Loren Martin

Assistant Professor



CSB Appointment


Research Areas

Molecular Biology, Neurobiology, Physiology


Ph.D., University of Toronto, 2009

Primary Undergraduate Department


Graduate Programs

Cell & Systems Biology

Research Description

The research in my laboratory aims to understand how painful experiences modify the neural circuits and transmitter/peptide systems related to sensory, emotional, social and cognitive information. Bringing together mouse genetics, electrophysiology, viral tracing, pharmaco- and optogenetics we study the functional interrogation of these circuits within brain and spinal pathways. Our data and the data of others suggests that chronic pain alters synaptic transmission within distinct neural networks and resultant behavioural modifications are dependent upon where in the brain these changes occur. This has led us to investigate the modulation of these circuits by neuropeptides such as oxytocin and opioids to understand their involvement in pain empathy, social approach/avoidance and social analgesia. In a separate line of research, we use novel approaches to understand the learning mechanisms associated with the development of pain and anxiety as well as pain relief. If we are able to understand the processes by which these different functional dimensions of pain perceptions are generated and modified, in particular the circuits encoding negative affective states, then new dynamic frameworks for treating unrelenting chronic pain may be developed.

Contact Information

Office Phone: 905-569-5784
Office: CCT4061
Lab: DV-1076
Lab Phone: 905-828-3785

Mailing Address

Department of Cell & Systems Biology
University of Toronto
3359 Mississauga Road
Mississauga, ON L5L 1C6

Visit lab’s website



Molecular genetic mechanisms of allelic specific regulation of murine Comt expression

Segall SK, Shabalina SA, Meloto CB, Wen X, Cunningham D, Tarantino LM, Wiltshire T, Gauthier J, Tohyama S, Martin LJ, Mogil JS, Diatchenko L
2015, Pain, 156, 1965-77, 26067582

Different immune cells mediate mechanical pain hypersensitivity in male and female mice

Sorge RE, Mapplebeck JC, Rosen S, Beggs S, Taves S, Alexander JK, Martin LJ, Austin JS, Sotocinal SG, Chen D, Yang M, Shi XQ, Huang H, Pillon NJ, Bilan PJ, Tu Y, Klip A, Ji RR, Zhang J, Salter MW, Mogil JS
2015, Nature neuroscience, 18, 1081-3, 26120961

The nicotinic α6 subunit gene determines variability in chronic pain sensitivity via cross-inhibition of P2X2/3 receptors

Wieskopf JS, Mathur J, Limapichat W, Post MR, Al-Qazzaz M, Sorge RE, Martin LJ, Zaykin DV, Smith SB, Freitas K, Austin JS, Dai F, Zhang J, Marcovitz J, Tuttle AH, Slepian PM, Clarke S, Drenan RM, Janes J, Al Sharari S, Segall SK, Aasvang EK, Lai W, Bittner R, Richards CI, Slade GD, Kehlet H, Walker J, Maskos U, Changeux JP, Devor M, Maixner W, Diatchenko L, Belfer I, Dougherty DA, Su AI, Lummis SC, Imad Damaj M, Lester HA, Patapoutian A, Mogil JS
2015, Science translational medicine, 7, 287ra72, 25972004

Reducing social stress elicits emotional contagion of pain in mouse and human strangers

Martin LJ, Hathaway G, Isbester K, Mirali S, Acland EL, Niederstrasser N, Slepian PM, Trost Z, Bartz JA, Sapolsky RM, Sternberg WF, Levitin DJ, Mogil JS
2015, Current biology : CB, 25, 326-32, 25601547

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Olfactory exposure to males, including men, causes stress and related analgesia in rodents

Sorge RE, Martin LJ, Isbester KA, Sotocinal SG, Rosen S, Tuttle AH, Wieskopf JS, Acland EL, Dokova A, Kadoura B, Leger P, Mapplebeck JC, McPhail M, Delaney A, Wigerblad G, Schumann AP, Quinn T, Frasnelli J, Svensson CI, Sternberg WF, Mogil JS
2014, Nature methods, 11, 629-32, 24776635

The interaction between pain and social behavior in humans and rodents

Martin LJ, Tuttle AH, Mogil JS
2014, Current topics in behavioral neurosciences, 20, 233-50, 24557935

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Acutely increasing δGABA(A) receptor activity impairs memory and inhibits synaptic plasticity in the hippocampus

Whissell PD, Eng D, Lecker I, Martin LJ, Wang DS, Orser BA
2013, Frontiers in neural circuits, 7, 146, 24062648

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The Rat Grimace Scale: a partially automated method for quantifying pain in the laboratory rat via facial expressions

Sotocinal SG, Sorge RE, Zaloum A, Tuttle AH, Martin LJ, Wieskopf JS, Mapplebeck JC, Wei P, Zhan S, Zhang S, McDougall JJ, King OD, Mogil JS
2011, Molecular pain, 7, 55, 21801409

