Background & Aims

Nociceptive threshold and pain responses are changed in elderly as cognitive abilities decline, particularly in patients with Alzheimer’s disease (AD) . While the relationship between pain abnormality and cognitive and memory deficits in aged people is poorly understood.

Methods

To understand the pathological correlation between nociceptive response and cognitive deficits in Alzheimer’s disease patients, the present study compared the nociceptive threshold in response to Von Frey and thermal stimuli, and memory and cognitive performance in novel object recognition and water maze tests in APP/PS1 mouse model of AD.

Results

The results suggested that APP/PS1 mice at 2- month of age did not change the nociceptive threshold to mechanical and thermal stimuli, while 4-month of age APP/PS1 mice reduced the threshold to both mechanical and thermal stimuli. The pain threshold of 8-month-old APP/PS1 mice became lower. However, the cognitive and memory behavior did not change in 2- and 4-month-old of APP/PS1 mice, whereas these AD mice showed impaired cognitive and memory behaviors at 8-month of age as evidenced by decreased discrimination index and number of previous platform crossing and time spent in novel object recognition and Morris water maze tests. The beta amyloid burden was increased in cortex, hippocampus, spinal cord and dorsal horn ganglion as these mice were 8-month of age.

Conclusions

These age-related differences in nociceptive threshold and cognitive behavior may be due to different beta amyloid burden in central and peripheral nervous systems with age in these AD mice.

References

1. Husebo BS, Achterberg W, Flo E (2016) Identifying and Managing Pain in People with Alzheimer’s Disease and Other Types of Dementia: A Systematic Review. CNS Drugs. 30: 481-97.

2. Blanton H, Reddy PH, Benamar K (2023) Chronic pain in Alzheimer’s disease: Endocannabinoid system. Exp Neurol. 360: 114287.

3. Cao S, Fisher DW, Yu T, Dong H (2019) The link between chronic pain and Alzheimer’s disease. J Neuroinflammation. 16(1): 204.

4. Pickering G, Eschalier A, Dubray C (2000) Pain and Alzheimer’s disease. Gerontology. 46(5): 235-41.

5. Merloa, S, Costab L, Chiechioc S, Buscetie CL, Cirannaa L, Santangeloc R, Sortinoa MA, Fornaie F, Nicolettie F, Copanic A (2023) Increased Heat Pain Tolerance but Hyperalgesia to Tonic Inflammatory Pain in the CRND8 Mouse Model of Alzheimer’s Disease. J Alzheimers Dis. 96(1): 77-91.

Presenting Author

Ying Xu

Poster Authors

Ying Xu

MD, PhD

Rutgers, The State University of New Jersey

Lead Author

E-mail

Topics

  • Pain in Special Populations: Elderly