VIP and infection: As previously described, we successfully recorded responses in pyramidal cells following stimulation of MD inputs in the same slices from VIP interneurons that failed to respond to MD stimulation, and the amplitude of the interneuron and pyramidal cell responses was not significantly correlated (Supplementary Fig. 6), indicating that the differential response of PV and VIP cells to MD versus vHPC input did not reflect differences in infection or injection efficiency in the various preparations.