Pharmacological evidence that somatostatin activates the m-current in hippocampal pyramidal neurons.
In the in vitro hippocampal slice somatostatin has been shown to cause a direct hyperpolarization of CA 1 pyramidal neurons by increasing a potassium conductance which is resistant to blockade by tetraethylammonium 4-aminopyridine, or cesium ions. Results reported here demonstrate that this somatostatin-induced hyperpolarization is blocked by 1 mM barium and 5 x 10(-5) M carbachol, with the action of carbachol being reversed by atropine. Barium and carbachol both inactivate the m-current and these results suggest that somatostatin may exert its hyperpolarizing action on CA1 pyramidal cells by activation of the m-current.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001464:Barium / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D051381:Rats; D013004:Somatostatin / Q000494:pharmacology*
D001464:Barium; D013004:Somatostatin; D001285:Atropine; D002217:Carbachol