AUTHOR=Ramakrishnan K. B. , Voges Kai , De Propris Licia , De Zeeuw Chris I. , D’Angelo Egidio TITLE=Tactile Stimulation Evokes Long-Lasting Potentiation of Purkinje Cell Discharge In Vivo JOURNAL=Frontiers in Cellular Neuroscience VOLUME=10 YEAR=2016 URL=https://www.frontiersin.org/journals/cellular-neuroscience/articles/10.3389/fncel.2016.00036 DOI=10.3389/fncel.2016.00036 ISSN=1662-5102 ABSTRACT=

In the cerebellar network, a precise relationship between plasticity and neuronal discharge has been predicted. However, the potential generation of persistent changes in Purkinje cell (PC) spike discharge as a consequence of plasticity following natural stimulation patterns has not been clearly determined. Here, we show that facial tactile stimuli organized in theta-patterns can induce stereotyped N-methyl-D-aspartate (NMDA) and gamma-aminobutyric acid (GABA-A) receptor-dependent changes in PCs and molecular layer interneurons (MLIs) firing: invariably, all PCs showed a long-lasting increase (Spike-Related Potentiation or SR-P) and MLIs a long-lasting decrease (Spike-Related Suppression or SR-S) in baseline activity and spike response probability. These observations suggests that tactile sensory stimulation engages multiple long-term plastic changes that are distributed along the mossy fiber-parallel fiber (MF-PF) pathway and operate synergistically to potentiate spike generation in PCs. In contrast, theta-pattern electrical stimulation (ES) of PFs indistinctly induced SR-P and SR-S both in PCs and MLIs, suggesting that tactile sensory stimulation preordinates plasticity upstream of the PF-PC synapse. All these effects occurred in the absence of complex spike changes, supporting the theoretical prediction that PC activity is potentiated when the MF-PF system is activated in the absence of conjunctive climbing fiber (CF) activity.