α-Synuclein protects neurons from apoptosis downstream of free-radical production through modulation of the MAPK signalling pathway.

α-Synuclein is a pre-synaptic chaperone and its accumulation contributes to differential cell loss in Parkinson's disease. Cytoplasmic expression of α-synuclein can directly modulate apoptotic pathways and contribute to cell survival, whereas induced over-expression of the protein causes oxidative stress through mitochondrial and cytosolic free-radical production. This study aimed to clarify the contribution of endogenous α-synuclein to oxidative stress and its association with cell death.

Axonopathy and cytoskeletal disruption in degenerative diseases of the central nervous system.

There has been growing interest in the axon as the initial focus of pathological change in a number of neurodegenerative diseases of the central nervous system. This review concentrates on three major neurodegenerative conditions--amyotrophic lateral sclerosis, multiple sclerosis and Alzheimer's disease--with emphasis on key cellular changes that may underlie early axonal dysfunction and pathology and, potentially, the degeneration of neurons. In particular, this review will address recent data that indicate that the main pathological stimuli for these conditions, though often not definitively determined, result in an initial perturbation of the axon and its cytoskeleton, which then results in slow neuronal degeneration and loss of connectivity.