Complex sentence: The low frequency drop-off is due to lateral inhibition within the retinal ganglion cells, a typical retinal ganglion cell presents a centre region with either excitation or inhibition and a surround region with the opposite sign.
Split into simpler sentences: The low frequency drop-off is due to lateral inhibition within the retinal ganglion cells. A typical retinal ganglion cell presents a centre region with either excitation or inhibition and a surround region with the opposite sign.