The actions of barbiturates on release of noradrenaline from rat hippocampal synaptosomes.

Barbiturates are believed to work both by augmenting GABA action and independently perhaps by decreasing neurotransmitter release. By studying the effect of pentobarbitates on the release of 3H noradrenaline from rat hippocampal synaptosomes it was found that pentobarbitone (10(-6)M and 10(-5)M) augmented the GABA evoked release of 3H noradrenaline but 10(-4)M depressed this GABA effect. This latter concentration of pentobarbitone also depressed the K+-evoked release of 3H noradrenaline by a Ca++ dependent but picrotoxin insensitive mechanism.