Figure 5. Purkinje cell simple spike firing patterns transform from P7 to P14 in control mice and reflect altered maturation in P14 En1^Cre/+;Atoh1^fl/- mice.

(A) Schematic of in vivo Purkinje cell recordings in P7 control mouse. Top left: cerebellum with recording electrode. Top right: schematic with recording electrode extracellular to Purkinje cell body. Bottom: representative 15 s recording from a Purkinje cell, each large vertical line is an action potential. (B) Same as (A) For P14 control mouse. (C) Same as (A) for P14 En1^Cre/+;Atoh1^fl/- mouse. (D) and (E) Examples of frequency (interspike interval, ISI⁻¹) distributions of simple spike firing rate in a P14 Purkinje cell recorded in a control (D) and En1^Cre/+;Atoh1^fl/- (E) mouse. Blue line indicates the ‘frequency’ as calculate by the total number of simple spikes/recording time (spikes/s). Red lines indicate ‘frequency mode’ as the frequency most commonly observed in the frequency distribution. (F) Simple spike firing frequency (spikes/recording time). (G) Simple spike frequency mode (peak ISI⁻¹ distribution). (H) and (I) example recordings (25 s) from P14 Purkinje cells in control (H) and En1^Cre/+;Atoh1^fl/- (I) mouse. The top is the recording. Bottom is the firing frequency averaged over one second. (J) Simple spike CV (global firing irregularity). (K) Pause percentage (proportion of recording with ISI > five times average ISI). (L) and (M) Examples of auto-correlograms of the simple spike ISI in a P14 Purkinje cell recorded in a control (L) and En1^Cre/+;Atoh1^fl/- (M) mouse. (N) Simple spike rhythmicity index calculated based on auto-correlogram. (O) Simple spike CV2 (local firing irregularity). For F,G, J, K, N, and O, significance was determined using an ANOVA between the four control age groups and two En1^Cre/+;Atoh1^fl/- age groups followed by a Tukey-Kramer post-hoc analysis to assess differences between the groups. Significance was accepted at p<0.05. In the figure, the statistical significance between two groups is indicated as a line starting and ending above the two groups. Gray lines indicate differences within control groups of different ages and orange lines indicate differences between control and En1^Cre/+;Atoh1^fl/- groups. N/n-numbers: control: P7-8: n=22 cells from N=13 mice; control P9-10: n=30/N=12; control P11-12: n=35/N=11; control P13-14: n=32/N=14; En1^Cre/+;Atoh1^fl/- P10: n=15/N=3; En1^Cre/+;Atoh1^fl/- P14: n=15/N=6. The raw data and specific p-values for all the comparisons are presented in Figure 5—source data 1.

Figure 5—figure supplement 1. Simple spike distributions of single Purkinje cells.

Heatmap of frequency distribution of simple spike firing patterns in Purkinje cells of different ages in control and En1^Cre/+;Atoh1^fl/- mice.