Inclusion of the κ agonist U50488 in the perifusion medium enhanced K+-stimulated 5-HT release from ground squirrel hippocampal slices, but reduced 5-HT outflow in both young and old rats' hippocampal slices. The stimulatory effect of U50488 on 5-HT release from ground squirrel hippocampus was not significantly attenuated by the non-specific opioid antagonist naloxone (10-5 M), but was completely reversed by the specific κ antagonist nor-BNI (10-6 M), and the voltage-dependent sodium channel blocker TTX (10-6 M). In contrast, the inhibitory effect of U50488 on 5-HT release from the young rat hippocampus was attenuated by naloxone (10-6 M), but not by nor-BNI (10-6 M) or TTX (10-6 M). These results illustrate a significant species difference in the modulatory effect of opioids on neurotransmitter release in the hippocampus.
|Original language||English (US)|
|Number of pages||3|
|State||Published - Jul 4 1994|
- Serotonin release
- κ Opioid receptor
ASJC Scopus subject areas