Measuring parallel fiber length in the rat cerebellum

A new approach was devised to obtain the mean length of parallel fibers in Golgi sections of the rat cerebellum. This method was based on the principle that within a given region of the cerebellum the mean length of parallel fibers should be inversely proportional to the likelihood of spotting the ends of parallel fibers. An experimental protocol was designed based on the statistical relationship between the mean fiber length and the number of the ends of parallel fibers for a given total length of parallel fibers examined. Our methodology was simple and could have advantages over other existing methods.