Muscarinic receptors mediating suppression of the M-current in guinea-pig olfactory cortex neurones may be of the M2-subtype.
Guinea-pig olfactory cortical neurones in vitro were voltage clamped by means of a single intracellular microelectrode technique. Hyperpolarizing voltage commands from holding potentials between -40 to -50 mV produced slow inward current relaxations reflecting deactivation of the M-current (IM). IM was reversibly suppressed by 30 microM muscarine or carbachol; this suppression was insensitive to pirenzepine (up to 300 nM) but was inhibited by gallamine (10-20 microM) or 4-diphenyl-acetoxy-N-methylpiperidine (100, 500 nM), suggesting the involvement of the M2-type muscarinic receptor.
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D005703:Gallamine Triethiodide / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009116:Muscarine / Q000502:physiology; D010880:Piperidines / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000145:classification* / Q000187:drug effects
D010880:Piperidines; D011976:Receptors, Muscarinic; D009116:Muscarine; C042375:4-diphenylacetoxy-1,1-dimethylpiperidinium; D005703:Gallamine Triethiodide