Amblyopia and suppression in binocular cortical neurones of strabismic cat.

The neural mechanism of strabismic amblyopia was investigated by recording the spatio-temporal properties of striate cortical neurones of cats raised with a surgically induced esotropia. Multiple pseudo-random flashed or phase-alternating stimuli were used, and through cross-correlation, the Wiener kernels were extracted. This analysis has shown that in neurones which retain binocularity to adulthood, two different neural mechanisms of adaptation to ocular misalignment exist. Some of these neurones become amblyopic, such that the non-deviating eye dominates the response for high spatial frequencies while the strabismic eye dominates at low spatial frequencies. Other neurones adapt through active suppression of the monocular response to stimulation of the strabismic eye when the non-deviating eye is simultaneously stimulated.