Fig 1: Peripheral injury is accompanied by biophysical and biochemical alterations in the hippocampal extracellular matrix. a Experimental timeline: Male C57BL/6 mice underwent tibia fracture and cast immobilization. Seven weeks following injury, brains were decellularized for scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis or left intact for histological and biochemical analyses. b–f Surface scanning electron micrographs demonstrated changes in ECM microarchitecture in the form of altered geometrical micromotifs, and reduced mean fiber diameter as well as a reduction in mean gray values. Scale bar = 400 nm. (Student’s t test, n = 5 mice/group). g, h The examination of ECM stiffness using contact-mode AFM revealed decreased ECM rigidity in the hippocampi of injured mice (Student’s t test, n = 22 measurements each taken from 5 mice/group). i–m Injury is associated with decreased levels of hapln1, aggrecan, and HS2, in addition to decreased levels of MMP8 and increased levels of TIMP2 (Student’s t test, n = 8–12 mice/group). Error bars are s.e.m. *P < 0.05; **P < 0.01; ***P < 0.005