“Chronic pain affects a significant percentage of the United States population, and available pain medications like opioids have drawbacks that make long-term use untenable.
Cannabinoids show promise in the management of pain, but long-term treatment of pain with cannabinoids has been challenging to implement in preclinical models. We developed a voluntary, gelatin oral self-administration paradigm that allowed male and female mice to consume ∆9-tetrahydrocannabinol, cannabidiol, or morphine ad libitum.
Mice stably consumed these gelatins over 3 weeks, with detectable serum levels. Using a real-time gelatin measurement system, we observed that mice consumed gelatin throughout the light and dark cycles, with animals consuming less THC-gelatin than the other gelatin groups.
Consumption of all three gelatins reduced measures of allodynia in a chronic, neuropathic sciatic nerve injury model, but tolerance to morphine developed after 1 week while THC or CBD reduced allodynia over three weeks. Hyperalgesia gradually developed after sciatic nerve injury, and by the last day of testing, THC significantly reduced hyperalgesia, with a trend effect of CBD, and no effect of morphine. Mouse vocalizations were recorded throughout the experiment, and mice showed a large increase in ultrasonic, broadband clicks after sciatic nerve injury, which was reversed by THC, CBD, and morphine.
This study demonstrates that mice voluntarily consume both cannabinoids and opioids via gelatin, and that cannabinoids provide long-term relief of chronic pain states. In addition, ultrasonic clicks may objectively represent mouse pain status and could be integrated into future pain models.”
“Peripheral neuropathy can significantly impact the quality of life for those who are affected, as therapies from the current treatment algorithm often fail to deliver adequate symptom relief. There has, however, been an increasing body of evidence for the use of cannabinoids in the treatment of chronic, noncancer pain. The efficacy of a topically delivered 
“Ecological research suggests that increased access to 
“Chronic pain is highly prevalent in most of the industrialized nations around the world. Despite the documented adverse effects, opioids are widely used for pain management. 
“Pain is the most frequent indication for which medical 
“Older adults may benefit from 
“There has been an explosion of interest in the utility of cannabinoids as potential analgesics.
“Growing evidence indicates 
“Understanding how the body regulates pain is fundamental to develop rational strategies to combat the growing prevalence of chronic pain states, opioid dependency, and the increased financial burden to the medical care system.