Figure 1.

Action potentials propagate throughout the dendritic arbor. A, Voltage-sensitive dye (VSD) fluorescence confocal z-projection of an LGNd interneuron. Colored boxes are regions of interest for optical recordings in B. B, Electrical and optical signals corresponding to three action potentials in a train initiated by a depolarizing step at the soma. Electrical and optical signals are an average of two trials. Black traces are somatic electrode recordings. Colored traces are optical signals (ΔF/F) acquired at 2 kHz in the dendrite. Colored traces correspond to colored boxed regions in A. Optical traces are normalized to peak amplitude.