Fig 1: Evidence of myelin breakdown and reduced protein levels of MRF in the fornix in HD. The integrity of myelin rings in the fornix was evaluated on 46 randomly selected electron microscopy (EM) images from four HD and four healthy controls by a rater blinded to the identity of the cases. The number of misshapen myelin rings which contained sheets of swellings, disruptions, folds and irregular shape was significantly increased in HD cases compared to controls (a). Representative EM images from a control (b) and HD case (c). Western blot analysis of WM tissue of the fornix from five HD and four healthy controls revealed no significant differences in axonal markers, neurofilament light chain (d) and heavy chain (e), but a significant increase in MBP-QD9, a marker of demyelination (f) and significant decrease of myelin-regulating factor (MRF, g). The data are expressed as mean ± SD. Mann Whitney test, *p < 0.05. Scale bar in c 1000 nm