A METHOD FOR UTILIZING BIOCYTIN TO STUDY RETINOFUGAL PATHWAYS AT THE LIGHT AND ELECTRON-MICROSCOPIC LEVELS

Numerous methods have been utilized in the past to study the retinofug al pathway at both the light and electron microscopic levels. However, many of these techniques have technical drawbacks that make them diff icult to use in electron microscopic studies. We present herein a meth od for utilizing the anterograde tracer biocytin to study the retinal pathways at both the light and electron microscopic levels. Biocytin i s an especially useful tracer since it clearly labels very small axons and boutons in addition to the larger fibers. In addition, the synapt ic ultrastructure is left intact and the technique can be utilized in numerous double-labeling neuroanatomical studies.