On the one hand, anatomical evidence suggests that a neuron has, on
average, on the order of THOUSANDS of neurons impinging on it. On the
other hand, physiological evidence shows that only a few epsps are
needed to generate an action potential - which would imply that ONE
cell is sufficient for exciting the postsynaptic neuron.
Can anyone explain this disparity between anatomy and physiology?
Some hypotheses:
1. most of the thousands of synapses on a neuron are inactive
(unlikely)
2. a neuron that has thousands of inputs has an extremely large and
finely-tuned range
If we knew what the range of a neuron is, on average, then we'd be
able to tell between the two above hypotheses.
-Doron