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

Abstract

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 Ca(2+) concentrations, the related neuronal genes and real-time Ca(2+) 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.

Microfluidic platforms for the study of neuronal injury in vitro

“…Following the primary insult after TBI or SCI, secondary damage, such as glutamate excitotoxicity, can greatly affect neuronal survival and activity (Neukomm & Freeman, ; Sharif‐Alhoseini et al, ). Microfluidic platforms can ascertain the effects of biochemical injury mechanisms on precise subcellular regions by precisely controlling the spatio‐temporal distribution of pharmacological agents (Li et al, ; Taylor & Jeon, ; Velve‐Casquillas et al, ). Typically, a detergent or neurotransmitter is used to damage neurons or simulate excitotoxicity (Lee et al, ) but other molecules such as hemolytic compounds and immunogenic compounds have been used to study mechanisms of neuronal damage (Kilinc et al, ; Li et al, ).…”

Investigation of nerve injury through microfluidic devices

“…Microfluidic platforms have been used as valuable tools to study axon regeneration in vivo. Many model organisms such as Aplysia californica, Caenorhabditis elegans, Drosophila and zebrafish have been used for in vivo neuron injury and regeneration studies [68,[71][72][73][75][76][77][78][79][80][81][82]. Caenorhabditis elegans in particular provides an interesting paradigm for studying nerve injury and regeneration as its genome has been completely sequenced, and in vivo axotomy for the organism is feasible.…”

Preparation of Neuronal Co-cultures with Single Cell Precision

“…The Campenot chamber 1,2 and more recently microfabricated embodiments 3,4 can be used for the ex vivo preparation of networked neuronal co-cultures with the ability to selectively perturb the different somatic populations and also their neurite outgrowths. These microfluidic devices have for example been used to study axon degeneration and regeneration following chemical 5,6 or laser axotomy [6][7][8] , tauopathy 9 , viral dissemination 10,11 , and mRNA localization in axons 4 .…”