Intracellularly injected inositol 1,3,4,5,6-pentakisphosphate induces a slow inward current in identified neurons of Aplysia kurodai.
Micropressure injection of inositol 1,3,4,5,6-pentakisphosphate (IP5) into identified neurons (R9-R12) of Aplysia induced a slow inward current associated with a conductance increase. The IP5-induced inward current was decreased by depolarization and increased by hyperpolarization. The extrapolated reversal potential of the current was -11 mV. The IP5-induced inward current was sensitive to changes in [Na+]o, [Ca2+]o and [K+]o but not to changes in [C1-]o, and was resistant to tetrodotoxin. The current was not completely abolished by Ca2+ channel blocking cations, Co2+ and Mn2+. Ion substitution and pharmacological experiments suggest that microinjection of IP5 can activate a non-specific cation conductance in Aplysia neurons.
Sawada
M
M
Department of Physiology, Shimane Medical University, Izumo, Japan.
Ichinose
M
M
Maeno
T
T
D000818:Animals; D001048:Aplysia / Q000502:physiology*; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*
D007295:Inositol Phosphates; C013571:inositol pentaphosphate