Reading the clock: how Purkinje cells decode the phase of olivary oscillations

Climbing fiber responses in cerebellar Purkinje cells are described as being invariant. In this issue of Neuron, Mathy et al. show that the complex spike waveform changes with the number of spikes in a climbing fiber burst, which depends on the phase of olivary oscillations. In turn, different complex spike profiles affect synaptic plasticity at parallel fiber synapses. Thus, information on inferior olive oscillation states is reflected in both the complex spike waveform and the parallel fiber input gain.