alpha 2-adrenoceptor-mediated hyperpolarization of locus coeruleus neurons: intracellular studies in vivo.
Intracellular recordings in vivo from noradrenergic neurons in the rat locus coeruleus showed that membrane potential was hyperpolarized by the administration of clonidine (an alpha 2-adrenoceptor agonist) or after a burst of spikes evoked by intracellular pulses; both types of hyperpolarization were associated with a decrease in membrane input resistance, and both could be blocked by the alpha 2-adrenoceptor antagonist piperoxane. These results suggest that a hyperpolarization of membrane potential mediated by an alpha 2-adrenoceptor underlies both clonidine- and activation-induced inhibition of locus coeruleus cell firing.
D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D008125:Locus Coeruleus / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D010883:Piperoxan / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects
D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D010883:Piperoxan; D003000:Clonidine