The root cause of Parkinson's disease is still unknown, but is believed to involve both genetic and environmental factors. The motor-related symptoms of the disease appear to result from the death of cells in the substantia nigra region of the mid-brain. This results in insufficient dopamine in these areas and a programmed cell death. The reason for this cell death is poorly understood, but appears to involve the build-up of proteins into Lewy Bodies in the neurons. However, recent research by Dr Ichiro Kawahata has identified that a novel physiological function of the V-1/CP protein complex, and its potential to augment the gene expression of dopamine markers, may also have an active role. Dopamine is a catecholamine that is used as a neurotransmitter both in the periphery and the central nervous system. Dopamine is a chemical that plays a role in many basic functions of the brain, such as motor co-ordination, reward and memory. It also works as a signalling molecule and acts as a way for brain cells to communicate with one another. Dopamine is released from the specific brain cells that produce it and allow it to bind to target cells, initiating biological process within those cells. Dysfunction in various dopaminergic systems is known to be associated with multiple disorders, including schizophrenia, Parkinson's disease and Tourette's syndrome. The survival of nigral neurons is closely related to the maintenance of nigrostriatal dopaminergic homeostasis. Kawahata and his team approached the problem of Parkinson's causation by examining the characteristics of the dopamine synthetisation and its relationship with tyrosine hydroxylase (TH) identified as the first step in the creation of the hormones that ultimately result in the production of dopamine within the body. The body's production of TH has been found to increase in the presence of dopamine, but the pseudo-phosphorylated tyrosine hydroxylase - the attachment of a phosphoryl group, which is especially important for protein function - itself was found not to increase dopamine levels. There is some evidence that tyrosine hydroxylase-deficiency does not cause Parkinson's disease directly, but probably gives rise to infantile Parkinsonism. This rare disorder is usually identified in infancy and is accompanied by developmental delay, but may not become apparent until later in childhood or even later in life.