At the most basic level, opioids bind to specific sites, called µ-opiate receptors (MOR), which suppresses the stimulation of pain. Characteristically, opioids are only known to alleviate pain while bound to these sites, therefore once treatment is ceased, pain resumes.
Typically, for chronic pain, opioids are administered continuously in moderate doses in order to achieve a permanent binding. This method may result in pain relief, however the treatment is long-term and the cause of pain cannot be eliminated.
To test their theory, that memory traces of pain can be erased with a large enough dose of opioids over a short period, “scientists recreated a surgical procedure in vivo in which pain fibres were stimulated under controlled conditions”.
"Although deep anaesthesia prevents any sensations of pain, we were able to reserve long-term synaptic potentiation in the spinal cord. Despite anaesthesia, there appears to be a memory trace for pain and a pain amplifier has engaged."
“Long-term potentiation (LTP) is a long-lasting enhancement in signal transmission between two neurons that results from stimulating them synchronously.”
Researchers administered high doses of intravenous opioids over a period of an hour and discovered that this completely removed the long-term potentiation. By doing so, this can reverse the cellular changes that cause pain memories. As such, this could actually rid the memory of the sensation that pain is amplified and longer lasting than in actuality and avoid the development chronic pain syndrome.
If proven to be an effective method of treatment, this could mean more than pain management for many people suffering with chronic pain. Current methods temporarily relieve symptoms of pain and typically require long-term opioid use. This type of treatment could greatly reduce the risk of a rapidly growing form of addiction.
Opioids Erase Memory Traces of Pain
mu Opioid receptor