Abstract
Stimulation of the Schaffer collateral projection to the CA1 region in rat hippocampal slices at 1 Hz for 15 min produced a N-methyl-D-aspartate (NMDA) receptor-dependent long-term depression (LTD) of synaptic responses and, when given after tetanic stimulation, reversed long-term potentiation (LTP). Both LTD and the reversal of LTP were blocked by the nitric oxide (NO) inhibitor L-N(G)-monomethylarginine (L-NMMA). L-N(G)-nitroarginine (L-NOArg) and hemoglobin also blocked LTD. The inhibition of LTD by L-NMMA was overcome by L- but not D-arginine. Sodium nitroprusside and S-nitrosocysteine, agents that spontaneously release NO, mimicked the effect of 1 Hz stimulation. These results indicate that NO mediates LTD produced by sustained 1 Hz activation of CA1 synapses and support the hypothesis that NO mediates the inhibition of LTP produced by untimely activation of NMDA receptors.
| Original language | English |
|---|---|
| Pages (from-to) | 1131-1134 |
| Number of pages | 4 |
| Journal | NeuroReport |
| Volume | 4 |
| Issue number | 9 |
| State | Published - 1993 |
Keywords
- N-methyl-D-aspartate
- carbon monoxide
- hippocampus
- long-term depression
- long-term potentiation
- nitric oxide