Sahu et al. STORM Data

Sodium and potassium channels that regulate axonal spike propagation are highly organized at nodes of Ranvier by a spectrin-actin membrane periodic skeleton. STORM-TIRF microscopy was used to define the spatial organization over the soma of a complex of Cav1.3 calcium, RyR2, and IK potassium channels (CaRyK) that generate a slow AHP in hippocampal neurons. Nearest neighbor distance and non-negative matrix factorization analyses identified two spatial patterns as linear rows of 3-8 immunolabeled clusters with 155 nm periodicity that extended to branchpoints, or as isolated clusters with 600-800 nm separation. The same patterns were detected for spectrin βII and the actin linking proteins actinin I and II that substantially overlapped with CaRyK complex clusters. The data reveal a close correspondence between CaRyK complex proteins and a net-like structure of spectrin βII across the soma that coordinates the spatial organization of channels that control the pattern of spike output.