“…These short-term (i.e., <1 wk) cultures have limited capacity to generate robust networks since in vitro cultures take weeks (>21 days) to fully develop mature axon connections (Dichter., 1978, Brewer et al, 1993). For these reasons, microfluidic structures such as microchannels (or tunnels) for the physical isolation of neuronal cells have been intensively investigated to generate long-term cultured neural networks (Claverol-Tinture and Pine., 2002, Bani-Yaghoub et al, 2005, Morin et al, 2005, Ravula et al, 2006, Dworak and Wheeler., 2009). While much progress has been made, the short distance of axons (≤500 μm) in these small neural circuits are not ideal for axon tract accessibility.…”