Pain
-
Decades of efforts in elucidating pain mechanisms, including pharmacological, neuroanatomical, and physiological studies have provided insights into how nociceptive information transmits from the periphery to the brain and the locations receiving nociceptive signals. However, little is known about which specific stimulus-dependent activated neurons, amongst heterogeneous neural environments, discriminatively evoke the cognate pain behavior. We here shed light on the population of neurons in the spinal cord activated by a painful stimulus to identify chronic pain-dependent activated neuronal subsets using Fos2A-iCreER (TRAP2) mice. ⋯ Of interest, spinal neurons expressing calretinin, calbindin, and parvalbumin were activated differently with distinct pain modalities (ie, mechanical allodynia vs heat hyperalgesia). Chemogenetic inhibition of those activated neurons significantly and specifically reduced the response to the pain stimulus associated with the stimulus modality originally given to the animals. These findings support the idea that spinal neuronal ensembles underlying nociceptive transmission undergo dynamic changes to regulate selective pain responses.
-
Randomized Controlled Trial
The effect of vitamin D and omega-3 fatty acid supplementation on pain prevalence and severity in older adults: a large-scale ancillary study of the VITamin D and OmegA-3 triaL (VITAL).
A diet supplemented with vitamin D and marine omega-3 fatty acids may prevent and treat painful disorders by promoting the resolution of inflammation. However, large, randomized placebo-controlled trials evaluating the effects of supplementation with omega-3 fatty acids and vitamin D on the presence and severity of pain are lacking. VITamin D and OmegA-3 triaL-Pain (VITAL-Pain) is an ancillary study to the VITAL trial, a large randomized, double-blind, placebo-controlled trial of vitamin D (2000 IU/day) and omega-3 supplementation (1 g/day) over 5.3 years of median follow-up, among 25,871 older men and women. ⋯ There was no interaction between the 2 active treatments. Dietary supplementation with commonly used moderate doses of vitamin D or omega-3 fatty acids over a median of 5.3 years did not result in a lower prevalence or severity of pain in middle-aged and older U. S. adults.
-
Neural mobilisations (NM) have been advocated for the treatment of nerve-related cervicobrachial pain; however, it is unclear what types of patients with nerve-related cervicobrachial pain (if any) may benefit. Medline, Web of Science, Scopus, PeDro, Cinahl, and Cochrane databases were searched from inception until December 2022. Randomised controlled trials were included if they assessed the effectiveness of NM in nerve-related cervicobrachial pain, and outcome measures were pain intensity and/or disability. ⋯ In most comparisons, there were significant differences in the effectiveness of NM between the subgroups. Neural mobilisations was consistently more effective than all alternative interventions (no treatment, traction, exercise, and standard physiotherapy alone) in 13 studies classified as Wainner cluster. PROSPERO registration: CRD42022376087.