DOPAMINE, PARKINSONS

Dopamine, a substance used by cells to transmit impulses ( NEURO TRANSMITTERS).
Dopamine is one of 3 major Neurotransmitters known as CATECHOLAMINES, which the body respond to stress and prepare it for the flight-or -fight response. Insufficent dopamine disturbs, The balance between dopamine and other neurotransmitters, such as acetylcholine.
Without dopamine, the nerve cells cannot properly transmit messages, and this results in the loss of muscle function and coordination, Parkinsons either tremor predominant, or postural instability and gait disturbed (pigd Walking Disorders".

( Source ) The National Institute of Neurological Disorders And Stroke (N I D S ).