Figure 3.

A reduction of the DAP and corresponding increase in AHP divide the FI relationship. A, Application of muscimol to the apical dendrites, whereas recording from dendrites (gray trace) reveals a reduction in the width at the base of the dendritic spike. B, This reduction in dendritic spike width by muscimol is correlated with a larger AHP (gray) relative to control conditions (black) in separate somatic recordings. C, In the compartmental model, the dendritic recording has a faster decay time at its base under “experimental” conditions (increased dendritic G_lk, gray) compared with control conditions (normal, black). D, An increase in dendritic leak (0.6 mS/cm²) leads to a larger AHP at the soma (gray) relative to the control model (black). E, Dendritic leak is sufficient in the model to replicate the gain changes seen experimentally after GABA_a activation. Increasing levels of dendritic leak (3 times, ▴; 5 times, ○) cause divisive effects in the FI relationship compared with control (▪). F, In contrast, increasing the somatic leak by 10 times (▴) or 20 times (○) causes purely subtractive shifts without noticeably affecting gain relative to control conditions (▪).