Question

Which of the following neurotransmitters is associated with both schizophrenia and Parkinson's disease? (A) GABA (B) Serotonin (C) Dopamine (D) Enkephalins

Short answer

Dopamine (C)

Step-by-step solution

Identify Diseases

Understand that the question involves both schizophrenia and Parkinson's disease. Recognize that you need to find a common neurotransmitter linked to both.

Review Schizophrenia

Recall that schizophrenia is associated with an imbalance of the neurotransmitter Dopamine. Elevated levels of Dopamine are observed in individuals with schizophrenia.

Review Parkinson's Disease

Remember that Parkinson's disease is characterized by a decrease in Dopamine levels. The loss of Dopamine-producing neurons is a hallmark of this disease.

Compare Neurotransmitters

Look at the options provided: GABA, Serotonin, Dopamine, and Enkephalins. Identify which neurotransmitter is linked to both the increase and decrease scenarios mentioned.

Select Dopamine

Dopamine is the neurotransmitter that is associated with high levels in schizophrenia and low levels in Parkinson's disease. Therefore, Dopamine is the correct answer.

Key concepts

Dopamine and Schizophrenia

Dopamine plays a critical role in the brain's reward system and in regulating mood. In schizophrenia, there is an imbalance of dopamine levels. Specifically, there is an overactivity of dopamine transmission in certain brain regions.
This heightened dopamine activity is linked to the positive symptoms of schizophrenia, such as hallucinations and delusions.
Understanding this connection helps in designing medications that target dopamine receptors to alleviate these symptoms.
However, not all symptoms of schizophrenia are related to dopamine. Negative symptoms, like reduced emotional expression, may involve other neurotransmitters.

Dopamine and Parkinson's Disease

Parkinson's disease fundamentally involves the depletion of dopamine-producing neurons in the brain, particularly in a region called the substantia nigra. This depletion results in a significant decrease in dopamine levels.
Dopamine is essential for regulating movement. Therefore, its deficiency leads to the characteristic motor symptoms of Parkinson's disease, such as tremors, bradykinesia (slowness of movement), and muscle rigidity.
Treatment often includes medications that increase dopamine levels in the brain or mimic its action, aiming to improve these motor symptoms.

Neurotransmitter Imbalance

A neurotransmitter imbalance can greatly affect mental and physical health. Neurotransmitters are chemical messengers that transmit signals across synapses in the brain.
When these chemicals are not in their proper levels, it can lead to disorders. For example, an excess of dopamine is linked with schizophrenia, while a deficit is linked with Parkinson's disease.
Other neurotransmitter imbalances also play crucial roles in different conditions:

• Serotonin imbalance is often associated with depression and anxiety.
• GABA (gamma-aminobutyric acid) imbalance is related to conditions like epilepsy and generalized anxiety disorder.
• Acetylcholine imbalance is involved in Alzheimer's disease.

Maintaining balanced neurotransmitter levels is crucial for optimal brain function and overall health.