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The sedative but not the memory-blocking properties of ethanol are modulated by α5-subunit-containing γ-aminobutyric acid type A receptors

Martin LJ, Zurek AA, Bonin RP, Oh GH, Kim JH, Mount HT, Orser BA
2011, Behavioural brain research, 217, 379-85, 21070817

Short-term memory impairment after isoflurane in mice is prevented by the α5 γ-aminobutyric acid type A receptor inverse agonist L-655,708

Saab BJ, Maclean AJ, Kanisek M, Zurek AA, Martin LJ, Roder JC, Orser BA
2010, Anesthesiology, 113, 1061-71, 20966663

Alpha5GABAA receptor activity sets the threshold for long-term potentiation and constrains hippocampus-dependent memory

Martin LJ, Zurek AA, MacDonald JF, Roder JC, Jackson MF, Orser BA
2010, The Journal of neuroscience : the official journal of the Society for Neuroscience, 30, 5269-82, 20392949

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The physiological properties and therapeutic potential of alpha5-GABAA receptors

Martin LJ, Bonin RP, Orser BA
2009, Biochemical Society transactions, 37, 1334-7, 19909271

alpha5 Subunit-containing GABA(A) receptors mediate a slowly decaying inhibitory synaptic current in CA1 pyramidal neurons following Schaffer collateral activation

Vargas-Caballero M, Martin LJ, Salter MW, Orser BA, Paulsen O
2010, Neuropharmacology, 58, 668-75, 19941877

Etomidate targets alpha5 gamma-aminobutyric acid subtype A receptors to regulate synaptic plasticity and memory blockade

Martin LJ, Oh GH, Orser BA
2009, Anesthesiology, 111, 1025-35, 19809285

Suppression of hippocampal TRPM7 protein prevents delayed neuronal death in brain ischemia

Sun HS, Jackson MF, Martin LJ, Jansen K, Teves L, Cui H, Kiyonaka S, Mori Y, Jones M, Forder JP, Golde TE, Orser BA, Macdonald JF, Tymianski M
2009, Nature neuroscience, 12, 1300-7, 19734892

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Alpha5GABAA receptors regulate the intrinsic excitability of mouse hippocampal pyramidal neurons

Bonin RP, Martin LJ, MacDonald JF, Orser BA
2007, Journal of neurophysiology, 98, 2244-54, 17715197

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Alpha5GABAA receptors mediate the amnestic but not sedative-hypnotic effects of the general anesthetic etomidate

Cheng VY, Martin LJ, Elliott EM, Kim JH, Mount HT, Taverna FA, Roder JC, Macdonald JF, Bhambri A, Collinson N, Wafford KA, Orser BA
2006, The Journal of neuroscience : the official journal of the Society for Neuroscience, 26, 3713-20, 16597725

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Modulation of NMDA receptors by pituitary adenylate cyclase activating peptide in CA1 neurons requires G alpha q, protein kinase C, and activation of Src

Macdonald DS, Weerapura M, Beazely MA, Martin L, Czerwinski W, Roder JC, Orser BA, MacDonald JF
2005, The Journal of neuroscience : the official journal of the Society for Neuroscience, 25, 11374-84, 16339032

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Influence of a complex magnetic field application in rats upon thermal nociceptive thresholds: the importance of polarity and timing

Martin LJ, Koren SA, Persinger MA
2004, The International journal of neuroscience, 114, 1259-76, 15370185

Alpha2-adrenergic inhibition prevents the accompanied anticonvulsant effect of swim stress on behavioral convulsions induced by lithium and pilocarpine

Galic MA, Fournier NM, Martin LJ
2004, Pharmacology, biochemistry, and behavior, 79, 309-16, 15501307

Thermal analgesia induced by 30-min exposure to 1 microT burst-firing magnetic fields is strongly enhanced in a dose-dependent manner by the alpha2 agonist clonidine in rats

Martin LJ, Persinger MA
2004, Neuroscience letters, 366, 226-9, 15276252

Thermal analgesic effects from weak, complex magnetic fields and pharmacological interactions

Martin LJ, Koren SA, Persinger MA
2004, Pharmacology, biochemistry, and behavior, 78, 217-27, 15219761

Chronic administration of the L-type calcium channel blocker nimodipine can facilitate the acquisition of sequence learning in a radial-arm maze

Martin LJ, Fournier NM, Galic MA, Emond MH
2004, Behavioural pharmacology, 15, 133-9, 15096913

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Spatial heterogeneity not homogeneity of the magnetic field during exposures to complex frequency-modulated patterns facilitates analgesia

Martin LJ, Persinger MA
2003, Perceptual and motor skills, 96, 1005-12, 12831282

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Learning and memory in agmatine-treated rats

McKay BE, Lado WE, Martin LJ, Galic MA, Fournier NM
2002, Pharmacology, biochemistry, and behavior, 72, 551-7, 12175451

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