Figure 2.

Emerging biological themes in ASD. (a,b) Predominant areas of neuroanatomical convergence in ASD. (a) Aberrant brain growth trajectories, with the size of ASD brains outlined in red against a background of normal brains [144-146] (images adapted from [157]); (b) abnormal cortical columns [151]. (c,d) Systems-level convergence in ASD. (c) White matter tract and functional connectivity abnormalities [126,147-150,152,153] (images reproduced with permission from Mark Bastin, University of Edinburgh, UK); (d) excitation/inhibition network imbalances [93,132,136-141], (e-g) Genetic convergence at the cellular and molecular levels. ASD-associated genes implicated in (e) activity-dependent protein synthesis [17,21,23,79,109,113-123], (f) neuronal activity [21,22,25,70,105-112], and (g) neuronal cell adhesion [20-22,34-37,49-52,68,75,79,93,109,126-129,131-137].