glutamate receptor type 1 (mGluR1)-expressing UBCs that respond to mossy fiber (MF) inputs with long lasting increases in firing, but PCs do not inhibit mGluR1-lacking UBCs. PCs inhibit about 29% of mGluR1-expressing UBCs by activating GABA<sub>A</sub> receptors (GABA<sub>A</sub>Rs) and inhibit almost all mGluR1-expressing UBCs by activating GABA<sub>B</sub> receptors (GABA<sub>B</sub>Rs). PC to UBC synapses allow PC output to regulate the input layer of the cerebellar cortex in diverse ways. Based on optogenetic studies and a small number of paired recordings, GABA<sub>A</sub>R-mediated feedback is fast and unreliable. GABA<sub>B</sub>R-mediated inhibition is slower and is sufficiently large to strongly influence the input-output transformations of mGluR1-expressing UBCs.
Medical subject headings
- Axons
- Purkinje Cells
- Synapses