Fig. 3: FMRP reduces the availability of Cav3.1 and Kv4 current.

FMRP(1–297) (30 nM) was introduced by direct infusion through the electrode (a) and in (b) using separate cell populations with or without FMRP(1–297) in the electrode. FMRP(1–297) infusion for 10 min promotes a significant left-shift in Vh and Va of Cav3.1 (a) (Vh, p = 0.0021; Va, p = 0.02, both with paired-sample t test), and of the Vh of Kv4.3 (b) (Vh, p = 0.039, two-sample t test; Va, p = 0.346, paired-sample t test) when included in the electrode. Insets show superimposed recordings of current evoked by depolarizing to −30 from −70 mV (Cav3.1) (a) or −50 mV (Kv4.3) (b). c In granule cells of Fmr1 KO mice including 30 nM FMRP(1–297) in the electrode significantly left-shifts Kv4 Vh (p = 0.037 with two-sample t test) and reduces Kv4 current (inset). No effect was detected on Kv4 Va under these conditions. d Including 30 nM FMRP(1–297) in the electrode for Fmr1 KO granule cells induces a left-shift in Kv4 Vh in the presence of 1 µM TTA-P2 to block Cav3-mediated calcium influx (p = 0.008 with two-sample t test). Average values are mean ± s.e.m. and sample values at the base of plots in (c, d) indicate the number of cells drawn from 3 animals. *p < 0.05, **p < 0.01. Animals used in (c, d) were P16–22. GC granule cell. Source data are provided as a Source Data file.