Arc-Tg mice exhibit juvenile-like OD plasticity well past the conventional critical period. (A) Schematic of recording site for VEPs in layer IV of binocular visual cortex. (B) At P30, both WT and Arc-Tg mice show a significant decrease in contra (closed-eye) VEP amplitude following MD (WT: n = 7, *P = 0.03; Arc-Tg: n = 10, *P = 0.01). Additionally, Arc-Tg mice exhibited a small but significant increase in ipsi (open-eye) VEPs (Arc-Tg: *P = 0.008). There is no significant difference between WT and Arc-Tg animals before or after MD. (C) At P180, only Arc-Tg mice exhibit a significant decrease in contra VEPs (Arc-Tg: n = 6, *P = 0.02). (D) Plot of the fractional change in ipsi (x axis) and contra (y axis) eye VEPs following MD (same data as in B and C). At P30, there is no significant difference between WT and Arc-Tg mice. However, at P180, there is a significant difference between the fractional change of WT and Arc-Tg mice following MD (P = 0.03). Data are represented as mean ± SEM.