Human neural progenitors exposed to harmine, an alkaloid presented at the psychotropic plant decoction ayahuasca, led to a 70 percent increase in proliferation of these cells. The effect of generating new human neural cells involves the inhibition of DYRK1A, a gene that is over activated in patients with Down syndrome and Alzheimer’s Disease. Thus harmine could have a potential neurogenesis role and possibly a therapeutic one over cognitive deficits.