Suppression of long-term potentiation in hippocampal slices by copper

✍ Scribed by Nanuli Doreulee; Yevgenji Yanovsky; Helmut L. Haas

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 96 KB
• Volume: 7
• Category: Article
• ISSN: 1050-9631
• DOI: 10.1002/(sici)1098-1063(1997)7:6<666::aid-hipo8>3.0.co;2-c

✦ Synopsis

Cu 2؉ -ions are known to interfere with ␥-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 Cu 2؉ in the CA 1 region of hippocampal slices. Field excitatory postsynaptic potential (EPSP) slopes in the CA1 region were unaffected by 1 M Cu 2؉ but were depressed by 10 M (to 85%) and 100 M (to 50%). A paired-pulse test revealed no difference in facilitation in the presence or absence of Cu 2؉ , indicating a postsynaptic action. A late component of intracellularly registered EPSPs in Mg 2؉ -free solution was also reduced by Cu 2ϩ . 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 M and to 50% of control by 10 M Cu 2؉ . Long-term potentiation, evoked by 3 ؋ 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 M Cu 2؉ in the bath. Thus low concentrations of copper can selectively reduce NMDA-mediated potentials and synaptic plasticity.