Gate Control Theory of pain

  • Gate control theory was described by Melzack and Wall in 1965.
  • This theory explains about a pain-modulating system in which a neural gate present in the spinal cord can open and close thereby modulating the perception of pain.
  • The gate control theory suggested that psychological factors play a role in the perception of pain.
  • Pain - an unpleasant sensory and emotional experience associated with actual or potential tissue damage.
  • Analgesia - the selective suppression of pain without effects on consciousness or other sensations.
  • Nociceptors - sensory receptor whose stimulation causes pain
  • Pain threshold: the point at which a stimulus is perceived as painful.
  • Phantom limb pain – feelings of pain in a limb that is no longer there and has no functioning nerves.
  • Sensation – the process of receiving, converting, and transmitting information from the external and internal world to the brain.
Major Concepts 
  • The three systems located in the spinal cord act to influence perception of pain, viz;
    • the substantia gelatinosa in the dorsal horn,
    • the dorsal column fibers, and
    • the central transmission cells.
  • The noxious impulses are influenced by a “gating mechanism.”
  • Stimulation of the large-diameter fibers inhibits the transmission of pain, thus “closing the gate.” Whereas, when smaller fibers are stimulated, the gate is opened.
  • When the gate is closed signals from small diameter pain fibres do not excite the dorsal horn transmission neurons.
  • When the gate is open pain signals excite dorsal horn transmission cells.
  • The gating mechanism is influenced by nerve impulses that descend from the brain.
  • Factors which influence opening and closing the gate are:
    • The amount of activity in the pain fibers.
    • The amount of activity in other peripheral fibers
    • Messages that descend from the brain.
  • A specialized system of large-diameter fibers that activate selective cognitive processes via the modulating properties of the spinal gate.
Gate Control theory
  • Gate is opened by
    • Physical Factors - Bodily injury
    • Emotional Factors - Anxiety & Depression
    • Behavioural Factors - Attending to the injury and concentrating on the pain
  • Gate may be closed by:
    • Physical Pain - Analgesic Remedies
    • Emotional Pain - Being in a ‘good’ mood
    • Behavioural Factors - Concentrating on things other than the injury
  • The theory guided research toward the cognitivebehavioral approaches to pain management.
  • This theory helps to explain how interventions based on somatosensory (auditory, visual and tactile) stimulation such as friction,music therapy and distraction provide pain relief.
  • Melzack (1996) extended the gate control theory explaining phantom limb pain.
  1. Dickenson AH, (2002). Gate Control Theory of pain stands the test of time. Br. J. Anaesth., 88 (6):755-757.
  2. Smeltzer SC, & Bare BG. [Edrs] (2004) . Brunner and Suddarth's Textbook of Medical-Surgical Nursing. 10th edition. Philadelphia: Lippincott Williams & Wilkins.
  3. Melzack, R. (1996). Gate control theory: On the evolution of pain concepts. Pain Forum, 5(1), 128–138.
  4. Melzack R, & Wall PD. ( 1965). Pain mechanisms: a new theory. Science, 150: 971–9 (Free access)


Post a Comment