Anesthesiology; Nervous System; Neurochemistry; Neurons; Neurophysiology; Pain; Electrophysiological Processes; Nociceptive Pain
Our research focuses on the neural mechanisms of pain and itch. Experiments on pain examine the functional properties of dorsal root ganglion (DRG) neurons in the rodent. We are currently interested in how electrophysiological and neurochemical changes in these properties, occurring after a chronic compression of the DRG (CCD model), lead to behavioral signs of neuropathic pain. This type of pain might be produced in humans after injuries and degenerative disorders of the spine. Our experiments on itch use psychophysical methods in humans and behavioral testing in animals to measure itch and nociceptive sensations that can occur under normal conditions and after inflammatory or neuropathic disorders affecting the skin.
In our animal models, the neural encoding of normal and pathological itch vs. pain is measured using imaging and electrophysiological recordings of visualized sensory neurons in vitro and in vivo. Transgenic mice are used that express a fluorescent marker in a subset of itch or pain mediating DRG neuron to facilitate identification for functional studies. A major goal is to identify neurons and neurochemical mechanisms that could be targeted in clinical treatments of chronic pruritus or pain.
Specialized Terms: Pain; Dorsal root ganglion; Neurons; Electrophysiological; Neurochemical; Itch; Psychophysical; pruritic; Nociceptive sensations; Anesthesiology; Electrophysiology; Nervous System; Neurophysiology; Sensory System
Psychophysical Measurements of Itch and Nociceptive Sensations in an Experimental Model of Allergic Contact Dermatitis.
Pall PS, Hurwitz OE, King BA, LaMotte RH. Psychophysical Measurements of Itch and Nociceptive Sensations in an Experimental Model of Allergic Contact Dermatitis. 2015. J Pain 16(8):741-749
CXCR3 chemokine receptor signaling mediates itch in experimental allergic contact dermatitis.
Qu L, Fu K, Yang J, Shimada SG, LaMotte RH. CXCR3 chemokine receptor signaling mediates itch in experimental allergic contact dermatitis. 2015. Pain 156(9):1737-1746
Enhanced excitability of MrgprA3-positive and MrgprD-positive nociceptors in a model of inflammatory itch and pain
Qu L, Fan N, Ma C, Wang T, Han L, Fu K, Wang Y, Shimada SG, Dong X, LaMotte RH. Brain 137(Pt 4):1039-1050
A subpopulation of nociceptors specifically linked to itch.
Han, L., Ma, C., Liu, Q., Weng, H.J., Cui, Y., Tang, Z., Kim, Y., Nie, H., Qu, L., Patel, K.N., Li, Z., McNeil, B., He, S., Guan, Y., Xiao, B., LaMotte, R.H. & Dong, X. (2012). A subpopulation of nociceptors specifically linked to itch. Nature Neuroscience 16(2), 174-182. PMCID: PMC3557753
In-vivo responses of cutaneous C-mechanosensitive neurons in mouse to punctate chemical stimuli that elicit itch and nociceptive sensations in humans.
Ma C, Nie H, Gu Q, Sikand P, LaMotte RH. In-vivo responses of cutaneous C-mechanosensitive neurons in mouse to punctate chemical stimuli that elicit itch and nociceptive sensations in humans. J. Neurophysiol 107(1):357-63, 2012.
Behavioral differentiation between itch and pain in mouse
Shimada SG and LaMotte RH (2008) Behavioral differentiation between itch and pain in mouse, Pain, 139, 681, Published
Full List of PubMed Publications
- LaMotte RH: Allergic Contact Dermatitis: A Model of Inflammatory Itch and Pain in Human and Mouse. Adv Exp Med Biol. 2016. PMID: 26900060
- Song XJ, LaMotte RH, Xie Z: Regulation of Cytokines in Cancer Pain. Mediators Inflamm. 2016; 2016 Mar 20. PMID: 27087747
- Wang T, Hurwitz O, Shimada SG, Qu L, Fu K, Zhang P, Ma C, LaMotte RH: Chronic Compression of the Dorsal Root Ganglion Enhances Mechanically Evoked Pain Behavior and the Activity of Cutaneous Nociceptors in Mice. PLoS One. 2015 Sep 10; 2015 Sep 10. PMID: 26356638
- Qu L, Fu K, Yang J, Shimada SG, LaMotte RH: CXCR3 chemokine receptor signaling mediates itch in experimental allergic contact dermatitis. Pain. 2015 Sep. PMID: 25932692
- Pall PS, Hurwitz OE, King BA, LaMotte RH: Psychophysical measurements of itch and nociceptive sensations in an experimental model of allergic contact dermatitis. J Pain. 2015 Aug; 2015 May 19. PMID: 26002605
- Fu K, Qu L, Shimada SG, Nie H, LaMotte RH: Enhanced scratching elicited by a pruritogen and an algogen in a mouse model of contact hypersensitivity. Neurosci Lett. 2014 Sep 5; 2014 Apr 3. PMID: 24704378
