Older individuals have an elevated risk for chronic pain as half of all individuals over 65 years old have at least one chronic pain condition. Unfortunately, relevant assessment tools and recommendations for chronic pain management targeting older adults are lacking. This study explores changes in response to pain between young (2–3 months old) and geriatric (20–24 months old) ages using mice. Although cutaneous thresholds to brisk stimuli (von Frey and radiant heat assays) were not affected, behavioral responses to tonic stimuli (acetone and capsaicin assays) were more pronounced in geriatric animals. After nerve injury, geriatric mice present an altered neuropathic pain profile with hypersensitivity to mechanical stimuli but not acetone and an impairment in conditioned noxious stimuli avoidance. This altered behavioral response pattern was associated with an abnormal monoaminergic signature in the medial prefrontal cortex, suggesting decreased COMT function. We conclude that young and geriatric mice exhibit different behavioral and physiological responses to the experience of pain, suggesting that knowledge and practices must be adjusted for geriatric populations.
|Original language||English (US)|
|Number of pages||11|
|Journal||Neurobiology of Aging|
|State||Published - May 2020|
Bibliographical noteFunding Information:
The authors thank the Alan Edwards Centre for Research on Pain, the staff of the Comparative Medicine and Animal Resources Centre at McGill University for outstanding animal care and husbandry, Ms Lina Naso for technical support, Ms “Sunny” Seonho Jang for technical support and for being a blind observer, Dr. Stéphanie Grégoire for her excellent advice, and Dr. Anne-Julie Chabot-Doré for helpful and inspiring discussions. This work was supported by the Canadian Institutes of Health Research , Canada ( MOP-102586 and MOP-126046 to LSS and MM, and MOP111129 to JZ), and from the Canadian Excellence Research Chairs , Canada(CERC) Program ( CERC09 to LD).
- Geriatric pain
- Healthy aging
- Sensory thresholds
- Supraspinal plasticity
- Tonic and chronic pain response