Mechanical Dissociation of Retinal Neurons with Vibration

摘要

Neuromorphic devices that implement the functions of biological neural circuits by means of VLSI technology have been attracting gre.it attention in engineering fields in the last decade. Concurrently, progress in neuroscience research has demonstrated nonlinear computations at the single neuron level, suggesting that individual neurons are not merely passive circuit elements but computational units. Thus, elucidating the properties of neuronal signal processing is an essential step in developing the next generation of neuromorphic devices. In this study, we developed a method of dissociating single neurons from specific sublayers of mammalian retinas without using proteolytic enzymes, instead combining tissue incubation in a low-Ca~(2+) medium with a vibrodissociation technique previously developed for slices of brain and spinal cord. Our method takes less time and requires less manual skill than in the conventional enzymatic method, but yields a sufficient number of cells usable for acute electrophysiological experiments. Single retinal neurons dissociated by our method are useful for measuring nonlinear membrane conductances as well as spike firing properties in the perforated-patch whole-cell configuration. These neurons also enable us to investigate the effects of proteolytic enzymes on membrane excitability in such cells.