The effect of monocular paralysis on the lateral geniculate nucleus of the cat.

The proportions and some of the properties of X and Y cells in lateral geniculate nucleus (LGN) of adult cats were measured 14-16 days after monocular paralysis. The paralysis was produced by sectioning cranial nerves III, IV and VI. No difference from normal was observed in the proportions of X and Y cells either in the A layer driven by the paralyzed eye or in the A1 layer driven by the mobile eye. The distribution of latencies to chiasm stimulation and the average visual spatial resolution were within the normal range in both A and A1 layers. These experiments indicate that monocular paralysis in the adult cat does not affect the numbers of X and Y cells in the LGN. However, the averages of cell body size in layers A and A1 contralateral to the immobilized eye were roughly equal, whereas in the normal cat cells in layer A1 are larger than those in layer A.