Research on the physiological function of the rat retina with a multi-electrode array

Objective To investigate the physiological function of the isolated rat retina with a multi-electrode array (MEA) system,and develop a more comprehensive method to evaluate retinal function in animals.Methods In this experimental study,retinas were isolated from 6 Sprague-Dawley (SD) rats,and placed into the recording chamber with the ganglion cell layer facing the biochip electrode array.Retinas were perfused with aerated Ringer's solution for 15 minutes before recording.Then light-evoked or electrical current-evoked responses of the retinal cells were recorded with an MEA system.The obtained data were analyzed with a Shapiro-Wilk test,and the values were presented as a mean±standard deviation.Results Typical light-evoked responses were successfully recorded.The amplitude of the field potential became higher as the luminance increased (＜256 cd/cm2).The results also showed that the off-light responses were obtained when the duration of the light stimulus was changed from 6 to 10 seconds.The light-off response was a low amplitude negative wave at the offset of the light stimulus.Moreover,according to the peristimulus time histograms (PSTHs) and raster plots of individual units,the retinal ganglion cells (RGCs) were categorized as either ON,OFF,or ON-OFF.In addition,the responses of RGCs evoked by electrical current usually occurred within 50 ms post stimulus.Conclusion The MEA can be used to assess the retinal function of animals more comprehensively from different neurons (photoreceptor,bipolar cell and RGC). Key words: Multi-electrode recording; Electrophysiology,visual; Retina; Rats,Sprague-Dawley