Which one of the following does not act as a neurotransmitter ?

Options

A. Acetylcholine
B. Epinephrine
C. Norepinephrine
D. Cortisone

Answer

**Step-by-Step Solution:**

1. **Understand the Definition of Neurotransmitters:**
- Neurotransmitters are chemicals that transmit signals across a synapse from one neuron to another. They play a crucial role in communication within the nervous system.

2. **Identify the Options Given:**
- The options provided are:
- A) Acetylcholine
- B) Epinephrine
- C) Norepinephrine
- D) Cortisone

3. **Evaluate Each Option:**
- **Option A: Acetylcholine**
- Acetylcholine is a well-known neurotransmitter involved in muscle activation and various functions in the central nervous system. Therefore, it cannot be the correct answer.

- **Option B: Epinephrine**
- Epinephrine (also known as adrenaline) acts as a neurotransmitter in the body, particularly in the fight-or-flight response. Thus, it is also not the correct answer.

- **Option C: Norepinephrine**
- Norepinephrine is another neurotransmitter that plays a role in attention and responding actions in the brain. Hence, it is not the correct answer either.

- **Option D: Cortisone**
- Cortisone is a hormone produced by the adrenal glands in response to stress. It is not classified as a neurotransmitter, as it primarily functions in regulating metabolism and immune response rather than transmitting signals between neurons.

4. **Conclusion:**
- Based on the evaluation, the correct answer is **D) Cortisone**, as it does not act as a neurotransmitter.

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