Figure 3.

Role of I_A current in repetitive firing in neurons in culture. (A) Application of a depolarizing current to isolated neurons in culture elicited repetitive firing of action potentials. Catechol blocked the repetitive firing. The membrane potential of the neuron was held at −80 mV. (B) Relationship between the current injected and the number of spikes evoked in the control and catechol (100 μM). (C) Catechol reversibly increased the amplitude of the first action potential and decreased that of the second action potential when it occurred. (D) The time to peak of the first action potentials was unaffected by catechol, whereas it was reversibly delayed for the second action potential. (E) The width of action potentials was reversibly increased by catechol. (F) The amplitude of the fAHP was reversibly reduced by catechol.