Figure 1: General model of effective plasticity in wild-type versus Fmr1 KO mice. In primary somatosensory cortex of wild-type mice the capacity for effective plasticity increases rapidly from birth, peaking during the critical period of network development and then normalizing into adulthood. Fmr1 KO mice display a delay in the increased expression of plasticity mechanisms [103] that normalizes at approximately the same developmental time point as wild-type mice [103, 123]. However, persistent deficiencies in plasticity such as dentritic spine dynamics [122] compromise effective plasticity throughout network development in Fmr1 KO mice.