Evidence for a catecholamine-mediated slow hyperpolarizing synaptic response in parasympathetic ganglia.
Stimulation of preganglionic nerve trunks in the presence of muscarinic and nicotinic cholinoceptor and purinoceptor antagonists produced a slow-hyperpolarizing synaptic potential that was mimicked by exogenously applied norepinephrine. Both responses were blocked by yohimbine, an alpha-adrenoceptor antagonist, and enhanced by imipramine and cocaine, inhibitors of norepinephrine reuptake. These findings fulfill pharmacological criteria suggesting that norepinephrine is a neurotransmitter in cat bladder parasympathetic ganglia.
D000320:Adrenergic Fibers / Q000502:physiology; D000818:Animals; D002395:Catecholamines / Q000502:physiology*; D002415:Cats; D005071:Evoked Potentials; D005726:Ganglia, Parasympathetic / Q000502:physiology*; D009638:Norepinephrine / Q000502:physiology; D009435:Synaptic Transmission; D001743:Urinary Bladder / Q000294:innervation*
D002395:Catecholamines; D009638:Norepinephrine