An autoradiographic study of uptake of exogenous glycine by vertebrate spinal cord splices in vitro.

Abstract

Spinal cord slices from rat and goldfish were incubated with3H-glycine and3H-leucine. After fixation, the slices were examined by both light and electron microscopic autoradiography. Light microscopic autoradiograms showed, in slices incubated with3H-glycine, a high level of uptake at discretely localized sites in the ventral horn grey matter with particular concentrations around the perikarya of motor neurons. Electron microscopic autoradiograms revealed that glycine had been taken up by axon terminals containing ‘flat’ synaptic vesicles. There was no uptake into terminals containing ‘round’ vesicles. The spinal cord slices incubated with3H-leucine showed very low levels of radioactivity randomly scattered throughout the tissue.