Fig. 3.
Ih is inhibited by IFN-γ in neocortical layer 5 neurons. a After 10 min, 1000 IU ml−1 IFN-γ decreased maximum amplitude of Ih and slowed its activation and deactivation as exemplified by traces of pharmacologically isolated and offline leak subtracted Ih before (black) and upon (red) direct IFN-γ application. Ih was elicited by the voltage step shown at the bottom. b IFN-γ reduced the Ih amplitude in all investigated neurons. c For the graph steady-state activation, curves were constructed from average relative tail currents (SEM given as bars) upon returning to − 65 mV from Ih activation, plotted against preceding activating voltages before (black) and after the application of IFN-γ (red). Fits of Boltzmann function are superimposed. Note that V1/2 after IFN-γ is depolarized and cannot explain the decrease in maximum Ih. d Application of IFN-γ decelerated the fast component of activation (quantified by an increase of τfast, left) and Ih deactivation as indicated by increased deactivation times (right). Rs remained constant (Rs-ctrl 9.7 ± 0.7 MΩ vs. Rs-IFN-γ 10.0 ± 0.7 MΩ, n = 16; P = 0.3, paired t test) throughout the experiments. Average age of animals for this series of experiments P35.6 ± 11.0