(A) Top, deprivation and drug administration timeline. Bottom, D-row whisker deprivation and positioning of stimulating and recording electrodes in the S1 brain slice. X denotes the deprived D whisker column. (B) Representative paired pulse recordings at the L4-L2/3 synapse in the D column of a control rat (“whiskers intact”), a D-row deprived rat, a D-row deprived rat that received daily vehicle injections, and a D-row deprived rat that received daily AM251 injections. Paired pulse intervals were 20, 40, and 80 ms (plotted superimposed). (C) Mean PPR at 40 ms ISI across the different experimental groups, showing results from deprived D and spared B columns within each slice. 7 d deprivation data are reprinted from Bender et al. (2006a).