An electronic market for trading of securities includes a plurality of client stations for entering quotes for securities and a server process. The exhaust gas particulate filter is arranged in an exhaust passage of an internal combustion engine for capturing particulate matter in exhaust gas from the internal combustion engine. Using a viral vector, the concentration of neurotrophin delivered as part of a neurotrophic composition varies from 1010 to 1015 neurotrophin encoding viral particlesml of composition fluid.