The axon terminal uptake and retrograde axonal transport of [3H]leucine and [3H]lysine was investigated. Amino acids were injected into the interpositus nucleus of adult cats, then labeling was studied using light- and electron-microscopic autoradiography. Besides the usual extracellular (terminal) labeling, grains were found in the perikarya of the inferior olive, external cuneate nucleus and the red nucleus. Intra-olivary application of puromycin (known to inhibit protein synthesis) resulted in a significant decrease of the local perikaryonal labeling. In the contralateral inferior olive a diminished incorporation of labeled amino acids into proteins was observed after surgical deafferentation. We conclude that the retrograde axonal transport of amino acids is a useful technique for investigating neuronal pathways and innervation patterns.
ASJC Scopus subject areas