Figure 5. Calcium current facilitation.

A) Ca²⁺ influx at the Calyx of Held evoked by a pair of 1 ms depolarizing steps (adapted from Cuttle et al. (1998)) and

B) action potentials (adapted from Di Guilmi et al. (2014)).

C) Paired-pulse facilitation of Ca²⁺ influx at different stimulus intervals produced by voltage steps at the Calyx of Held steps (adapted from(Cuttle et al., 1998)) and action potentials between cultured Purkinje cell synapses. Adapted from Diaz-Rojas et al. (2015).

D) The Ca²⁺ sensors NCS-1 and CaM bind to the IQ-like motif (IM) of P/Q-type Ca²⁺ channels to produce facilitation of Ca²⁺ entry. Substituting alanine for a pair of isoleucine and methionine residues in IM (IM-AA) disrupts this interaction.

E) EPSCs recorded from CA1 pyramidal cells in WT and IM-AA knockin mice. Recordings were made in the presence of ω-conotoxin GVIA to block N-type Ca²⁺ channels.

F) Paired-pulse facilitation in WT and IM-AA mice. (E) and (F) adapted from Nanou et al. (2016).