This text is the culmination of 15 years of research on the transplantation of dopaminergic neurons in the striatum of the weaver mouse (wv/wv), a neurological mutant characterized by genetically-determined degeneration of midbrain dopamine neurons. This mutant constitutes the only available laboratory model with a chronic disorder that mimics Parkinson's disease. Structural and functional aspects of intrastriatal mesencephalic neuron grafting into the weaver model are reviewed, including histochemical correlates of graft survival and integration, numerical aspects of donor cell survival, ultrastructural findings on synaptogenesis, neurochemical indices of dopamine uptake and receptor binding, gene expression of structural and neurotransmitter-receptor related molecules, levels of striatal amino acid receptors, and behavioural effects of unilateral and bilateral neuronal transplantations. The book will be useful for researchers and physicians interested in models of Parkinson's disease and in brain repair. It is unique in the sense that it covers in a comprehensive fashion the neuronal transplantation studies that have been conducted in the weaver model, a mutant with neurogenetic dopamine deficiency. The author is a well-known and credible authority on this subject, and has been instrumental in establishing mutant mouse strains as models for neural grafting, and in addressing some important questions on brain tissue restoration and neurological recovery.