Pain affects the human body not only acutely, but also in the longer term. In particular, intensely occurring pain is stored in pain memory. It alters neurons in the brain and affects genes, which can lead to chronic pain with no apparent cause.
What is pain memory?
Pain affects the human body not only acutely, but also in the longer term. In particular, pain that occurs intensely is stored in pain memory. Complex processes are at the forefront of the emergence of pain memory. Pain stimuli can leave traces in the body if they are not treated. These traces are stored in the spinal cord and the brain. Thus, pain primarily affects the nervous system. Long-lasting pain makes the affected areas more sensitive to stimuli even after healing. This can manifest itself, for example, as hyperalgesia. This is what the medical profession calls an exaggerated sensitivity to pain. On the other hand, pain can also occur with stimuli that would normally have been perceived as harmless or not painful at all. Pain memory is activated primarily when a stimulus has caused pain for too long. Common in severe pain is primary hyperalgesia. For example, after fractures, surrounding areas are more sensitive to pain and tend to hurt at the slightest touch. This pain is basically a protective mechanism of the body. The area must be spared in order to heal reasonably. The development of pain memory can be compared to training effects. Muscles – to put it simply – continue to develop through repeated stimuli. The same happens with synapses that transmit pain stimuli. They become hypersensitive and can become independent over time. In pain memory, a distinction is made between explicit memory and implicit associative memory. In the former, the intensity and nature of former pain are stored rather superficially. The second deals with the sensitization of the periphery and the associated conditioning processes. Imaging techniques can be used to visualize the trace leading to synaptic remodeling.
Function and task
The biological purpose of pain is to detect chemical or mechanical stimuli in time. If possible tissue-damaging stimuli can be detected, the individual strives to prevent the stimulus from occurring in order to relieve or avoid pain. Nerve cells and their extensions are responsible for detecting potential dangers, transmitting the stimuli to the brain, and thus conditioning the prevention of pain. The cells responsible for this are called nociceptors. The task of the pain memory is, among other things, to continue to spare affected areas shortly after the injury. In this way, the healing process is accelerated and the injuries can heal better. The body’s sensitization processes are best studied at the spinal cord. The current results on this come from experiments with mice and rats. Synapses that are responsible for pain transmission change when pain persists. The affected synapse becomes larger and the transmission rate and intensity stronger. This process is also known as long-term potentiation. According to the latest findings, persistent pain also affects the genetics of cells. The body forms new protein chains, which changes the cell membrane. This change leads to faster response to stimuli. This can lead to recurrent or persistent pain.
Diseases and ailments
Pain memory is thus not only responsible for pain becoming chronic, but can also lead to phantom pain. In this case, the pain becomes detached from its original cause. Stimuli are passed on to the brain without a corresponding signal. The consequences are, for example, permanent incorrect postures, as those affected try to relieve the painful area as best they can. These relieving postures are triggered by pain and are originally intended to relieve painful and diseased areas. In this case, however, said relieving postures quickly lead to lack of movement or real pain, since an unnatural posture is always adopted. Depending on the duration, this can also lead to malpositions in the skeletal area. In addition, it can lead to changes in the entire nervous system.Depending on the case, pain may occur in areas far removed from the original trigger. The sensitivity of the entire body to pain increases and the affected person is constantly tense. This tension leads to additional muscle spasms. In some cases, it is almost impossible to see where incorrect strains are coming from. Many patients with chronic pain consult a medical professional who is perplexed as to the cause of the pain. Organic causes often cannot be found in this case. If the patient does not remember the triggering event or does not recognize the connection and inform his doctor, it becomes difficult. However, the pain memory can, with some work, be erased. This is what neurobiology is trying to do. Exercise and relaxation training are used to correct the problems. In addition, psychotherapy is often advised in order to steer trained, incorrect movement patterns back onto the right track. In many cases, the difficulty lies in the fear of the affected persons. Fear of the pain prevents postures that could trigger the stimulus. Therefore, in order to override the pain memory, specialists from different disciplines must work together to achieve the desired results.
