Song notes that parvalbumin-expressing interneurons have been found by others to behave abnormally in neurodegenerative diseases such as Alzheimer???s and mental illnesses such as schizophrenia. ???Now we want to see what the role of these interneurons is in the newborn neurons??? next steps: migrating to the right place and integrating into the existing circuitry,??? he says. ???That may be the k