Many theories of cerebellar function assume that long-term depression (LTD) of parallel fiber (PF) synapses enables Purkinje cells to learn to recognize PF activity patterns. We have studied the LTD-based recognition of PF patterns in a biophysically realistic Purkinje-cell model. With simple-spike firing as observed in vivo, the presentation of a pattern resulted in a burst of spikes followed by a pause. Surprisingly, the best criterion to distinguish learned patterns was the duration of this pause. Moreover, our simulations predicted that learned patterns elicited shorter pauses, thus increasing Purkinje-cell output. We tested this prediction in Purkinje-cell recordings both in vitro and in vivo. In vitro, we found a shortening of pauses when decreasing the number of active PFs or after inducing LTD. In vivo, we observed longer pauses in LTD-deficient mice. Our results suggest a novel form of neural coding in the cerebellar cortex.

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Erasmus MC: University Medical Center Rotterdam

Steuber, V., Mittmann, W., Hoebeek, F., Silver, A., de Zeeuw, C., Häusser, M., & de Schutter, E. (2007). Cerebellar LTD and Pattern Recognition by Purkinje Cells. Neuron, 54(1), 121–136. doi:10.1016/j.neuron.2007.03.015