Fig. 1.

Distribution of all recorded Purkinje cells (PCs) in relation to the occurrence of long simple spike (SS) pauses. A: we performed extracellular recordings of PC activity from awake C57Bl/6 mice at rest. After each recording, the recording site was marked by a small injection of Alcian Blue. B: the location of the craniotomy was varied to be able to obtain PCs from different parts of the cerebellum at different recording depths. C: after histological processing or imaging, the location of 288 cells was successfully determined. The locations of all recording sites were projected on the mediolaterally nearest of five sagittal sections [schematic drawings were adapted from Franklin and Paxinos atlas (Paxinos and Franklin 2001) with permission]. PCs were subdivided based on the presence of a “long” pause in the recording, i.e., the occurrence of at least one interspike interval (ISI) with a duration of 500 ms (cells with long pause, orange, n = 31; without, black, n = 257). Note that the recordings obtained in combination with 2-photon imaging (n = 17) are located in the superficial layer of lobules IV-V, VI, and Crus I. D: example traces of PC recordings without (top) and with (bottom) long pauses; complex spikes are marked by asterisks (*). E: PCs with long pauses on average have a lower SS firing rate and higher CV. Error bars represent SE. **P < 0.01.