Large-scale microfluidic gradient arrays reveal axon guidance behaviors in hippocampal neurons

摘要

A large-scale microfluidic array has uncovered how chemical concentration gradients can manipulate delicate mammalian neurons. Although researchers agree that diffusible proteins direct nerve cells to grow and migrate using narrow projections known as axons, observing these effects with conventional micropipette experiments is difficult and time-consuming. To simplify such measurements, a team led by Nirveek Bhattacharjee and Albert Folch at the University of Washington, United States, fabricated a polydimethylsiloxane array of 1,024 microscale reservoirs containing molded microchannels that introduce fluids at controlled rates and create identical concentration gradients of a signaling protein in each reservoir. After seeding the chambers with single hippocampal neurons, the team tracked the growth dynamics of the cells using time-lapse microscopy. High-throughput analysis of hundreds of such neurons revealed that axons grow towards the source under high concentrations of a signaling protein but turn away from it at lower concentrations.