The effect of DE on zif268-based activity levels in visual and nonvisual cortices after 7 weeks of ME. A–F, DE in adulthood rejuvenates the ME-induced activity along the different functional subdivisions and cortical layers of the deprived visual cortex. Normalized subdivision-specific ODs for P45 (white), DE (gray), and P120 (black) 7wME mice are shown by dividing the relative zif268 expression of each ME group to its AMC level (7wME/AMC ratio). A direct comparison of ME-induced reactivation levels as a function of age and dark treatment confirmed a limited reactivation pattern, similar to P45, across the upper and lower layers in dark-exposed adult mice. Error bars represent the SEM. G, H, DE also reduced the neuronal activity across all layers of nonvisual areas compared with normally reared adults after 7 weeks of ME. Normalized ODs for P45 (white), DE (gray), and P120 (black) 7wME mice are shown for auditory (G) and somatosensory (H) cortices. In contrast to P120, the auditory cortex of DE 7wME mice (average ± SEM, 36.65 ± 4.62) showed a hypoactive state compared with DE AMC mice (61.66 ± 6.67), which closely resembles P45 7wME. In the somatosensory cortex, DE triggered intermediate activity levels (DE 7wME mice, 60.28 ± 2.61; DE AMC mice, 59.56 ± 4.00) compared with P120 and P45 7wME.