Which of the following is NOT a pathway for the neurotransmission of pain?

Which of the following is NOT a pathway for the neurotransmission of pain?

• A. Nuclear peptide linked
• B. Substance P
• C. Glutamate
• D. Bradykinin

Answer: (A)

Pain signaling relies on specific messenger molecules that relay signals from peripheral nociceptors to the central nervous system. Glutamate is the main fast excitatory transmitter used in the spinal cord to convey nociceptive input, while substance P is a neuropeptide that modulates and sustains pain transmission in the dorsal horn. Bradykinin, though it increases pain by activating peripheral nociceptors and promoting sensitization (and can indirectly enhance central signaling), is not a classic neurotransmitter within the central pain pathways. The term described as “Nuclear peptide linked” does not correspond to any established pain-transmitting molecule. Therefore, that option does not represent a pathway for neurotransmission of pain.

Pain signaling relies on specific messenger molecules that relay signals from peripheral nociceptors to the central nervous system. Glutamate is the main fast excitatory transmitter used in the spinal cord to convey nociceptive input, while substance P is a neuropeptide that modulates and sustains pain transmission in the dorsal horn. Bradykinin, though it increases pain by activating peripheral nociceptors and promoting sensitization (and can indirectly enhance central signaling), is not a classic neurotransmitter within the central pain pathways. The term described as “Nuclear peptide linked” does not correspond to any established pain-transmitting molecule. Therefore, that option does not represent a pathway for neurotransmission of pain.