Microtubules, a complex network of protein filaments found in the cytoplasm of the cell, are important in the maintenance of form and function in nerve cells. Developing nerve cells require the capacity to stabilize certain microtubule populations, as well as the ability to make new microtubules. Abnormalities observed in the aging brain may result from abnormal modulation of microtubule stability. Understanding the regulation of neuronal form and function will depend on knowing the mechanisms that regulate microtubule assembly and stability. Microtubules, comprised of the protein tubulin that has been acetylated, have been shown to be more stable. The investigator will study whether tubulin acetylation regulates microtubule stability in neurons by purifying an enzyme from brain tissue that acetylates tubulin. The enzyme preparation will be used to acetylate brain microtubules in vitro, to determine whether the microtubules cold stability is altered due to the effects of the binding of microtubule-associated proteins. These studies will provide information on acetylated tubulin enzyme regulation during postnatal brain development, maturation and aging.