Pain Gate and Endorphins
Melzack and Wall's 1965 gate theory and the 1973-75 finds of opioid receptors and the brain's own morphine-like peptides made pain a nerve process that can be tuned.
Open in the interactive tree →In 1965 Ronald Melzack and Patrick Wall proposed that touch fibres can close a 'gate' in the spinal cord on signals from pain fibres, and in 1967 Shealy and colleagues implanted the first spinal cord stimulator for chronic pain on that basis. In 1973 three groups, including Candace Pert and Solomon Snyder, found opioid receptors in brain tissue, and in 1975 John Hughes and Hans Kosterlitz isolated enkephalins, the body's own morphine-like peptides, followed by the sequencing of endorphins in 1976. The gate model is now seen as oversimplified, but it made electrical and drug-based pain relief a research field.
Prerequisites
- Neurotransmitters (Chemical Signals)1921Endorphins are chemical messengers that damp pain signals.
- Action Potential (How Nerves Fire)1952Pain signals travel as nerve impulses along thick and thin fibres.
Unlocks
- Neural Implants & Brain Stimulation1987Spinal cord stimulators for pain were the first implants built on a nerve theory (gate control).