An operant conditioning model to assess changes in feeding behavior associated with temporomandibular joint inflammation in the rat.

Aims: To develop and validate a model in which to assess a loss of function associated with temporomandibular joint (TMJ) inflammation in awake, freely moving rats.

Methods: The dependent variable in the model was the time between food rewards (pellets), or interfeeding interval (IFI). IFI was quantified after rats were trained to "bar-press" for food.

TRPM8 mRNA is expressed in a subset of cold-responsive trigeminal neurons from rat.

Recent electrophysiological studies of cultured dorsal root and trigeminal ganglion neurons have suggested that multiple ionic mechanisms underlie the peripheral detection of cold temperatures. Several candidate "cold receptors," all of them ion channel proteins, have been implicated in this process. One of the most promising candidates is TRPM8, a nonselective cationic channel expressed in a subpopulation of sensory neurons that is activated both by decreases in temperature and the cooling compound menthol.