Studies on the beneficial effects of yeast RNA treatment on learning and memory in senile patients and in animal experimentation are reviewed in this paper. Experimental evidence is cited showing that yeast RNA is not incorporated into brain tissue and does not increase brain synthetic activity. Thus the therapeutic effects of RNA treatment cannot be explained in direct relation to the hypothesis that RNA within the brain encodes memory information. Evidence for stimulant action of RNA, mediated by uric acid, its primary metabolite, is presented as the basis for an alternative theory which would explain RNA action in pharmacological terms.
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