What term describes a molecule that blocks or inhibits the operation of a neurotransmitter?

What term describes a molecule that blocks or inhibits the operation of a neurotransmitter?

• A. Agonist
• B. Antagonist
• C. Endorphins
• D. Hormones

Answer: (B)

A molecule that blocks or inhibits a neurotransmitter’s action is an antagonist. It binds to receptor sites without activating them, preventing the neurotransmitter from producing its usual signal and reducing the downstream effect at that synapse. This is why it dampens neural communication. In contrast, an agonist would imitate the neurotransmitter and activate the receptor to enhance signaling. Endorphins are natural ligands that can act as agonists at opioid receptors, promoting signaling. Hormones are chemical messengers from glands and are not defined by blocking neurotransmitter action in this context.

A molecule that blocks or inhibits a neurotransmitter’s action is an antagonist. It binds to receptor sites without activating them, preventing the neurotransmitter from producing its usual signal and reducing the downstream effect at that synapse. This is why it dampens neural communication.

In contrast, an agonist would imitate the neurotransmitter and activate the receptor to enhance signaling. Endorphins are natural ligands that can act as agonists at opioid receptors, promoting signaling. Hormones are chemical messengers from glands and are not defined by blocking neurotransmitter action in this context.