Molecular Mechanisms of Mammalian Thermosensation
Molecular mechanisms of thermosensation and nociception
My lab is interested in understanding how specialized cells in the nervous
system detect changes in ambient temperature. Increases or decreases in
tissue temperature can cause pain, pleasure, or homeostatic changes in
mammals, depending upon their direction, magnitude, and anatomical
location. The molecular basis of this thermosensation, however, is very
poorly understood. Using expression cloning and homology-based
cloning, we recently identified two heat-gated ion channels that are
expressed in distinct subsets of peripheral neurons within the pain
pathway. One of these proteins, VR1, is a channel that can be activated
not only by noxious heat (> 43f C), but also by protons and by capsaicin
(the main pungent ingredient in ‘hot’ peppers). The second channel,
VRL-1, is activated by temperatures exceeding 52f C, but is insensitive to
protons or capsaicin.
Through a multidisciplinary approach involving molecular biology,
biochemistry, calcium imaging, electrophysiology and mouse genetics, we
are focusing on the following goals: 1) Using mouse knockouts of VR1
and VRL-1 to clarify their roles in the pain pathway. 2) Identifying novel
molecules involved in the detection of cold and warm thermal stimuli by
the peripheral and central nervous systems. 3) Dissecting the mechanisms
by which these molecules are activated by increases or decreases in
ambient temperature.
|