Suppression of long-term potentiation in hippocampal slices by copper.
Cu(2+)-ions are known to interfere with gamma-aminobutyric acid (GABA)- and glutamate-operated ion channels from experiments with isolated neurons. Such actions are likely involved in the pathophysiology of Wilson's disease. We have now studied the effects of Cu2+ in the CA1 region of hippocampal slices. Field excitatory postsynaptic potential (EPSP) slopes in the CA1 region were unaffected by 1 microM Cu2+ but were depressed by 10 microM (to 85%) and 100 microM (to 50%). A paired-pulse test revealed no difference in facilitation in the presence or absence of Cu2+, indicating a postsynaptic action. A late component of intracellularly registered EPSPs in Mg(2+)-free solution was also reduced by Cu2+. The N-methyl-D-aspartate (NMDA) component of the field EPSP, isolated by adding CNQX and bicuculline in Mg(2+)-free solution, was reduced to 69% of control by 1 microM and to 50% of control by 10 microM Cu2+. Long-term potentiation, evoked by 3 x 50 pulses at 100 Hz, 20 s interval amounted to 132 +/- 11% 90 min after tetanization under control conditions but was absent in the presence of 1 microM Cu2+ in the bath. Thus low concentrations of copper can selectively reduce NMDA-mediated potentials and synaptic plasticity.
Doreulee
N
N
Institute of Physiology II, Heinrich-Heine-University, Düsseldorf, Germany.
Yanovsky
Y
Y
Haas
H L
HL
D000818:Animals; D002478:Cells, Cultured; D003300:Copper / Q000494:pharmacology*; D003864:Depression, Chemical; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects*; D008274:Magnesium / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism
D016194:Receptors, N-Methyl-D-Aspartate; D003300:Copper; D008274:Magnesium