In a study, researchers measured the levels of dopamine in the substantia nigra of postmortem brains from patients diagnosed with Parkinson's disease and compared them to age-matched controls. Patients showed approximately 70-80% loss of dopamine-producing neurons. Researchers also gave living patients L-dopa, a precursor to dopamine, and observed reductions in tremor and rigidity in many patients within hours of administration.
L-dopa is best classified as which type of drug?
- A
An antagonist that blocks dopamine receptors
- B
A reuptake inhibitor for serotonin
- Ccheck_circle
An agonist that increases dopamine availability
- D
A GABA antagonist
Explanation
Agonists are drugs that mimic or increase the effect of a neurotransmitter. L-dopa is converted to dopamine, increasing its availability and acting as an indirect agonist. Antagonists block neurotransmitter activity.