Damage to the substantia nigra causes a decrease in the neurotransmitter dopamine. This causes a gradual, generalized increase in muscle tone, which is the main symptom of
A) Parkinson disease.
B) rabies.
C) Alzheimer disease.
D) myasthenia gravis.
E) tetanus.

Question

Quizplus · Accepted Answer

Parkinson disease is characterized by damage to the substantia nigra, leading to a decrease in dopamine levels. This results in a gradual increase in muscle tone known as rigidity, which is a main symptom of the disease. The other conditions listed do not involve damage to the substantia nigra or a decrease in dopamine levels.

Damage to the Substantia Nigra Causes a Decrease in the Neurotransmitter