<http://schema.org/articleBody>
"&amp;lt;p&amp;gt;Treating &amp;lt;a href=&amp;quot;https://www.verywell.com/what-is-chronic-pain-2564641&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;1&amp;quot;&amp;gt;chronic pain&amp;lt;/a&amp;gt;\u00A0isn\u2019t easy, and can be frustrating for both patients and physicians.\u00A0 Pain is difficult to measure reliably, forcing doctors to rely on patients&amp;amp;#39; descriptions, and there\u2019s notoriously little relationship between subjective pain and actual tissue damage.\u00A0 Some people feel almost no pain though their back looks terrible on X-rays, and others suffer from terrible back pain though their X-ray looks fine.\u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Still, helping people with pain has always been a priority for doctors.\u00A0 For this reason, pain in the nervous system has been well-studied. \u00A0We know quite a bit about both how pain signals travel in the body, and how our body normally tries to control those signals.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Pain Signals In the Body&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The body has certain nerves, called &amp;lt;a href=&amp;quot;https://www.verywell.com/what-are-nociceptors-2564616&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;2&amp;quot;&amp;gt;nociceptors&amp;lt;/a&amp;gt;, that send painful signals to the spinal cord.\u00A0 There are different nerves for different types of pain\u2014for example, one type sends information about sharp pain, and another about burning.\u00A0 Pain fibers enter the spinal cord, where they may go up or down a level and synapse with other cells in the posterior horn.\u00A0 From there they cross over to the other side of the cord, and run along the spinothalamic tract to the &amp;lt;a href=&amp;quot;https://www.verywell.com/the-anatomy-of-the-brain-2794895&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;3&amp;quot;&amp;gt;thalamus.&amp;lt;/a&amp;gt;\u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The thalamus then relays painful information to the cerebral cortex.\u00A0 There are multiple cortical areas that correlate with an individual\u2019s subjective report of pain, including the &amp;lt;a href=&amp;quot;https://www.verywell.com/the-neurology-of-motivation-2488716&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;4&amp;quot;&amp;gt;anterior cingulate cortex&amp;lt;/a&amp;gt;, the somatosensory cortex, and the &amp;lt;a href=&amp;quot;https://www.verywell.com/the-science-of-emotions-2488708&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;5&amp;quot;&amp;gt;insula&amp;lt;/a&amp;gt;. \u00A0Because there are multiple cortical areas that deal with pain, cortical damage doesn\u2019t usually neutralize pain unless the lesion is very large.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Natural Pain Control&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;One of the best-known ways to control pain is with pain medications such as &amp;lt;a href=&amp;quot;https://www.verywell.com/what-are-opiates-2795406&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;6&amp;quot;&amp;gt;opiates&amp;lt;/a&amp;gt;.\u00A0 In the 1970s, neuroscientists discovered that our body produces its own opiates, called endogenous opiates.\u00A0 This allows our body a degree of control over the amount of pain we feel.\u00A0 The brain can send signals down the spinal cord to suppress pain signals traveling up the spine.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;A strong example of how the brain controls pain can be demonstrated with\u00A0a &amp;lt;a href=&amp;quot;https://www.verywell.com/what-is-the-placebo-effect-2795466&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;7&amp;quot;&amp;gt;placebo&amp;lt;/a&amp;gt;, an inert substance\u00A0such as a sugar pill that somehow has beneficial medicinal effects.\u00A0 For example, in a study done with people whose wisdom teeth had just been pulled, placebos were able to provide a degree of pain control.\u00A0 If given &amp;lt;a href=&amp;quot;https://www.verywell.com/what-is-suboxone-22060&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;internalLink&amp;quot; data-ordinal=&amp;quot;8&amp;quot;&amp;gt;naloxone&amp;lt;/a&amp;gt;, a drug that blocks both endogenous and exogenous opiates, placebos can lose their effectiveness.