Spatiotemporally Controlled and Multifactor Involved Assay of Neuronal Compartment Regeneration after Chemical Injury in an Integrated Microfluidics

Studies on the degeneration and regeneration of neurons as individual compartments of axons or somata can provide critical information for the clinical therapy of nervous system diseases. A controllable in vitro platform for multiple purposes is key to such studies. In the present study, we describe an integrated microfluidic device designed for achieving localized stimulation to neuronal axons or somata. We observed neuronal compartment degeneration after localized chemical stimulation and regeneration under the accessorial function of an interesting compound treatment or coculture with desired cells in controllable chambers. In a spatiotemporally controlled manner, this device was used to investigate hippocampal neuronal soma and axon degeneration after acrylamide stimulation, as well as subsequent regeneration after treatment with the monosialoganglioside GM1 or with cocultured glial cells (astrocytes or Schwann cells). To gain insight into the molecular mechanisms that mediate neuronal injury and regeneration, as well as to investigate whether acrylamide stimulation to neurons induces changes in Ca2+ concentrations, the related neuronal genes and real-time Ca2+ signal in neurons were also analyzed. The results showed that neuronal axons were more resistant to acrylamide injury than neuronal somata. Under localized stimulation, axons had self-destruct programs different from somata, and somatic injury caused the secondary response of axon collapse. This study provides a foundation for future in-depth analyses of spatiotemporally controlled and multifactor neuronal compartment regeneration after various injuries. The microfluidic device is also useful in evaluating potential therapeutic strategies to treat chemical injuries involving the central nervous system.