The neurotransmitter of preganglionic sympathetic fibre is

Options

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

Answer

To solve the question regarding the neurotransmitter of preganglionic sympathetic fibers, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the neurotransmitter associated with preganglionic sympathetic fibers.

2. **Identify Sympathetic Fibers**: Recognize that sympathetic fibers are part of the autonomic nervous system, which is divided into sympathetic and parasympathetic divisions. Preganglionic fibers are those that originate in the central nervous system and extend to ganglia.

3. **Locate Preganglionic Sympathetic Fibers**: Note that preganglionic sympathetic fibers are primarily found in the thoracolumbar region of the spinal cord (T1 to L2).

4. **Know the Neurotransmitters**: Familiarize yourself with the common neurotransmitters involved in the autonomic nervous system:
- **Acetylcholine (ACh)**: Typically used by preganglionic fibers in both sympathetic and parasympathetic systems.
- **Norepinephrine (NE)**: Generally used by postganglionic sympathetic fibers.
- **Epinephrine and Dopamine**: Not typically associated with preganglionic sympathetic fibers.

5. **Analyze the Options**:
- **Dopamine**: Not the correct answer for preganglionic sympathetic fibers.
- **Epinephrine**: More commonly associated with the adrenal medulla and postganglionic sympathetic fibers.
- **Acetylcholine**: This is the neurotransmitter released by preganglionic sympathetic fibers.
- **Norepinephrine**: Primarily released by postganglionic sympathetic fibers.

6. **Select the Correct Answer**: Based on the analysis, the correct answer is **Acetylcholine**.

### Final Answer:
The neurotransmitter of preganglionic sympathetic fibers is **Acetylcholine**.

---