Abstract
To study the possible mechanism through which honokiol and magnolol elicit their central
depressant effects, we examined the influence of these two phenolic compounds on 25
mM K+-stimulated release of [3
H]acetylcholine (ACh) from the rat's hippocampal slices. Honokiol, but not magnolol,
elicited a concentration-dependent enhancement of K+-evoked ACh release. Addition of either tetrodotoxin, pilocarpine, or methoctramine
had no effect on honokiol-enhanced ACh release. These results suggest that honokiol
enhanced K+-evoked ACh release directly on hippocampal cholinergic terminals via receptors other
than the M2 cholinergic subtypes.
