My research activities focus on the
analysis of neuroplasticity that underlies chronic pain. In one line
of research, we are elucidating those receptors involved in the
processing of nociceptive (painful) input in the periphery. Then,
using models of inflammation coupled with anatomical, behavioral,
pharmacological and electro-physiological techniques, we investigate
how these receptor populations change in acute and chronic
inflammation. We are particularly interested in the role of
ionotropic and metabotropic glutamate receptors as well as
somatostatin and TRPV1 receptors which are expressed by cutaneous
nociceptors. It is becoming clear that a variety of receptors are
present on peripheral axons that influence sensory transduction in
the normal state and contribute to enhanced nociceptor function in
the inflamed state. Investigating neuronal receptor populations in
normal skin and changes in these populations in chronic pain states
may elucidate new avenues for therapy for pain of peripheral origin.
A second focus in the lab is the study
of mechanisms underlying both peripheral and central neuropathic
pain. Using models of peripheral nerve injury or spinal cord
contusion, we are defining those mechanisms contributing to the
aberrant sensory processing that arises following PNS or CNS injury,
respectively. We have demonstrated that a CNS injury (spinal cord
contusion) results in sensitization of primary afferents far from
the injury site. This finding may have implications for other
painful conditions such as fibromyalgia, thalamic post-stroke pain
and migraine pain.
Currently, the lab is funded by two NIH RO1 grants to study neural
mechanisms of peripheral neuropathy and peripheral inflammation.
Fluorescent
staining of lumbar 5 dorsal root ganglion cells: single-labeled SSTR2a
cells appear green (A) and single-labeled TRPV1 cells appear red (B).
When the images are merged, numerous double-labeled cells appear yellow
(C). Arrows identify single-labeled cells, arrowheads identify
double-labeled cells. Bar=25um.
Reprinted from
Carlton et.al., Pain, 2004.
