Retinal synaptic regeneration via microfluidic guiding channels.

Ping-Jung Su,Kenji Yokoi,Lidong Qin,Yuki Saito,Kai Zhang,Xiaojun Xia,Haifa Shen,Zongbin Liu,Xin Han

doi:10.1038/srep13591

Abstract

In vitro culture of dissociated retinal neurons is an important model for investigating retinal synaptic regeneration (RSR) and exploring potentials in artificial retina. Here, retinal precursor cells were cultured in a microfluidic chip with multiple arrays of microchannels in order to reconstruct the retinal neuronal synapse. The cultured retinal cells were physically connected through microchannels. Activation of electric signal transduction by the cells through the microchannels was demonstrated by administration of glycinergic factors. In addition, an image-based analytical method was used to quantify the synaptic connections and to assess the kinetics of synaptic regeneration. The rate of RSR decreased significantly below 100 μM of inhibitor glycine and then approached to a relatively constant level at higher concentrations. Furthermore, RSR was enhanced by chemical stimulation with potassium chloride. Collectively, the microfluidic synaptic regeneration chip provides a novel tool for high-throughput investigation of RSR at the cellular level and may be useful in quality control of retinal precursor cell transplantation.

Highlights

Is an important approach to investigate retinal neuron communication
We have developed an retinal synaptic regeneration (RSR)-Chip to mimic retinal functions and regenerated retinal synaptic connections in a high-throughput manner
We have shown the regeneration of retinal synaptic connections in the chip and demonstrated that the oriented network of synapses inside the guiding microchannels is physiologically functional

Summary

Introduction

Is an important approach to investigate retinal neuron communication. It is difficult to mimic the layered retinal structure, delineate the topologic effect, control the direction of synapses, and quantify changes in synaptic connectivity. To the best of our knowledge, no study has reported synaptic regeneration of retinal neurons using microfabricated channels with geometric guidance. We hypothesize that the designed microchannels might facilitate regeneration of the retinal synaptic connections and reconstruction of the in vivo functions. Multiple arrays of microchannels with the dimensions 50 or 100 μ m long, 3 or 4 μ m wide, and 17 μ m high were utilized to reconstruct the retinal neuronal synapse and form an organized network using R28 retinal precursor cells. We demonstrate that the synaptic connections of the precursor cells regenerated and formed a network of oriented synapses in the RSR-Chip. The effects of inhibitory and excitatory molecules on the dynamics of synaptic regeneration were assessed

Methods

Results

Discussion

Conclusion