Nerve endings: rapid appearance of labeled protein shown by electron microscope radioautography.

Electron microscope radioautographs of nerve ending fractions from mouse cerebrum show that radioactive protein is associated with nerve endings 15 and 90 minutes after intracerebral injection of tritiated leucine and lysine. The results are consistent with synthesis of protein at nerve endings, or with extremely rapid transport of particulate protein to nerve endings in the mouse cerebrum, or both.