Chapter 27 Increased expression of the major embryonic αaL-tubulin mRNA, TαaL1, during neuronal regeneration, sprouting, and in Alzheimer's disease

This chapter summarizes studies examining expression of Tαl and T26 α-tubulin mRNAs in developing and mature neurons of the rat. These studies demonstrate that abundant expression of Tαl mRNA is specifically associated with process outgrowth in developing and regenerating central neurons, whereas expression of T26 mRNA is constitutive in all neural cell types. Tαl α-tubulin mRNA is also up-regulated after lesions of the entorhinal cortex in both injured and uninjured neurons, and during contralateral sprouting of sympathetic neurons of the superior cervical ganglion. It has been observed that bαl α-tubulin mRNA, the human homologue of Tαl, is expressed at elevated levels in the hippocampus of patients with Alzheimer's disease (AD). Thus, expression of Tαl α-tubulin mRNA is associated with the growth or remodeling of both developing and mature neurons. Induction and aberrant regulation of this growth-associated mRNA may contribute to some of the cytoskeletal abnormalities observed in neuropathological disorders such as Alzheimer's disease.