Question

Which class of neurotransmitters would be most affected by a toxin that disrupts microtubules within neurons?

• A. Amino acid transmitters
• B. Catecholamine transmitters
• C. Membrane-soluble transmitters
• D. Peptide transmitters

Hint:

Peptides are made in the "City" (Soma) and need the "Train" (Microtubules) to reach the "Dock" (Terminal).

Answer 1

The Correct Option is D

Step 1: Concept
Microtubules are essential components of the axonal transport system, acting as "tracks" for moving vesicles from the cell body to the synaptic terminals.

Step 2: Meaning
Different neurotransmitters are synthesized in different locations. Small molecules like catecholamines and amino acids are often synthesized directly at the axon terminal.

Step 3: Analysis
Peptide neurotransmitters (neuropeptides) must be synthesized in the cell body (soma) because they require ribosomes and the Golgi apparatus. They are then packaged into large dense-core vesicles and transported down the axon via microtubule-based motors (kinesin).

Step 4: Conclusion
If microtubules are disrupted, the transport of peptide transmitters from the soma to the terminal is halted, making them the most affected class. Final Answer: (D)