Novel form of long-term potentiation produced by a K+ channel blocker in the hippocampus.
Long-term potentiation (LTP) of synaptic transmission in the hippocampus is a widely studied model of memory processes. In the CA1 region, LTP is triggered by the entry of Ca2+ through N-methyl-D-aspartate (NMDA) receptor channels and maintained by the activation of Ca2(+)-sensitive intracellular messengers. We now report that in CA1, a transient block by tetraethylammonium of IC, IM and the delayed rectifier (IK) produces a Ca2(+)-dependent NMDA-independent form of LTP. Our results suggest that this new form of LTP (referred as to LTPK) is induced by a transient enhanced release of glutamate which generates a depolarization by way of the non-NMDA receptors and the consequent activation of voltage-dependent Ca2+ channels.
Aniksztejn
L
L
INSERM U29, Hôpital de Port-Royal, Paris, France.
Ben-Ari
Y
Y
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D007051:Ibotenic Acid / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology*; D013997:Time Factors; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D015220:Calcium Channels; D015221:Potassium Channels; D013757:Tetraethylammonium Compounds; D007051:Ibotenic Acid; D016202:N-Methylaspartate; D019789:Tetraethylammonium; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid