Theta-patterned tactile stimulation modifies deep cerebellar nuclei neurons responsiveness in vivo

Several forms of synaptic plasticity have been described in the cerebellar network in vitro, but how plasticity may be induced in vivo remains poorly explored. Sensory tactile stimuli organized in theta patterns have been reported to induce long-term changes in cerebellar granule cells (Roggeri et al., 2008), Purkinje cells and molecular layer interneurons (Ramakrishnan et al., 2016) in vivo. Deep cerebellar nuclei (DCN) neurons are known to respond to low frequency sensory stimulation through typical discharge patterns reflecting the inhibitory and excitatory inputs converging onto these nuclei, provided by Purkinje cells and mossy fibers respectively (Rowland and Jaeger, 2008). Nevertheless, whether and how DCN are able to modify their discharges following theta-patterned sensory stimulation remains unexplored. Herein, we addressed this issue performing single-unit recordings in vivo, from the medial nucleus of anesthetized mice. Our results provide the first evidence that DCN neurons are indeed able to modify their discharge properties following sensory stimulation in vivo, completing the picture of the theta sensory stimulation (TSS) impact on cerebellar neurons discharge in vivo