The goal of this Phase II SBIR project is to develop and validate a laser diode stimulator to assess heat-sensitive Transient Receptor Potential (TRP) ion channels for in vitro and in vivo studies, using patch clamp recording and calcium imaging and compound action potential recording, respectively. This laser will be very useful for new drug discovery and evaluation, as there is currently no commercially available tool of similar capabilities. Evaluation of TRP family proteins can be useful in describing the potential utility of putative analgesic drugs. The ability to selectively (by temperature thresholds), reliably and reproducibly activate TRPs may also provide unique utility in understanding the mechanisms of antagonist action (binding) and provide additional information about mechanisms of interaction of different TRP proteins in cells and nerve tissue. There is also a potential utility of being able to differentially evaluate pain mediated by TRPV1 or TRPV2 proteins in the diagnosis and monitoring of progression of pain patients. Thus, it is our overall goal to establish stimulation protocols for use with a laser stimulator for in vitro and in vivo activation of heat gated ion channels. Laser stimulation is used for selective activation of C and A delta fibers in humans and rats (in our parallel projects), allowing reproducible protocols to test putative analgesic, from cell culture to humans. Thus, we hypothesize that the laser ion channel stimulator will prove safe and reliable action and will meet the FDA requirements for a laser device. To do this, we will develop an additional electronic circuit that allows the blockade of laser emission through the microscope, protecting eyes from any damage. We will also submit the laser and its components for certification of electrical and magnetic interference standards, and make any device changes that are necessary to meet the requirements. In addition, we will develop a protocol of direct temperature measurement of laser-induced temperature and modify the device to allow a tunable rate of heating. We will also insure the compatibility of the laser with calcium imaging and will continue to test the laser with TRPV1 DRG and HEK293 cells in order to study sensitization/desensitization processes. To do this we will apply brief and prolonged laser pulses and capsazepine. We will test the concept of TRP-associated activation of C and A delta fibers by direct laser activation of nerve fibers and application of the TRPV1 and TRPV2 antagonists capsazepine and ruthenium red.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Small Business Innovation Research Grants (SBIR) - Phase II (R44)
Project #
3R44NS046951-02S1
Application #
7555866
Study Section
Special Emphasis Panel (ZRG1-MDCN-L (10))
Program Officer
Stewart, Randall R
Project Start
2003-08-15
Project End
2009-07-31
Budget Start
2007-08-15
Budget End
2008-07-31
Support Year
2
Fiscal Year
2008
Total Cost
$100,000
Indirect Cost
Name
Lasmed, LLC
Department
Type
DUNS #
188720853
City
Mountain View
State
CA
Country
United States
Zip Code
94043
Moeller-Bertram, Tobias; Schilling, Jan M; Ba?konja, Miroslav Misha et al. (2013) Sensory small fiber function differentially assessed with diode laser (DL) quantitative sensory testing (QST) in painful neuropathy (PN). Pain Med 14:417-21
Zhang, Jie; Cavanaugh, Daniel J; Nemenov, Michael I et al. (2013) The modality-specific contribution of peptidergic and non-peptidergic nociceptors is manifest at the level of dorsal horn nociresponsive neurons. J Physiol 591:1097-110
Tzabazis, Alexander Z; Klukinov, Michael; Crottaz-Herbette, Sonia et al. (2011) Selective nociceptor activation in volunteers by infrared diode laser. Mol Pain 7:18
Mitchell, Kendall; Bates, Brian D; Keller, Jason M et al. (2010) Ablation of rat TRPV1-expressing Adelta/C-fibers with resiniferatoxin: analysis of withdrawal behaviors, recovery of function and molecular correlates. Mol Pain 6:94
Cuellar, Jason M; Manering, Neil A; Klukinov, Mikhail et al. (2010) Thermal nociceptive properties of trigeminal afferent neurons in rats. Mol Pain 6:39