title: Use-dependent removal of the 4-aminopyridine-induced block of the transient K+ current in rat dorsal root ganglia.
abstract: Effects of 4-aminopyridine (4-AP) on the transient K(+) current (I(A)) was studied in rat sensory neurons using the whole cell patch-clamp technique. The amplitude of I(A) was reduced by 4-AP. The steady-state inactivation curve for I(A) was shifted in the positive direction by 4-AP, suggesting that the blocking action of 4-AP may be attenuated by membrane depolarization. When two I(A)s were evoked with variable intervals, the peak amplitude of the I(A) induced by the second pulse was augmented in the presence of 4-AP. These results indicate that the action of 4-AP can be modulated by concurrent neuronal activities.
authors.affiliation: Department of Neurophysiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ohishi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Matsutomi
authors.forename: Taixing
authors.initials: T
authors.lastname: Zheng
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kakimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Maruyama
authors.forename: Nobukuni
authors.initials: N
authors.lastname: Ogata
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D015761:4-Aminopyridine