Reversed ethanol effects on potassium conductances in aged hippocampal dentate granule neurons.
The effect of low dose (20 mM) ethanol superfusion on the membrane and synaptic properties of dentate granule neurons was studied in hippocampal slices from young-mature (6-8 months) and old (25-29 months) Fischer-344 rats. In young neurons, ethanol hyperpolarized the resting membrane potential (RMP) and prolonged the post-spike train afterhyperpolarization (AHP). By contrast, ethanol depolarized old neurons and decreased their AHPs, in addition to reducing IPSP amplitudes and spike frequency adaptation. These effects can be explained by ethanol-enhancing potassium conductance (gK) in young neurons and diminishing gK in old neurons.
Niesen
C E
CE
Playfair Neuroscience Unit, Toronto Western Hospital, Ont., Canada.
Baskys
A
A
Carlen
P L
PL
D000200:Action Potentials / Q000187:drug effects; D000375:Aging; D000818:Animals; D000431:Ethanol / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344
D000431:Ethanol; D011188:Potassium