Research over the past 15 years has led to a comprehensive description of the processes of axonal sprouting and synaptic reorganization in the hippocampus. Previous studies on axonal sprouting have now been supplemented with recent studies on excitatory amino acid receptor plasticity. These and related studies pave the way to research strategies which detail the molecular mechanisms of the sprouting response. The re-expression of the fetal form of alpha-tubulin mRNA in rat after entorhinal lesions was found to be similar to the re-expression of the human fetal form of alpha-tubulin in Alzheimer's brain. This result suggests that the sprouting process may involve a reactivation of certain developmental mechanisms and that this may possibly contribute to the etiology of Alzheimer's disease.