Effects of GABA and diazepam on 3H-serotonin release from hippocampal synaptosomes.
The effects of GABA and diazepam on the spontaneous and potassium-evoked release of 3H-5-HT from rat hippocampal synaptosomes, preloaded by incubation with 3H-5-HT, have been investigated. Both GABA and diazepam independently increased the spontaneous release of 5-HT whereas they blocked the calcium-dependent, potassium-evoked release. However diazepam antagonised the GABA-mediated increase in spontaneous release but enhanced the inhibitory effects of GABA on potassium-stimulated release. The results suggest that 5-HT release in the hippocampus is under the presynaptic control of GABA and that diazepam may selectively enhance the inhibitory effect of GABA on the evoked release of 5-HT.
D000818:Animals; D003975:Diazepam / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D012701:Serotonin; D005680:gamma-Aminobutyric Acid; D003975:Diazepam