Gotow T, Nishi T, Murakami M
Department of Physiology, Faculty of Medicine, Kagoshima University, Japan.
Brain Res. 1997 Jan 16;745(1-2):303-8. doi: 10.1016/s0006-8993(96)01214-0.
The cGMP-activated K+ channels closed by light lead to the depolarizing photocurrent of photoreceptors in the Onchidium ganglion. Whole-cell current records showed that external application of 100-200 microM 4-aminopyridine or 200-400 microM l-cis-diltiazem completely blocked the macroscopic photocurrent at any depolarizing and hyperpolarizing potentials. Single-channel current recordings suggested that both 4-aminopyridine and l-cis-diltiazem act to block the cGMP-activated K+ channels in their open state from inside the cell.
