Evidence for the Tapering of Nerve Axons

抄録

Recently, the transverse areas of axons have been used as an index for pathologcal study based on the supposition that the transverse area of the axon is normally maintained constant. It is generally accepted that nerve conduction velocity is directly proportional to the fiber diameter, under the condition mentioned in the proceeding sentence. To verify this supposition, we measured the transverse areas of the facial nerve axons at three positions: proximal, middle and distal in three subjects. We found that the average cross-section area of the axons decreased moderately in proportion to the distance from the soma of each nerve. The diminution ratio averaged about 2.6% per millimeter.