Pain Pathways and Nervous System Plasticity: Learning and Memory in Pain
Three pages on PainSci cite McCarberg 2019: 1. The Complete Guide to Low Back Pain 2. Chronic Pain as a Conditioned Behaviour 3. Can pain be conditioned? The plausibility and the evidence
PainSci notes on McCarberg 2019:
A review of the literature on the neurobiology of the relationship between memory and pain, concluding that pain can be modulated substantially by cognitive and emotional inputs, and thus “chronic pain can be seen as persistence of the memory of pain and/or the inability to extinguish painful memories.”
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
OBJECTIVE: This article reviews the structural and functional changes in pain chronification and explores the association between memory and the development of chronic pain.
METHODS: PubMed was searched using the terms "chronic pain," "central sensitization," "learning," "memory," "long-term potentiation," "long-term depression," and "pain memory." Relevant findings were synthesized into a narrative of the processes affecting pain chronification.
RESULTS: Pain pathways represent a complex sensory system with cognitive, emotional, and behavioral influences. Anatomically, the hippocampus, amygdala, and anterior cortex-central to the encoding and consolidation of memory-are also implicated in experiential aspects of pain. Common neurotransmitters and similar mechanisms of neural plasticity (eg, central sensitization, long-term potentiation) suggest a mechanistic overlap between chronic pain and memory. These anatomic and mechanistic correlates indicate that chronic pain and memory intimately interact on several levels. Longitudinal imaging studies suggest that spatiotemporal reorganization of brain activity accompanies the transition to chronic pain, during which the representation of pain gradually shifts from sensory to emotional and limbic structures.
CONCLUSIONS: The chronification of pain can be conceptualized as activity-induced plasticity of the limbic-cortical circuitry resulting in reorganization of the neocortex. The state of the limbic-cortical network determines whether nociceptive signals are transient or chronic by extinguishing pathways or amplifying signals that intensify the emotional component of nociceptive inputs. Thus, chronic pain can be seen as the persistence of the memory of pain and/or the inability to extinguish painful memories. Ideally, pharmacologic, physical, and/or psychological approaches should reverse the reorganization accompanying chronic pain.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
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- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.