Raman Lab Sheds New Light on Sensorimotor Mechanisms
March 25, 2024
In the paper “Simple spike patterns and synaptic mechanisms encoding sensory and motor signals in Purkinje cells and the cerebellar nuclei” by Raman lab members Spencer Brown, Mauricio Medina, Meghana Holla, Chris Vaaga, and Indira Raman, the authors investigate how sensory and motor information are simultaneously but separately encoded in cerebellar Purkinje cells of awake mice. While motor commands associated with whisker movements produce slow modulations of simple spike rates, a tactile sensory stimulus to the whiskers generates a well-timed decrease in spike probability, yielding a short gap in firing that is synchronous across the population of Purkinje cells. The mechanism of this dual code lies in the different properties of short-term synaptic plasticity of excitatory and inhibitory synapses to Purkinje cells. The consequence is that targets of the Purkinje cells in the cerebellar nuclei can filter or ignore slow changes in inhibitory input associated with movement, but they respond strongly to synchronous disinhibition associated with sensory stimuli, setting the stage for corrective actions triggered by sensation. The paper was published in Neuron on March 15, 2024.