Alzheimer's Disease Puzzle: Delving into Pathogenesis Hypotheses Neuronal hyperexcitability in Alzheimer's disease: what are the drivers behind this aberrant phenotype? Translational Psychiatry Dihexa (also known as PNB 0408) is an experimental small molecule derived from angiotensin IV. It was engineered to cross the bloodbrain barrier and has shown synaptogenic effects in preclinical models. The often quoted D I H E X A is having a moment right now and I get why. When something gets labeled as brain repair or synapse growth, it spreads FAST especially in communities