Characteristics of Light-evoked Retinal Ganglion Cell Activity with Postnatal Maturation in SD Rat / 의학물리

ABSTRACT

As part of Korean retinal prosthesis project, we have provided preliminary experimental results regarding voltage parameters for the stimulation of chemically degenerated rabbit retina. Since our APB-treated chemically degenerated retina is only ON-pathway blocked, now we switch our experiments to more appropriate retinal degeneration model, genetically degenerated retina model (RD mouse: rd/rd (C3H/HeJ)). Before studying with RD mouse, we started control experiments with normal SD rat to understand characteristics of retinal ganglion cell activity with postnatal maturation in rodents. Ganglion cell activities were recorded with 8x8 multi-electrode array. Moving spontaneous bursts appeared until postnatal day of 15. During pre-eye opening period, no light evoked response appeared. After postnatal day of 2 weeks (post-eye opening period), ON-, OFF- and ON/OFF response appeared. The fractional distributions of ON, OFF, and ON/OFF ganglion cell is about 40%, 50%, and 5%. The percentage (%) of light evoked response in each dorso-temporal, ventral, and dorso-nasal area of eye is about 50%, 37.5% and 12.5%, respectively. We concluded that the optimal period for experiment in rodent is about postnatal day of 2~3 weeks.