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

Options

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

Answer

To determine which of the following options does not act as a neurotransmitter, we need to first understand what neurotransmitters are and then analyze the given options.

### Step-by-Step Solution:

1. **Define Neurotransmitters**:
- Neurotransmitters are endogenous chemicals that transmit signals from one neuron to another. They play a crucial role in communication within the nervous system.

2. **Analyze the Options**:
- We will look at each option provided to see if it is classified as a neurotransmitter or not.

3. **Option A: Cortisone**:
- Cortisone is a hormone produced by the adrenal gland, primarily in response to stress. It is not involved in transmitting signals between neurons, thus it does not act as a neurotransmitter.

4. **Option B: Acetylcholine**:
- Acetylcholine is a well-known neurotransmitter that plays a key role in muscle activation and various brain functions.

5. **Option C: Affine Efferent**:
- This term appears to be a misrepresentation. However, if we consider "afferent" and "efferent" as types of neurons, they are involved in the transmission of signals. If we consider "affine" as a typo for "affecting," it does not fit the context of neurotransmitters.

6. **Option D: Nor Affine Efferent**:
- Similar to the previous option, if we interpret "nor affine" as referring to norepinephrine (noradrenaline), it is indeed a neurotransmitter involved in the fight-or-flight response.

7. **Conclusion**:
- After analyzing all the options, we conclude that the only one that does not act as a neurotransmitter is **Option A: Cortisone**.

### Final Answer:
**Option A: Cortisone does not act as a neurotransmitter.**

---