A NEW METHOD FOR EXPRESSING AXONAL SIZE - RAT OPTIC-NERVE ANALYSIS

Analysis of the shape of the cross sections of adult rat optic nerve a xons reveals that the majority of axons do not have a true circular sh ape. Therefore, determination of axonal size has to utilize methods of approximation. The method presented here utilizes three calculated pa rameters for expression of axonal size: (i) axonal diameter, as calcul ated from its area, or (ii) axonal diameter, as calculated from its pe rimeter, both assuming axonal shape to be a perfect circle and (iii) a xonal shape factor, which represents the divergence of the axon from a perfect circular shape. The use of the calculated axonal diameter, wi th a correction for its shape factor, provides a normalized way of exp ressing axonal size.