scholarly journals Purkinje cell outputs selectively inhibit a subset of unipolar brush cells in the input layer of the cerebellar cortex

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Chong Guo ◽  
Stephanie Rudolph ◽  
Morgan E Neuwirth ◽  
Wade G Regehr
Keyword(s):  
Purkinje Cell ◽  
Cerebellar Cortex ◽  
Metabotropic Glutamate Receptor ◽  
Mossy Fiber ◽  
Brush Cells ◽  
Metabotropic Glutamate ◽  
Unipolar Brush Cells ◽  
Input Layer ◽  
Almost All ◽  
Control Balance

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 GABAA receptors (GABAARs) and inhibit almost all mGluR1-expressing UBCs by activating GABAB receptors (GABABRs). 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, GABAAR-mediated feedback is fast and unreliable. GABABR-mediated inhibition is slower and is sufficiently large to strongly influence the input-output transformations of mGluR1-expressing UBCs.

scholarly journals Purkinje cell outputs selectively inhibit a subset of unipolar brush cells in the input layer of the cerebellar cortex

2021 ◽  
Author(s):  
Chong Guo ◽  
Stephanie Rudolph ◽  
Morgan E. Neuwirth ◽  
Wade G. Regehr
Keyword(s):  
Purkinje Cell ◽  
Cerebellar Cortex ◽  
Mossy Fiber ◽  
Input Output ◽  
Brush Cells ◽  
Unipolar Brush Cells ◽  
Input Layer ◽  
Inhibitory Feedback ◽  
Almost All ◽  
Control Balance

AbstractCircuitry 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: PCs preferentially inhibit mGluR1-expressing UBCs that respond to mossy fiber 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 GABAA receptors (GABAARs) and inhibit almost all mGluR1-expressing UBCs by activating GABABRs. PC to UBC synapses allow PC output to regulate the input layer of the cerebellar cortex in diverse ways. GABAAR-mediated feedback is fast, unreliable, noisy, and suited to linearizing input-output curves and decreasing gain. Slow GABABR-mediated inhibition allows elevated PC activity to sharpen the input-output transformation of UBCs, and allows dynamic inhibitory feedback of mGluR1-expressing UBCs.

scholarly journals Local Estrogen Synthesis Regulates Parallel Fiber–Purkinje Cell Neurotransmission Within the Cerebellar Cortex

Endocrinology ◽  
2018 ◽  
Vol 159 (3) ◽  
pp. 1328-1338 ◽  
Author(s):  
Valerie L Hedges ◽  
Gang Chen ◽  
Lei Yu ◽  
Amanda A Krentzel ◽  
Joseph R Starrett ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Cerebellar Cortex ◽  
Metabotropic Glutamate Receptor ◽  
Receptor Activation ◽  
Parallel Fiber ◽  
Aromatase Activity ◽  
Glutamatergic Neurotransmission ◽  
Metabotropic Glutamate ◽  
Estrogen Synthesis ◽  
Glutamatergic Signaling

Abstract Estrogens affect cerebellar activity and cerebellum-based behaviors. Within the adult rodent cerebellum, the best-characterized action of estradiol is to enhance glutamatergic signaling. However, the mechanisms by which estradiol promotes glutamatergic neurotransmission remain unknown. Within the mouse cerebellum, we found that estrogen receptor activation of metabotropic glutamate receptor type 1a strongly enhances neurotransmission at the parallel fiber–Purkinje cell synapse. The blockade of local estrogen synthesis within the cerebellum results in a diminution of glutamatergic neurotransmission. Correspondingly, decreased estrogen availability via gonadectomy or blockade of aromatase activity negatively affects locomotor performance. These data indicate that locally derived, and not just gonad-derived, estrogens affect cerebellar physiology and function. In addition, estrogens were found to facilitate parallel fiber–Purkinje cell synaptic transmission in both sexes. As such, the actions of estradiol to support cerebellar neurotransmission and cerebellum-based behaviors might be fundamental to understanding the normal processing of activity within the cerebellar cortex.

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