Age-Dependent Ocular Dominance Plasticity in Adult Mice

Abstract

BackgroundShort monocular deprivation (4 days) induces a shift in the ocular dominance of binocular neurons in the juvenile mouse visual cortex but is ineffective in adults. Recently, it has been shown that an ocular dominance shift can still be elicited in young adults (around 90 days of age) by longer periods of deprivation (7 days). Whether the same is true also for fully mature animals is not yet known.Methodology/Principal FindingsWe therefore studied the effects of different periods of monocular deprivation (4, 7, 14 days) on ocular dominance in C57Bl/6 mice of different ages (25 days, 90–100 days, 109–158 days, 208–230 days) using optical imaging of intrinsic signals. In addition, we used a virtual optomotor system to monitor visual acuity of the open eye in the same animals during deprivation. We observed that ocular dominance plasticity after 7 days of monocular deprivation was pronounced in young adult mice (90–100 days) but significantly weaker already in the next age group (109–158 days). In animals older than 208 days, ocular dominance plasticity was absent even after 14 days of monocular deprivation. Visual acuity of the open eye increased in all age groups, but this interocular plasticity also declined with age, although to a much lesser degree than the optically detected ocular dominance shift.Conclusions/SignificanceThese data indicate that there is an age-dependence of both ocular dominance plasticity and the enhancement of vision after monocular deprivation in mice: ocular dominance plasticity in binocular visual cortex is most pronounced in young animals, reduced but present in adolescence and absent in fully mature animals older than 110 days of age. Mice are thus not basically different in ocular dominance plasticity from cats and monkeys which is an absolutely essential prerequisite for their use as valid model systems of human visual disorders.

Environmental enrichment extends ocular dominance plasticity into adulthood and protects from stroke-induced impairments of plasticity

“…To exclude that the observed enhanced plasticity after EE-rearing compared with the SC paradigm was because of a sex and not an environmental difference, we additionally analyzed a group of adult female SC mice. Adult female SC mice (>PD110) also did not show an OD shift to the open eye after MD (SI Results, Data S1: No Sex Difference), which was previously shown for male SC mice of this age range (6). The prolonged sensitive phase for OD plasticity in our EE mice is, therefore, because of the EE rearing and not a sex difference of the experimental animals.…”

“…Interestingly, EE rearing from before birth into adulthood caused very pronounced OD shifts of a size previously only observed in 4-wk-old SC-raised mice: After 7 d MD of the previously stronger, contralateral eye, ODIs became mostly negative, indicating a dominance of the previously weaker, ipsilateral eye. In addition, the OD shift of the adult EE-raised mice was mediated by a reduction in deprived eye responses in V1, which is another hallmark of juvenile OD plasticity (9, 10, 27, 28), whereas OD plasticity in adult SC-raised mice is predominantly mediated by an increase in open-eye responses in V1 (4,9,27) and absent beyond PD110 (6). In contrast to the very strong OD shifts of our EE mice, the OD shifts documented previously in adult and old rats after EE housing (18,20) were not as prominent as in SC rats during the critical period (29)(30)(31)(32).…”

“…O cular dominance (OD) plasticity induced by monocular deprivation (MD) is one of the best studied models of experience-dependent plasticity in the mammalian cortex (1,2). OD plasticity in primary visual cortex (V1) of C57BL/6J mice is maximal at 4 wk of age, declines after 2-3 mo, and is absent beyond postnatal day 110 (PD110) if animals are raised in standard cages (SCs) (3)(4)(5)(6). In 4-wk-old mice, 4 d of MD are sufficient to induce an OD shift to the open eye; therefore, neurons in the binocular V1, which are usually dominated by the contralateral eye in rodents (3,7), become activated more equally by both eyes (5,8).…”

Progressive maturation of silent synapses governs the duration of a critical period

“…Mouse visual cortical responses were recorded through the skull using the imaging method developed by Kalatsky and Stryker and optimized for the assessment of OD plasticity by Cang et al (73,74). The experimenter was blinded for the genotype of the recorded mouse, and data were analyzed as detailed elsewhere (37,73,74). More details are described in SI Materials and Methods.…”

Effects of Monocular Deprivation on the Dendritic Features of Retinal Ganglion Cells

“…Monocular eyelid suture results in anatomical changes in the visual cortex in favor of the non-deprived eye (Wiesel & Hubel, 1965;Tagawa et al, 2005;Cang et al, 2005;Hofer et al, 2006;Lehmann & Löwel, 2008). This phenomenon is referred to as ocular dominance plasticity.…”