Figure 10.

Monocularly deprived animals show a distinct developmental trajectory for receptor subunit expression. The PCA results are plotted in 3-dimensions to visualize the significant components for normal (yellow spheres) and monocularly deprived (red cubes) kittens in the (A) central, (B) peripheral, and (C) monocular visual field representation of visual cortex. The shadows projected on each of the three walls help to visualize the differences between normal (circles) and deprived (squares) kittens for each of the three components. Age (in weeks) is displayed beside each symbol and the connecting lines link the points by age. PCA 1 captures experience-dependent changes in total receptor subunit expression, PCA 2 captures changes in the E/I balance and PCA 3 captures the maturation of receptor composition. The developmental trajectory for normal animals (yellow sphere, circle shadows) can be described as a slowly descending curved staircase that traversed a long direction of increasing expression (PCA 1) and slow maturation of receptor subunits (PCA 3) between 2 and 8 weeks of age followed by turning a corner to a new E/I balance (PCA 2) at 12 weeks and pruning back the total receptor expression by 16 weeks. The trajectory for deprived kittens (red cubes, square shadows) was shifted on all three dimensions and truncated from the normal pattern. The difference between normal and deprived kittens was greatest for the (A) central visual field and less for the (B) peripheral and (C) monocular regions.