Education and Training

Research Interests

I have a long-standing research interest in chronic pain and developing therapeutic tools to manage this debilitating condition. My current research focuses on mechanisms of pain chronification, namely transition from acute to chronic pain, without underlying persistent tissue injury. This type of chronic pain is recently termed ‘nociplastic pain’, implying persistent plastic changes in the nociceptive neural circuit itself in this chronic pain state. There is growing appreciation that changes in synaptic strength (i.e., synaptic plasticity) are associated with chronic pain, and primary afferent input dynamically contributes to synaptic plasticity in spinal nociceptive circuit. Using behavioral, molecular biological, electrophysiological, and Ca2+-imaging approaches combined with optogenetic and chemogenetic tools, my lab investigates such long-term changes in peripheral and central nociceptive circuit components including non-neuronal cells (e.g., spinal glia). 
I have also studied chronic visceral pain associated with inflammatory diseases as well as functional bowel disorders. Visceral organs are innervated by at least two different sensory pathways (e.g., vagal and splanchnic nerve pathways for upper visceral organs, and lumbar splanchnic and pelvic nerve pathways for lower pelvic organs), and my work has contributed to understanding of the characteristics of these different sensory pathways by, for example, examining their ion channel expression and electrophysiological properties. In addition, my research goal to identify potential therapeutic targets led me to development and characterization of animal models of visceral pain, and discoveries of important roles of two-pore domain K+ (K2P) channels in primary afferent neurons and condition-specific involvement of colonic inflammatory molecules in visceral hypersensitivity.

Selected Publications

Wang J, La JH, Hamill OP. PIEZO1 Is Selectively Expressed in Small Diameter Mouse DRG Neurons Distinct From Neurons Strongly Expressing TRPV1. Front Mol Neurosci. 2019 Jul 19;12:178. doi: 10.3389/fnmol.2019.00178. PMID: 31379500

Shim HS, Bae C, Wang J, Lee KH, Hankerd KM, Kim HK, Chung JM, La JH. Peripheral and central oxidative stress in chemotherapy-induced neuropathic pain. Mol Pain. 2019 Jan-Dec;15:1744806919840098. doi: 10.1177/1744806919840098. PMID: 30857460

Bae C, Wang J, Shim HS, Tang SJ, Chung JM, La JH. Mitochondrial superoxide increases excitatory synaptic strength in spinal dorsal horn neurons of neuropathic mice. Mol Pain. 2018 Jan-Dec;14:1744806918797032. doi: 10.1177/1744806918797032. PMID: 30152257

La JH, Chung JM. Peripheral afferents and spinal inhibitory system in dynamic and static mechanical allodynia. Pain. 2017 Dec;158(12):2285-2289. doi: 10.1097/j.pain.0000000000001055. PMID: 28885453

Bittar A, Jun J, La JH, Wang J, Leem JW, Chung JM. Reactive oxygen species affect spinal cell type-specific synaptic plasticity in a model of neuropathic pain. Pain. 2017 Nov;158(11):2137-2146. doi: 10.1097/j.pain.0000000000001014. PMID: 28708760

La JH, Wang J, Bittar A, Shim HS, Bae C, Chung JM. Differential involvement of reactive oxygen species in a mouse model of capsaicin-induced secondary mechanical hyperalgesia and allodynia. Mol Pain. 2017 Jan-Dec;13:1744806917713907. doi: 10.1177/1744806917713907. PMID: 28587509

Schwartz ES, La JH, Young EE, Feng B, Joyce S, Gebhart GF. Chronic Prostatitis Induces Bladder Hypersensitivity and Sensitizes Bladder Afferents in the Mouse. J Urol. 2016 Sep;196(3):892-901. doi: 10.1016/j.juro.2016.03.077. PMID: 26997315

La JH, Feng B, Kaji K, Schwartz ES, Gebhart GF. Roles of isolectin B4-binding afferents in colorectal mechanical nociception. Pain. 2016 Feb;157(2):348-54. doi: 10.1097/j.pain.0000000000000380. PMID: 26447707

Feng B, Zhu Y, La JH, Wills ZP, Gebhart GF. Experimental and computational evidence for an essential role of NaV1.6 in spike initiation at stretch-sensitive colorectal afferent endings. J Neurophysiol. 2015 Apr 1;113(7):2618-34. doi: 10.1152/jn.00717.2014. PMID: 25652923

La JH, Gebhart GF. Condition-specific role of colonic inflammatory molecules in persistent functional colorectal hypersensitivity in the mouse. Neurogastroenterol Motil. 2014 Dec;26(12):1730-42. doi: 10.1111/nmo.12455. PMID: 25307695

Schwartz ES, La JH, Scheff NN, Davis BM, Albers KM, Gebhart GF. TRPV1 and TRPA1 antagonists prevent the transition of acute to chronic inflammation and pain in chronic pancreatitis. J Neurosci. 2013 Mar 27;33(13):5603-11. doi: 10.1523/JNEUROSCI.1806-12.2013. PMID: 23536075

La JH, Feng B, Schwartz ES, Brumovsky PR, Gebhart GF. Luminal hypertonicity and acidity modulate colorectal afferents and induce persistent visceral hypersensitivity. Am J Physiol Gastrointest Liver Physiol. 2012 Oct;303(7):G802-9. doi: 10.1152/ajpgi.00259.2012. PMID: 22859365

Feng B, La JH, Schwartz ES, Gebhart GF. Irritable bowel syndrome: methods, mechanisms, and pathophysiology. Neural and neuro-immune mechanisms of visceral hypersensitivity in irritable bowel syndrome. Am J Physiol Gastrointest Liver Physiol. 2012 May 15;302(10):G1085-98. doi: 10.1152/ajpgi.00542.2011. PMID: 22403791

La JH, Schwartz ES, Gebhart GF. Differences in the expression of transient receptor potential channel V1, transient receptor potential channel A1 and mechanosensitive two pore-domain K+ channels between the lumbar splanchnic and pelvic nerve innervations of mouse urinary bladder and colon. Neuroscience. 2011 Jul 14;186:179-87. doi: 10.1016/j.neuroscience.2011.04.049. PMID: 21549810

La JH, Gebhart GF. Colitis decreases mechanosensitive K2P channel expression and function in mouse colon sensory neurons. Am J Physiol Gastrointest Liver Physiol. 2011 Jul;301(1):G165-74. doi: 10.1152/ajpgi.00417.2010. PMID: 21512155

Complete List of Published Work in My Bibliography