\u00A0 Functional MRI studies of people given placebos find changes in the &amp;lt;a href=&amp;quot;http://biology.about.com/od/anatomy/p/Hypothalamus.htm&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;9&amp;quot; rel=&amp;quot;nofollow&amp;quot;&amp;gt;hypothalamus&amp;lt;/a&amp;gt;, periaqueductal grey, and &amp;lt;a href=&amp;quot;http://biology.about.com/od/anatomy/p/medulla-oblongata.htm&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;10&amp;quot; rel=&amp;quot;nofollow&amp;quot;&amp;gt;medulla&amp;lt;/a&amp;gt;, supporting the theory that these structures are involved with endogenous pain control.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Further research has shown that pain in the spinal cord involves two different types of cells, some of which are activated with pain and others that shut off.\u00A0 Opiates turn\u00A0on \u201Coff\u201D cells, and pain stimulates \u201Con\u201D cells.\u00A0 This allows the brain to adjust our experience of pain even at the level of the spinal cord.\u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;How the Brain Controls Pain&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The purpose of pain is to motivate us to escape injury, and to help us to learn to avoid situations likely to injure us in the future.\u00A0 For example, if rats have a painful experience in a room, they\u2019re more likely to avoid that room in the future.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;That may sound simple enough, but often life forces us to make a decision about whether to ignore pain or to take action.\u00A0 For example, if cheese is placed in a room where a rat has had an unpleasant experience, the animal has an internal conflict, and has to make a decision.\u00A0 Understanding that decision helps us to understand chronic pain.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;In 1984, researchers fed\u00A0rats on a hot plate that was turned off.\u00A0 Rats would either get regular rat chow or a chocolate covered graham cracker (which apparently rats enjoy).\u00A0 After two weeks, the hot plate was turned on. \u00A0The rats, of course, jumped off. \u00A0The interesting thing is that the rats who got a chocolate covered graham cracker were slower to leave the hot plate\u2014they would endure more pain in hopes of the reward.\u00A0 Even more interesting was that the rats \u201Cmental toughness\u201D went away entirely with naloxone, suggesting that endogenous opiates were what allowed them to tough it out on the hotplate in expectation of chocolate covered graham cracker goodness.\u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The question remains, what in the brain allows the brain to make this decision of how to respond to pain?\u00A0 What stimulates the brain to activate those endogenous opioids, and what causes the brain to respond to the pain and jump off the plate?\u00A0&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The details are still being worked on, but briefly, when we respond to pain instead of activating the reward system, involve our &amp;lt;a href=&amp;quot;http://biology.about.com/od/anatomy/a/aa042205a.htm&amp;quot; data-component=&amp;quot;link&amp;quot; data-source=&amp;quot;inlineLink&amp;quot; data-type=&amp;quot;externalLink&amp;quot; data-ordinal=&amp;quot;11&amp;quot; rel=&amp;quot;nofollow&amp;quot;&amp;gt;limbic system&amp;lt;/a&amp;gt;\u2014a region known to modulate learning and emotion.\u00A0 This is how we learn to avoid pain in the future.\u00A0 Interestingly, neuroscientists have begun to find changes in these brain areas in people with chronic pain.\u00A0 The hope is that with better understanding, new therapies may treat the pain at its true source, the brain, rather than continuing to hunt unsuccessfully for other causes.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Sources:\u00A0\u00A0&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sub&amp;gt;Amanzio M, Benedetti F. Neuropharmacological dissection of placebo analgesia: expectation-activated opioid systems versus conditioning-activated specific subsystems. The Journal of neuroscience : the official journal of the Society for Neuroscience 1999;19:484-494.&amp;lt;/sub&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sub&amp;gt;Dum J, Herz A. Endorphinergic modulation of neural reward systems indicated by behavioral changes. Pharmacology, biochemistry, and behavior 1984;21:259-266.&amp;lt;/sub&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sub&amp;gt;Hughes J, Smith TW, Kosterlitz HW, Fothergill LA, Morgan BA, Morris HR. Identification of two related pentapeptides from the brain with potent opiate agonist activity. Nature 1975;258:577-580.&amp;lt;/sub&amp;gt;&amp;lt;/p&amp;gt;"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.verywell.com/pain-in-the-nervous-system-2488731>