atypical face pain, trigeminal neuralgia, chronic fatigue syndrome, multiple chemical sensitivity, irritable bowel syndrome, complex regional pain syndrome, migraine headache, speech hearing, swallowing, balance, smell, and taste disorders, and certain cardiovascular diseases. This program announcement seeks research applications that use state-of-the-art, multidisciplinary and interdisciplinary approaches to discover molecular, physiological, and behavioral mechanisms responsible for the overlapping symptoms manifested in the set of disorders that may co-exist with TMJMD. These applications may have as their research focus the chronic, comorbid conditions themselves or TMJMDs, provided that the aims and goals of the project are to discover biological mechanisms linking the comorbidities. While the overarching goal of this announcement is to arrive at a better understanding of potential mechanisms underlying TMJMDs as related to the variety of comorbidities associated with them, it is expected that no single research project will be able to accomplish this. Applicants are, therefore, encouraged to focus their attention on a particular pathway and a specific disease that is comorbid with TMJMD. -Mechanism of Support. This FOA will utilize the Research Project Grant (R01) award mechanism and runs in parallel with FOAs of identical scientific scope, PA-06-267 and PA-06-268, that solicit applications under the Small Research (R03) and the Exploratory/Developmental (R21) grant mechanisms, respectively. -Funds Available and Anticipated Number of Awards. Awards issued under this FOA are contingent upon the availability of funds and the submission of a sufficient number of meritorious applications.