Activators of G-proteins increase the plasticity of cholinoreceptors of common snail neurons.
The influences of depth of damping of the inward current evoked by acetylcholine (the ACh-current), of two nonhydrolyzable analogs of GTP, which irreversibly activate G-proteins, namely 5'-guanylylimidodiphosphate (Gpp(NH)p) and guanosine 5'-O-(3-thiotriphosphate) (GTP-g-S), were investigated in identified RPa3 and LPa3 neurons of the common snail using the two-electrode voltage clamp technique. An irreversible deepening of the damping of the ACh-current following intracellular iontophoretic injections (-2 nA, 10 min) of Gpp(NH)p and GTP-g-S was demonstrated. A conclusion was reached regarding the participation of G-proteins in the molecular mechanism of the positive regulation of plasticity of cholinoreceptor neurons. Both of the G-protein activators used demonstrated a new atypical influence on the damping of the ACh-current, a disruption of its monotonic character. The hypothesis is advanced that the cause of such an influence lies in the oscillations of the concentration of intracellular Ca2+ induced by G-protein activators.
Pivovarov
A S
AS
M. V. Lomonosov Moscow State University.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001711:Biotransformation / Q000187:drug effects; D019204:GTP-Binding Proteins / Q000378:metabolism*; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000502:physiology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006372:Helix, Snails / Q000502:physiology*; D066298:In Vitro Techniques; D007478:Iontophoresis; D008564:Membrane Potentials / Q000187:drug effects; D009473:Neuronal Plasticity / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D011950:Receptors, Cholinergic / Q000187:drug effects*
D011950:Receptors, Cholinergic; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D019204:GTP-Binding Proteins; D000109:Acetylcholine