Anatomical studies on the optic tract (tractus opticus) of the Indian buffalo (Bubalus bubalis)

The optic tract of the buffalo was found to begin from the posterolateral angle of the chiasma, from where it extended laterally for about 8 mm. Each tract was round in its initial portion, but was flattened subsequently. In its course to the corpus geniculatum laterale (CGL), it swept round the homolateral cerebral peduncle. The tract fibres entered the CGL chiefly on its ventrolateral aspect. The optic fibres appeared to enter the CGL as individual fibres. The fibres in the optic tract were mostly myelinated. There were 253823 +/- 27534-254800 +/- 29232 myelinated fibres in it. There was no fascicular arrangement of these fibres. The calibre of the myelinated fibres in the optic tract varied from 1-12 microns. A fibre diameter analysis revealed an unimodal distribution of these fibres with a peak at 2 microns. Thinner fibres predominated in the peripheral portion of the optic tract. In the central portion, fibres of larger diameter were seen in greater numbers.