Alzheimerâs Deficits in Neurogenesis and Memory Lessened by Small Molecule Alzheimer's disease. [National Institute on Aging/National Institutes of Health] May 26, 2021 Share Brains devastated by Alzheimerâs disease (AD) can be ârejuvenatedâ by restoring the expression of a microRNA molecule, report scientists based at the Leuven Brain Institute and the Netherlands Institute for Neuroscience (NIN). The molecule, miR-132, is one of the most consistently downregulated microRNAs in AD. According to the scientists, miR-132 loss in AD inhibits the generation of new neurons at the hippocampus, where memories are initially formed. The scientists added, however, that miR-132 supplementation can facilitate the generation of new neurons, and thereby alleviate memory deficits in AD.