title: Voltage-dependent P/Q-type calcium channels at the frog neuromuscular junction.
abstract: It is well known that antagonists of N-type voltage-gated calcium channels inhibit the evoked quantal release of acetylcholine in amphibian neuromuscular synapses. This, however, does not exclude the functional expression of other types of voltage-gated calcium channels in these nerve terminals. Using immunocytochemistry, we detected the expression of the alpha1A subunit of P/Q-type calcium channels (that is otherwise typical of mammalian motor nerve endings) in the frog neuromuscular junction. In addition, we demonstrated that the P/Q-type channel blocker omega-agatoxin IVA (20 nM) reduced the action potential-induced calcium transient and significantly decreased both spontaneous and evoked mediator release. Our data indicates the functional expression of P/Q-type calcium channels in the frog motor nerve ending which participate in acetylcholine release.
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, Kazan, Russia.
authors.forename: L F
authors.initials: LF
authors.lastname: Nurullin
authors.forename: A R
authors.initials: AR
authors.lastname: Mukhitov
authors.forename: A N
authors.initials: AN
authors.lastname: Tsentsevytsky
authors.forename: N V
authors.initials: NV
authors.lastname: Petrova
authors.forename: D V
authors.initials: DV
authors.lastname: Samigullin
authors.forename: A I
authors.initials: AI
authors.lastname: Malomouzh
authors.forename: E A
authors.initials: EA
authors.lastname: Bukharaeva
authors.forename: F
authors.initials: F
authors.lastname: Vyskočil
authors.forename: E E
authors.initials: EE
authors.lastname: Nikolsky
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology*; D011895:Rana ridibunda; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D002118:Calcium