The Neuroscience of Pain: A Journey Through the Mysteries of Our Mind and Body
Introduction
In the first article we looked at some common running injuries and also started to delve into the definitions of injury and whether there needs to be any physical tissue issue for you to experience physical pain. In this article we are going to dive in deeper to get a good understanding of what pain is and how it works.
Because pain is such a complicated topic and often very hard to explain without going into a load of science you probably don’t want to read right now, I’ve put together a short story to help you understand pain a bit better. We can then pull apart individual areas of this story in future articles to tease out a deeper understanding – something I regard as critical if you are going to manage and modulate your own pain.
The Whisper of Pain
It began as a whisper, a fleeting discomfort in Emily’s ankle as she ran along the embankment on a crisp, bright morning. At first, she dismissed it – she had felt her foot slip off a root, but it was a tiny movement; maybe she had banged it as she was loading up the kids’ bags as they rushed into the car for the school run. But over the weeks, the whisper grew louder, becoming a persistent throb that forced her to question: What exactly is pain?
This is Emily’s story, but it could be anyone’s. Pain is universal, yet deeply personal, shaped by biology, psychology, and even society. To understand pain, we must journey into the intricate world of neuroscience, where signals, chemicals, and perceptions weave a complex tapestry.
The Signal of Alarm
Pain begins its journey as a threat signal in the body, often as a response to potential harm. When Emily’s foot slipped off that root, specialised nerve endings called nociceptors sprang into action.
These nociceptors, which reside in her skin, muscles, and organs, are like tiny watchtowers. They detect extreme temperatures, pressure, or chemical changes and send electrical signals racing along her nerves to her spinal cord and brain.
In milliseconds, her body reacted – returning her ankle to its previous position before she was even consciously aware of what had happened. This is the power of the reflex arc, a rapid protective mechanism that bypasses the brain for speed.
The Brain’s Role in Pain
The signals from Emily’s ankle didn’t stop at her spinal cord. They continued their journey to the thalamus, a central relay station in her brain. From there, they were dispatched to various regions:
- The somatosensory cortex, which identified the potential threat’s location and intensity.
- The limbic system, which processed the emotional distress of her rolled ankle.
- The prefrontal cortex, which helped her brain assess the situation and decide what to do next.
Interestingly, Emily’s pain wasn’t just a physical sensation. It was shaped by her thoughts, past experiences, and expectations. This is why neuroscientists say pain lives in the brain.
Chronic Pain – When the Alarm Stays On
Weeks later, Emily’s ankle had long ago healed, but the dull ache persisted. She wondered: Why does it still hurt when there’s no injury?
This is the enigma of chronic pain, where the nervous system continues to send threat signals long after the initial damage has healed. Scientists have discovered that in chronic pain, the nervous system undergoes a process called central sensitisation, making it hypersensitive.
For Emily, this meant that her brain and spinal cord were amplifying normal sensations, interpreting even gentle touches as a threat and creating the experience of them being painful. This phenomenon explains why chronic pain feels so real, even when doctors can’t find a clear cause.
Pain and Emotion – The Brain’s Feedback Loop
Pain and emotion are intricately linked. On stressful days, Emily noticed her pain felt worse. On relaxing weekends, it seemed more bearable.
This is no coincidence. The brain’s pain and emotional centers are deeply intertwined. Neurotransmitters like serotonin and dopamine, which regulate mood, also influence pain perception. Stress can amplify pain by flooding the body with cortisol, a stress hormone that heightens sensitivity.
Emily’s story highlights the importance of addressing not just the physical, but also the emotional aspects of pain.
The Gate Control Theory – A Balancing Act
Emily’s movement coach introduced her to a fascinating concept: the Gate Control Theory of pain.
Imagine a “gate” in the spinal cord that controls whether threat signals reach the brain. By engaging in activities like running and other exercise, massage, sensory stimulation such as skin stretch or vibration, and even laughter, Emily could “close the gate,” reducing her perception of pain.
This explained why certain distractions, like playing her favourite music, seemed to help. Her brain was focusing on other signals, leaving less bandwidth for pain.
Phantom Pain – The Ghost in the System
One day, Emily met Sam, a veteran who’d lost his leg in an accident. Despite the amputation, Sam often felt excruciating pain in his missing limb – a phenomenon called phantom pain.
Sam’s story illuminated the incredible adaptability of the brain, known as neuroplasticity. His brain was still mapping the missing limb, generating threat signals as if it were still there.
Through techniques like mirror therapy, Sam was retraining his brain to quiet these phantom sensations, offering hope for recovery.
Pain’s Silver Lining
Despite its unpleasantness, pain serves a critical purpose. Without it, Emily’s system might not have reacted to control her ankle, potentially leading to severe tissue issues. Conditions like congenital insensitivity to pain, where individuals cannot experience pain, highlight its importance.
However, while acute pain is protective, chronic pain often loses its usefulness, becoming a condition to manage rather than a symptom to treat.
The Future of Pain Management
Emily’s journey led her to explore cutting-edge advancements in pain science. Researchers are developing treatments that target pain at its source, such as:
- Neuromodulation therapies, like spinal cord stimulators, which block threat signals.
- Personalised movement, exercises and drills specifically designed for that individual’s nervous system.
- Personalised sensory stacks, where certain sensory receptors are stimulated in specific ways and stacked together in response to the individual’s nervous system output.
- Personalised medicine, where genetic testing helps tailor treatments.
- Mind-body approaches, like mindfulness meditation, which retrains the brain’s response to threat.
The neuroscience of pain is evolving, offering new hope for millions like Emily and Sam.
Pain as a Teacher
Emily’s experience with pain transformed her perspective. She learned that pain is not just an output signal but a story – a narrative shaped by her body, brain, and environment.
Her journey underscores the resilience of the human spirit and the incredible complexity of the mind. While pain may be inevitable, understanding its science empowers us to rewrite its story.
FAQs
1. Why does pain feel worse during stress?
Stress releases hormones like cortisol, which amplify threat sensitivity by heightening the nervous system’s response.
2. What is central sensitisation in chronic pain?
Central sensitisation is when the nervous system becomes hypersensitive, amplifying normal sensations into threatening ones that result in an experience of pain.
3. How does the Gate Control Theory of pain work?
The Gate Control Theory suggests that “gates” in the spinal cord regulate threat signals to the brain. Distractions or physical activities can close these gates, reducing pain perception.
4. What is phantom pain?
Phantom pain is a sensation of pain in a limb or body part that has been amputated. It occurs because the brain’s map of the body persists even after the loss.
5. Can emotions influence pain?
Yes, emotions and pain are closely connected. Positive emotions can reduce pain perception, while negative emotions can intensify it.
6. What are emerging treatments for chronic pain?
Emerging treatments include neuromodulation therapies, personalised movement strategies, personalised sensory strategies, personalised medicine, and mind-body approaches like mindfulness meditation.
Conclusion
Through Emily’s pain story, you can get a basic understanding of what pain is and how pain works. Effectively, pain is an experience created in the brain in response to threat signals from your body’s tissues, combined with your previous experiences and your beliefs.
In the next article we are going to look at some specific case studies where I have worked with clients to modulate their experience of pain, including avoiding surgery and continuing to be very active and performing at a high level.
In the meantime, here is a great resource from Tame The Beast to help you understand pain a bit better: https://www.tamethebeast.org/
