Conduction velocities in single fibers of the visual radiation

The population response predicted by the observations of this sample agrees well with those recorded by macroelectrodes for the cases of both antidromic and orthodromic propagation.

Abstract

Abstract Antidromic activation of a unit in the dorsal nucleus of the lateral geniculate body is defined as a response which follows stimulation in the striate cortex with a latency less than 0.8 msec or which exhibits both of the following characteristics: constant latency throughout the period of observation for all suprathreshold stimulus intensities; and continuous, inverse relationship between the latency of the response to the second of two equal stimuli and the time interval between the two stimuli at small values of the interval. Conduction velocities of antidromic spike propagation in seventy-three such units were found to occupy the range between 8 and 100 m/sec with relatively dense distributions at 18, 33 to 40, and 67 m/sec. Reasons are given for the conclusion that most, if not all, of these units projected to the striate cortex in the posterior portion of the lateral gyrus. The population response predicted by the observations of this sample agrees well with those recorded by macroelectrodes for the cases of both antidromic and orthodromic propagation.