> Thank you! Sigh, more reading.
>> For others following the discussion, the other incredible thing in the
> retina is that signalling is done by switching OFF the stream of
> transmitter coming from the rods and the cones. So a detectable burst
> of light produces a temporary stop in the outflow of glutamate, and this
> pause in secretion is what we actually detect as the basis for visual
> stimuli!
>> Show you how quickly the glial cells scavenge the glutamate from the
> cleft - and why vision is actually the slowest of the senses in terms of
> the briefest detectable stimulus.
And probably why the receptors are the most metabolically demanding.