The Area of Cross Sections and the Number of Myelinated Axons of Cranial Nerves III, IV and VI of Adult Horse

Abstract

It was aimed to determine the number of myelinated axons and the area of cross sections of oculomotor, trochlear and abducens nerves providing motor innervation of extrinsic muscles of the eye. The study included 3 male and 3 female adult horses. Tissue samples were taken from the part of nerve being in subarachnoid space. Paraffin blocks of tissues were prepared and cut with a rotary microtome transversely at a thickness of 4 mu m and sections were stained with Masson's trichrome. The area of cross sections was determined with Cavalieri's method and the number of myelinated axons was calculated by fractionator technique. There were no statistically significance of cross sectional areas and the number of myelinated axons of the right and the left sides, thus the data belonging to both sides were accepted as a single data (median). The areas of cross sections of oculomotor, trochlear and abducens nerves were calculated to be 2.647 mm(2), 0.511 mm(2) and 1.092 mm(2) and the number of myelinated axons 13.523, 2.034 and 4.151 respectively. The results of the study performed to determine the area of cross sections and the number of myelinated axons of III., IV. and VI. cranial nerves of the horse will contribute to the knowledge of this area and shed light on the studies to be conducted in the future.