HAPLN2 and major depressive disorder: Furthermore, we used immunohistochemistry and western blot-based protein determinations to ascertain whether proteoglycans phosphacan, neurocan, brevican, versican and BRAL1, as well as Tenascin R and associated NR axonal membrane protein neurofascin, are altered in the overall WM neuropil and around individual NRs in the PFC WM in MDD and in rats subjected to CUS.