Interestingly, tropisetron and ondansetron, another antiemetic drug with 5-HT3R antagonism, inhibited the 5-HT-mediated blockade of ACh release in the human cerebral cortex, thereby compensating for the impaired ACh neurotransmission observed in patients with AD and FTD.345. The gene discussed is HTR3A; the disease is Alzheimer disease.