Biosynthesis • Produced by enzymes in the brain in 2 steps from an amino acid, tyrosine:
First Step • Another hydroxyl group (-OH) is added to ring to form Dopa:
Second Step • Then the carboxyl group (-COOH) is removed to form dopamine.
General Function • Neurotransmitter • Precursor to adrenaline • Linked to feelings of: – Happiness – Excitement – Positivity – Eagerness to pursue goals & rewards
Functions, cont’d • Dopamine levels in the brain are increased by: – Nicotine – Meth • Dopamine is also involved in coordinating muscle movements.
The “Shaking Palsy” • Dr. James Parkinson, London
James Parkinson, M. D. • Son of John Parkinson, an apothecary and surgeon in London. • Later assisted his son, John, in describing appendicitis for the first time. • Very politically active during 1780 s-90 s • World Parkinson’s Day is held on his birthday each year, April 11.
Parkinson’s Disease • Symptom’s begin when the patient has lost approx. 75% of their dopamine-synthesizing cells in the brain. • Dopamine cannot be used as a treatment, b/c it cannot cross the blood-brain barrier. • Most common drug used for treatment: Dopa • Dopa can be transported across the barrier b/c it is an amino acid.