Amino alcohol modulation of hippocampal acetylcholine release

The synthesis and release of ³H-acetylcholine was measured in hippocampal slices of adult rat brain following acute in vitro exposure to ethanolamine. Evoked release of ³H-acetylcholine was elevated by 60-70% but ³H-acetylcholine synthesis was unaffected. Other amino alcohols were also found to significantly increase evoked ³H-acetylcholine release. The effect may be stereochemically mediated since only one of four possible propanolamine configurations, R-alaninol, was active. The most potent compound tested was R-prolinol which showed an EC₅₀ nearly 10-fold lower than that of either R-alaninol or ethanolamine; S-prolinol was inactive. Slices taken from adult rats which had been fed active compounds for two weeks also exhibited enhancements in evoked ³H-acetylcholine release. These results indicate that amino alcohols modulate acetylcholine release in the rat hippocampus.