Which chemicals are listed as involved in conveying neural messages?

• A. Serotonin, norepinephrine, epinephrine, dopamine and tryptamine
• B. Acetylcholine, GABA, glutamate, glycine
• C. Insulin, glucagon, cortisol, adrenaline
• D. Sodium, potassium, calcium, chloride

Answer: (A)

Neural messages are carried by neurotransmitters, the chemicals neurons release at synapses to pass signals to the next neuron. The listed set includes serotonin, norepinephrine, epinephrine, dopamine, and tryptamine. These are classic signaling molecules in the brain that modulate mood, arousal, attention, reward, and various neural circuits. Tryptamine is related to the serotonin pathway and can participate in neural signaling as well, so together they illustrate the concept of chemical messengers conveying neural messages.

The other options mix substances that aren’t primarily about direct synaptic signaling. Hormones like insulin, glucagon, and cortisol travel through the bloodstream as endocrine signals rather than across synapses, and ions such as sodium, potassium, calcium, and chloride are essential for generating electrical activity but aren’t themselves the neurotransmitters that convey specific neural messages.