Most of the methods used for orofacial pain assessment in rodents have been adapted from limb and tail mechanical and thermal stimulation. However, the results obtained by these methods can be influenced by experimenter interaction, animal attentiveness and potential visual, auditory or whisker sensory cues detected by the rodent when stimulating around the face. Ideally, ethology secondary to pain should be conducted in the home cage environment where there are minimal interventions by the experimenter. Additionally, assessment should be conducted both diurnally and nocturnally to achieve a more accurate representation of pain-related behaviors. The methodology and instrumentation proposed in this set of studies have the potential to identify a novel set of pain behaviors and improves on the deficiencies that have been identified with other techniques. The proposed measures have the potential to identify subtle changes in feeding behavior that are prevalent in orofacial pain conditions such as musculoskeletal pain. This proposal has three specific aims that focus on: (1) identification of behavioral activities associated with the presence or absence of mild to moderate orofacial pain that are reliable and valid;(2) validate the ability of the behavioral assessments to detect analgesic dose-response effects;and (3) using these newly identified behavioral measures, test the efficacy of a non-steroidal anti-inflammatory drug that targets specific ion channels recently reported to be upregulated in the presence of masticatory muscle pain. The overall goal of this proposal is to establish reliable and valid measures of behavioral feeding activities that accurately reflect mild to moderate orofacial pain or pain-free conditions. These behavioral parameters can then be used to evaluate the efficacy of therapeutic interventions that target specific orofacial pain conditions. The automated assessment of orofacial pain behavior in the home cage environment both diurnally and nocturnally would allow a higher throughput of rodent evaluation and quicken the translation of new pain therapeutics for orofacial pain.
Pain that involves the head and face has been difficult to measure in animals. New pain measuring techniques are needed to evaluate facial pain in animals so that new treatments can be developed. This proposal will identify animal feeding behaviors that can be used to measure mild to moderate jaw muscle pain. These behaviors will then be used to test the abilities of drugs to treat jaw muscle pain.