Figure 8.

Responses of SP and WM cells to plasticity induction protocol that pairs synaptic input at 0.1 Hz with direct depolarization (and spiking) of the postsynaptic cell. Schematic shows the organization of the pairing protocol used for LTP induction (for details, see Materials and Methods). Inset traces are examples of whether the recording was in voltage or current clamp and are not meant to represent a particular experiment. Arrow in the insets represents the location of extracellular stimulation. Gray bars indicate the conditioning period. Spike train represents the depolarization of the cell during the pairing. Representative examples from SP (A), showing significant depression, and WM (B), showing significant potentiation. Insets are average PSCs 10 min before pairing and from 30–40 min after conditioning (horizontal bars). C, D, Group data for all SP (n = 7) and WM (n = 9) cells in the sample, respectively. Significant depression (19%) was seen in SP cells (p < 0.001), but no change (3%) was seen in WM cells because some cells also showed mild potentiation.