Studies to improve fixation of human nerves. 1. Effect of duration of glutaraldehyde fixation on peripheral nerve morphometry

No change in the transverse fascicular area of rat peroneal nerve occurred when the duration of fixation in 2% glutaraldehyde was increased from 1 to 12 hr. Shrinkage in endoneurial area was inferred from the development of clefts. The number of myelin lamellae remained constant when the nerve was fixed in glutaraldehyde for 1 or for 12 hr. Unequivocal shrinkage of axis cylinders occurred with prolongation of glutaraldehyde fixation beyond 1 hr. In nerves fixed for 12 hr, this shrinkage was approximately 20%, compared to the area at 1 hr.