Fig. 6.

Sequences of afterpotentials in different electrophysiological classes of pyramidal cells in monkey DLPFC. A–D: in the majority of pyramidal neurons, the first action potential in a train was followed by the same sequence of afterpotentials: a fast afterhyperpolarization (fAHP) was followed by a depolarizing afterpotential (ADP) and then by a medium afterhyperpolarization (mAHP). The ADP was generally more prominent in IM cells (C) than in RS cells (B); moreover, the ADP was undetectable in some RS neurons (A). In LTS cells, a prominent ADP led to the next spike, which completely masked a medium-component AHP (D). After the initial burst of spikes, LTS cells fired single spikes with the same sequence of afterpotentials as RS pyramidal cells. E: bar graph summarizing the measurements of amplitude of different components of AHP.