Somatostatin augments the M-current in hippocampal neurons.
Immunocytochemical and electrophysiological evidence suggests that somatostatin may be a transmitter in the hippocampus. To characterize the ionic mechanisms underlying somatostatin effects, voltage-clamp and current-clamp studies on single CA1 pyramidal neurons in the hippocampal slice preparation were performed. Both somatostatin-28 and somatostatin-14 elicited a steady outward current and selectively augmented the noninactivating, voltage-dependent outward potassium current known as the M-current. Since the muscarinic cholinergic agonists carbachol and muscarine antagonized this current, these results suggest a reciprocal regulation of the M-current by somatostatin and acetylcholine.
D000109:Acetylcholine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002586:Cesium / Q000494:pharmacology; D004553:Electric Conductivity; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials; D009116:Muscarine / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D013004:Somatostatin / Q000494:pharmacology*; D053561:Somatostatin-28
D002586:Cesium; D013004:Somatostatin; D053561:Somatostatin-28; D009116:Muscarine; D002217:Carbachol; D000109:Acetylcholine; D011188:Potassium