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Synaptic Specializations Support Frequency-Independent Purkinje Cell Output from the Cerebellar Cortex.

ABSTRACT: The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells (PCs). Here, we characterize the properties of the PC-DCN synapse in juvenile and adult mice and find that prolonged high-frequency stimulation leads to steady-state responses that become increasingly frequency independent within the physiological firing range of PCs in older animals, resulting in a linear relationship between charge transfer and activation frequency. We used a low-affinity antagonist to show that GABAA-receptor saturation occurs at this synapse but does not underlie frequency-invariant transmission. We propose that PC-DCN synapses have two components of release: one prominent early in trains and another specialized to maintain transmission during prolonged activation. Short-term facilitation offsets partial vesicle depletion to produce frequency-independent transmission.

SUBMITTER: Turecek J

PROVIDER: S-EPMC5870134 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature

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Synaptic Specializations Support Frequency-Independent Purkinje Cell Output from the Cerebellar Cortex.

Turecek Josef J Jackman Skyler L SL Regehr Wade G WG

Cell reports 20161201 12

The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells (PCs). Here, we characterize the properties of the PC-DCN synapse in juvenile and adult mice and find that prolonged high-frequency stimulation leads to steady-state responses that become increasingly frequency independent within the physiological firing range of PCs in older animals, resulting in a linear relationship between charge transfer and activation frequency. We used a low-affinity anta ...[more]

PMID: 28009294

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