Microfluidic culture platform for neuroscience research

This protocol describes the fabrication and use of a microfluidic device to culture central nervous system (CNS) and peripheral nervous system neurons for neuroscience applications. This method uses replica-molded transparent polymer parts to create miniature multi-compartment cell culture platforms. The compartments are made of tiny channels with dimensions of tens to hundreds of micrometers that are large enough to culture a few thousand cells in well-controlled microenvironments. The compartments for axon and somata are separated by a physical partition that has a number of embedded micrometer-sized grooves. After 3-4 days in vitro (DIV), cells that are plated into the somal compartment have axons that extend across the barrier through the microgrooves. The culture platform is compatible with microscopy methods such as phase contrast, differential interference microscopy, fluorescence and confocal microscopy. Cells can be cultured for 2-3 weeks within the device, after which they can be fixed and stained for immunocytochemistry. Axonal and somal compartments can be maintained fluidically isolated from each other by using a small hydrostatic pressure difference; this feature can be used to localize soluble insults to one compartment for up to 20 h after each medium change. Fluidic isolation enables collection of pure axonal fraction and biochemical analysis by PCR. The microfluidic device provides a highly adaptable platform for neuroscience research and may find applications in modeling CNS injury and neurodegeneration. This protocol can be completed in 1-2 days.