Cycles of excitability in neurons of visual corter in waking rabbits in response to double flashes

Conclusion

• 1. By averaging neuron responses in the visual cortex to flashes, the following phases of excitability have been identified: a phase of unresponsiveness (40–80 msec), a phase of diminished excitability (80–130 mscc), a phase of increased excitability (130–200 msex) and return to normal (200–250 msec).

• 2. Excitability cycles are determined chiefly by the inhibitory pause in the neuron discharge.

• 3. The inhibition strength varies in different parts of this pause.

• 4. Excitability cycles differ from neuron to neuron; the peak of inhibition, and emergence from it do not coincide fully in different neurons. This distinction may facilitate a more rapid analysis of temporal parameters of a stimulus in the cortex and other structures.