Y-29794 Tosylate is an orally active, potent and specific non-peptide prolyl endopeptidase (PPCE) inhibitor. Y-29794 selectively and competitively inhibited rat brain PPCE (Ki = 0.95 nM) in a reversible manner. Ex vivo study demonstrated that Y-29794 could penetrate into brain to exhibit dose-dependent and long-lasting inhibition. Furthermore, Y-29794 could potentiate the effect of TRH on the release of ACh in the rat hippocampus. Y-29794 prevents the progression of A beta-like deposition in the hippocampus of the SAM.