Pre-clinical work has led to a Phase I clinical trial starting in 2022 that is testing the efficacy of AAV2-BDNF gene therapy (stereotaxically administered to the EC-HPC under MRI guidance, as safe methods for targeting this circuitry have not yet been developed) for treating patients with MCI or AD (see clinicaltrial.gov identifier NCT05040217). Here, BDNF is linked to Alzheimer disease.