Fig. 7.

Bicuculline (20 μm) also potentiated the 4-AP-induced delayed depolarization in a microelectrode recording from a CA1 pyramidal neuron soma. Sixteen consecutive individual traces are shown in the top panels. They are averaged in thebottom panels to illustrate how temporal dispersion of the action potentials riding on the delayed depolarization can reduce their apparent amplitude. Such averaging may occur in the optical signals, which originate in many neurons simultaneously (see Fig. 5). The data presented are representative of three similar experiments.