1 / 13

The Puzzle of Pain

The Puzzle of Pain. The Reverend Dr. David CM Taylor http://pcwww.liv.ac.uk/~dcmt/painpuz.ppt. “The Puzzle of Pain”. “Tell me where it hurts…”. There is more than one. Gate Control Theory. Melzack and Wall in 1968 rubbing injured region decreases pain sensation detail wrong but useful.

carlo
Download Presentation

The Puzzle of Pain

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Puzzle of Pain The Reverend Dr. David CM Taylor http://pcwww.liv.ac.uk/~dcmt/painpuz.ppt

  2. “The Puzzle of Pain”

  3. “Tell me where it hurts…”

  4. There is more than one ....

  5. Gate Control Theory • Melzack and Wall in 1968 • rubbing injured region decreases pain sensation • detail wrong but useful

  6. Descending Inhibition • Touch • cortico-thalamic pathways • why we don’t feel clothes • Pain • battle and sporting injuries, ecstasy • children, animals, elderly/suffering

  7. Descending control of pain • microinjection of opiates into discrete regions of the CNS (PAG,limbic system, SG) produces analgesia • Microstimulation there also produces analgesia • Opioid peptides are present there • Electrical stimulation of the PAG or NRM produces analgesia

  8. Just for re-orientation

  9. Proposed mechanism limbic system periaqueductal grey nucleus raphe magnus interneurones in lamina II of spinal cord

  10. Scratch pad if needed

  11. from brain to brain Presynaptic hypothesis 5HT enkephalin substance P fibre pioneered by Leslie Iversen

  12. How might control work? • Electrical (“Sherringtonian or…”) • Shorter action potentials, • Altered levels of “second messengers” • less Ca2+, less transmitter release, less activity • Chemical • Alter gene expression • Change level or type of • transmitter released or • Receptors on post synaptic cells

  13. Post-synaptic hypothesis from brain A fibre touch to brain c-fibre “pain” This is the currently accepted “gate control” theory

More Related