Effects of noradrenaline on some potassium currents in CA1 neurones in rat hippocampal slices.
Pyramidal (CA1) cells in rat hippocampal slices were voltage clamped using a single electrode voltage clamp. In the presence of tetrodotoxin (TTX), depolarizing pulses from holding potentials of -60 to -70 mV elicited a slow inward calcium (Ca2+) current and two outward potassium (K+) currents: an A current and a slower, Ca2+-dependent K+ current. Noradrenaline (NA) (20 microM) depressed the amplitude of the K+ currents without affecting the Ca2+ current. The effect of NA could be blocked with propranolol and was mimicked by isoprenaline, suggesting that NA depresses the K+ currents by binding to beta-receptors.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000187:drug effects; D013779:Tetrodotoxin / Q000494:pharmacology
D011943:Receptors, Adrenergic, beta; D013779:Tetrodotoxin; D011433:Propranolol; D007545:Isoproterenol; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine