Printed in Great Britain MITOCHONDRIAL EXTENSIONS ASSOCIATED WITH MICROTUBULES IN OUTGROWING PROCESSES FROM CHICK SPINAL CORD IN VITRO

Electron-microscopic examination of processes growing out from chick spinal cord cultivated in vitro raises the possibility that mitochondria may be continuous with a system of membrane-bound profiles ramifying within the cytoplasm. These profiles are distinctive in appearance, and appear to establish a particular spatial relationship with microtubules. In this, dense material extends from the profiles to constitute a meshwork within whose interstices tubules lie. The suggestion is made that these appearances may reflect the utilization of the products of mitochondrial activity for transport by microtubules