George S A, Mastronarde D N, Dubin M W
Brain Res. 1984 Jun 18;304(1):121-6. doi: 10.1016/0006-8993(84)90867-9.
Under normal visual stimulation, simultaneous recording from ganglion cells in the retina and from the axons of these cells in the brain revealed activity-dependent differences in the velocity of impulse propagation. In frog ganglion cells, spikes initiated 5-500 ms after a previous impulse showed supernormal increases in conduction velocity of up to 17%; spikes initiated 500-2000 ms after a previous one traveled more slowly than a spike initiated after a long period of rest. Cat ganglion cell impulses showed much smaller supernormality (maximum 3%), but exhibited pronounced slowing due to refractoriness and long-term fatigue associated with their high levels of spontaneous activity.
