Whole-cell current clamp paired recording from 2 External Tufted cells filled with biocytin and reconstructed using NeuroLucida software (middle right panel). First panel shows a sample of 5 sec recording of membrane potentials: the blue and red superimposed traces correspond to recording from the 2 neurons drawn in red and blue, respectively. Note that the 2 neurons fire bursts of action potential either together or alone. The 2 neurons exhibited highly synchronous membrane potential oscillations and bursting as also indicated by the cross-correlogram. The coefficient of correlation at zero time lag was C = 0.56