- Qu L, Fan N, Ma C, Wang T, Han L, Fu K, Wang Y, Shimada SG, Dong X, LaMotte RH: Enhanced excitability of MRGPRA3- and MRGPRD-positive nociceptors in a model of inflammatory itch and pain. Brain. 2014 Apr; 2014 Feb 18. PMID: 24549959
- LaMotte RH, Dong X, Ringkamp M: Sensory neurons and circuits mediating itch. Nat Rev Neurosci. 2014 Jan. PMID: 24356071
- Pan X, Durrett RE, Zhu H, Tanaka Y, Li Y, Zi X, Marjani SL, Euskirchen G, Ma C, Lamotte RH, Park IH, Snyder MP, Mason CE, Weissman SM: Two methods for full-length RNA sequencing for low quantities of cells and single cells. Proc Natl Acad Sci U S A. 2013 Jan 8; 2012 Dec 24. PMID: 23267071
- Qu L, Li Y, Pan X, Zhang P, LaMotte RH, Ma C: Transient receptor potential canonical 3 (TRPC3) is required for IgG immune complex-induced excitation of the rat dorsal root ganglion neurons. J Neurosci. 2012 Jul 11. PMID: 22787041
- Fan N, Donnelly DF, LaMotte RH: Chronic compression of mouse dorsal root ganglion alters voltage-gated sodium and potassium currents in medium-sized dorsal root ganglion neurons. J Neurophysiol. 2011 Dec; 2011 Sep 14. PMID: 21917996
- Sikand P, Shimada SG, Green BG, LaMotte RH: Sensory responses to injection and punctate application of capsaicin and histamine to the skin. Pain. 2011 Nov; 2011 Jul 29. PMID: 21802851
- Qu L, Zhang P, LaMotte RH, Ma C: Neuronal Fc-gamma receptor I mediated excitatory effects of IgG immune complex on rat dorsal root ganglion neurons. Brain Behav Immun. 2011 Oct; 2011 Apr 18. PMID: 21521651
- LaMotte RH, Shimada SG, Sikand P: Mouse models of acute, chemical itch and pain in humans. Exp Dermatol. 2011 Oct. PMID: 21929688
- Fan N, Sikand P, Donnelly DF, Ma C, Lamotte RH: Increased Na+ and K+ currents in small mouse dorsal root ganglion neurons after ganglion compression. J Neurophysiol. 2011 Jul; 2011 Apr 27. PMID: 21525373
- Sikand P, Dong X, LaMotte RH: BAM8-22 peptide produces itch and nociceptive sensations in humans independent of histamine release. J Neurosci. 2011 May 18. PMID: 21593341
- Ma C, Rosenzweig J, Zhang P, Johns DC, LaMotte RH: Expression of inwardly rectifying potassium channels by an inducible adenoviral vector reduced the neuronal hyperexcitability and hyperalgesia produced by chronic compression of the spinal ganglion. Mol Pain. 2010 Oct 6; 2010 Oct 6. PMID: 20923570
- Ma C, Donnelly DF, LaMotte RH: In vivo visualization and functional characterization of primary somatic neurons. J Neurosci Methods. 2010 Aug 15; 2010 Jun 14. PMID: 20558205
- Zhang H, Mei X, Zhang P, Ma C, White FA, Donnelly DF, Lamotte RH: Altered functional properties of satellite glial cells in compressed spinal ganglia. Glia. 2009 Nov 15. PMID: 19330845
- Sikand P, Shimada SG, Green BG, LaMotte RH: Similar itch and nociceptive sensations evoked by punctate cutaneous application of capsaicin, histamine and cowhage. Pain. 2009 Jul; 2009 May 6. PMID: 19423224
- Friedman RM, Hester KD, Green BG, LaMotte RH: Magnitude estimation of softness. Exp Brain Res. 2008 Nov; 2008 Aug 5. PMID: 18679665
- Shimada SG, LaMotte RH: Behavioral differentiation between itch and pain in mouse. Pain. 2008 Oct 31; 2008 Sep 11. PMID: 18789837
- LaMotte RH, Ma C: Hyperexcitable neurons and altered non-neuronal cells in the compressed spinal ganglion. Sheng Li Xue Bao. 2008 Oct 25. PMID: 18958366
- Ma C, LaMotte RH: Multiple sites for generation of ectopic spontaneous activity in neurons of the chronically compressed dorsal root ganglion. J Neurosci. 2007 Dec 19. PMID: 18094245
- Ma C, LaMotte RH: Enhanced excitability of dissociated primary sensory neurons after chronic compression of the dorsal root ganglion in the rat. Pain. 2005 Jan. PMID: 15621370
- Yao H, Donnelly DF, Ma C, LaMotte RH: Upregulation of the hyperpolarization-activated cation current after chronic compression of the dorsal root ganglion. J Neurosci. 2003 Mar 15. PMID: 12657665
- Ma C, Shu Y, Zheng Z, Chen Y, Yao H, Greenquist KW, White FA, LaMotte RH: Similar electrophysiological changes in axotomized and neighboring intact dorsal root ganglion neurons. J Neurophysiol. 2003 Mar; 2002 Nov 20. PMID: 12612024
- Friedman RM, Khalsa PS, Greenquist KW, LaMotte RH: Neural coding of the location and direction of a moving object by a spatially distributed population of mechanoreceptors. J Neurosci. 2002 Nov 1. PMID: 12417680