serotonin
Tryptophan Hydroxylase
PCPA methyl ester hydrochloride (250-500 mg/kg; oral administration; daily; for 8 weeks) treatment significantly decreases serotonin levels in both hippocampus and cortex. In C57BL/6 elite male mice, 5-HT levels decreased by 85% and 55% in the hippocampus of mice treated with oral or ip PCPA methyl ester hydrochloride, respectively, whereas in the prefrontal cortex, 5-HT levels decreased by 65% (oral) and 50% (ip).