Human Molecular Genetics 2013 22:21; pp. 4293–4305; doi: 10.1093/hmg/ddt279

We have discovered some errors in the legend and related method of Fig. 6B in our paper as follows.

In the 3rd line of the Fig. 6B legend (page 4301), the statement "VAPB located at the postsynaptic membrane of C-boutons" is not accurate. The postsynaptic membrane is specifically referring to an area of plasma membrane that is apposed to the presynaptic membrane. The VAPB label was actually associated with the subsurface cistern (SSC) membrane, which is a different entity, but happens to be very close to the postsynaptic membrane. In fact, SSC is one of the definitive features of the C-boutons (hence, how "C"-bouton got its name). Therefore, we would like to change the statement to "VAPB located at the subsurface cistern membrane of C-boutons". This selective targeting of ALS-related mutant VAPB to the C-boutons closely correlates with the alterations of C-bouton morphology and function as observed in the mutant mice.

Additionally, in the 4th line of the Fig. 6B legend (page 4301), we would like to clarify the statement "Three mice more than 10 sections per mouse were examined", in which we ran immune-EM on one mouse each of nTg, WT and P56S VAPB Tg. The correct statement should be "One mouse each of nTg, WT and P56S VAPB Tg was examined".

We also like to make a couple of corrections in the Methods section on "Immunoelectron microscopy" (page 4303). We would like to change the sentence "Spinal cords and cerebella of … (two per group) were" to "Spinal cords of … (one per group) were". We would also like to delete the last line of that same paragraph "Gold particles within 10 fields for each genotype were counted".

Finally, we want to state that these corrections do not affect the outcome and interpretation of this manuscript, but improve the accuracy of the description of the immune-EM work.

The authors apologise for these errors.