Electron microscopic radioautography: identification of origin of synaptic terminals in normal nervous tissue.

A method combining intraocular injection of tritiated leucine and electron microscopic radioautography has been used to study the distribution of optic nerve terminals in the monkey lateral geniculate nucleus. Radioactive label is found in only one type of synaptic terminal, which demonstrates that this terminal is of retinal origin and that this approach can be used to study the origin of synaptic terminals in normal tissue.