A Golgi analysis of the accessory optic fibers terminating in the medial terminal nucleus of the mouse accessory optic system.

Fibers of the accessory optic tract (AOT) terminating in the medial terminal nucleus (MTN) were observed in the mouse by the rapid Golgi method. The AOT fibers, which entered the MTN from its ventromedial aspect, were divided into thick and fine fiber groups, the thick fibers emitting many terminal collaterals of various calibers, and the fine ones generating fine terminal branches. The possibility exists that the retinal neurons sending AOT fibers to the MTN might be heterogeneous in nature.