Synaptic and intrinsic plasticity coordinate spike output in cerebellar Purkinje cells

Abstract

Learning has been thought to be implemented by activity-dependent modifications of synaptic weight and intrinsic excitability. Here, we highlight how long-term depression at parallel fiber to Purkinje cell synapses (PF-PC LTD) and intrinsic plasticity of PCs coordinate the postsynaptic spike discharge from C57BL/6 male mice. Intrinsic plasticity of PCs in the flocculus matched the timing rules and shared intracellular signaling for PF-PC LTD. Notably, the intrinsic plasticity was confined to the dendritic branches where the synaptic plasticity is formed. Besides, when either synaptic or intrinsic plasticity was impaired, the impact of PF inputs was less reflected by the spike output of PCs. In conclusion, synergies between synaptic and intrinsic plasticity may play a role in tuning the PC output, thereby achieving optimal ranges of output.

Intrinsic Plasticity of Cerebellar Purkinje Cells Contributes to Motor Memory Consolidation

“…We previously described that the concurrence of bidirectional synaptic and intrinsic plasticity may synergistically shape the cerebellar PC output (Shim et al, 2017). Most recently, synaptic LTD was found to be insufficiently reflected by spike output in STIM1 PKO mice because of lack of intrinsic plasticity, indicating that synergies between synaptic and intrinsic plasticity may play a critical role in determining the optimal ranges of PC output onto the downstream neurons (Shim and Kim, 2019). In this scenario, impairment of PC intrinsic plasticity shown in STIM1 PKO would break down the synergies between synaptic and intrinsic plasticity, thereby manifesting impairment of plasticity in VN neurons.…”