Fig. 2

Setd2 cKO mice largely display altered DTI metrics within the grey matter, but not the white matter, of regions connected by the major forebrain commissures. Representative tractography of Setd2 Ctrl (A–D) and cKO (E–H) brains, highlighting the anterior commissure (AC; A, E), corpus callosum (CC; B, F) and hippocampal commissure (HC; C, G). All three tracts are represented as a merge panel (D, H). Diffusion tensor imaging (DTI) metrics (axial diffusivity (I), apparent diffusion coefficient (J), fractional anisotropy (K) and radial diffusivity (L)) are represented. No differences were noted in any of the major forebrain commissures, except for a significant increase in radial diffusivity within the hippocampal commissure (L). Voxel based morphometry (VBM) analyses of Setd2 Ctrl and cKO are shown in representative average-brain templates for coronal (M–R) and transverse (S–U) planes. VBM revealed decreased (Ctrl > cKO) average fractional anisotropy (blue) within both white matter and grey matter substructures. Decreased FA is represented across the rostrocaudal axis (with M being most rostral, and R being most caudal), as well as along the dorsoventral axis (with S being most dorsal and U being most ventral). No increases in FA were detected using VBM analyses, in agreeance with other findings within this article. Colours for DTI represent the following directionality: green is left–right oriented, red is dorso-ventral oriented, blue is rostro-caudal oriented; oblique fibre orientations are a combination of these colours. nd = no difference; * p < 0.05. For all analyses, n = 10 and n = 9 were used for Ctrl and cKO brains respectively.