The relation of axonal transport of mitochondria with microtubules and other axoplasmic organelles.

Abstract

Axonal transport of mitochondria was studied in frog [Rana catesbeiana] sciatic nerves incubated in agents selected for their known or alleged effect on microtubules or axonal flow. Quantitative data on mitochondria, microtubules, neurofilaments, endoplasmic reticulum and cross-sectional area of the axon indicated that axonal transport of mitochondria was dependent on microtubules. When more than half of the microtubules were destroyed, the axonal transport of mitochondria was diminished in proportion to the destruction of microtubules. Axonal transport of mitochondria was not related to neurofilaments and endoplasmic reticulum. Changes in the cross-sectional area of axons, even upon reduction to half the normal size, did not noticeably affect mitochondrial transport. CN- which blocks oxidative metabolism also blocked axonal transport of mitochondria, but analysis of fine structure indicated that CN- was destructive to microtubules as well.