Which of the following statement is true regarding pain perception in neonates? - Answer & Explanation
- Perceive more pain because of increased impulse transmission.
- Perceive less pain because of decreased impulse transmission.
- Perceive more pain because of ill developed descending modulation pathway. ✓ Correct Answer
- Perceive more pain because of ill developed ascending spinothalamic pathway
Explanation:
Ascending (afferent) pain pathways — the spinothalamic tract and nociceptive fibers (Aδ and C fibers) — are functionally present and active by mid-gestation (~24 weeks). This means the neonate’s ability to detect and transmit pain impulses to the brain is already in place.
Descending inhibitory (modulatory) pathways, which normally suppress pain signals, are underdeveloped at birth. These pathways, involving the periaqueductal gray, nucleus raphe magnus, and descending serotonergic/noradrenergic tracts, mature gradually during infancy and early childhood.
Because these descending inhibitory systems are immature, neonates have limited ability to dampen pain signals, resulting in exaggerated or prolonged pain responses.
This explains why even minor procedures (heel prick, venipuncture, intubation) can produce heightened physiological stress (tachycardia, desaturation, increased cortisol levels) in neonates.
Therefore, the correct answer is (C) — neonates perceive more pain due to the immature descending inhibitory modulation system.