• Immunobiology of microglial cells in the central nervous system and retina under normal and experimental conditions e.g. following hypoxic exposures.
• Hypoxia induced mechanisms underlying damage to the periventriclular white matter, choroid plexus in the lateral ventricles of the brain and the developing retina.

Cellular and Molecular mechanisms of hypoxic damage to the developing brain with special reference to microglia cells.

• Hypoxia is the common tissue end-point in a number of neurological diseases. In the developing brain, cerebral hypoxia contributes significantly to neonatal mortality and long-term neurodevelopmental deficits such as cerebral palsy and mental retardation. Damage to the periventricular white matter peripheral to the lateral ventricles is the predominant form of injury in hypoxic conditions.
• Hypoxia is a potent inducer of inflammation and enhanced vascular permeability. Since microglial cells are the macrophagic and immune effector cells in the central nervous system, their role in the production of inflammatory cytokines and the signaling pathway involved in such production are being investigated in my laboratory in both the developing brain. Along with this, other factors such as increased production of glutamate, inducible nitric oxide synthase and reactive oxygen species are being investigated. The main neuropathological feature of hypoxic periventricular white matter injury in the developing brain is death of oligodendrocytes and axonal degeneration resulting in delayed myelination or hypomyelination. The role of microglial cells in such damage through production of toxic factors mentioned above is being investigated. Microglial cells have also been implicated in inducing damage to the blood brain barrier as they are closely associated with the brain capillaries. This is also within my investigative field.

Cellular and Molecular mechanisms of hypoxic damage to the developing retina (in collaboration with Singapore Eye Research Institute) The retina is developmentally an extension of the brain and is extremely sensitive to oxygen fluctuations. Retinal ganglion cells and glial cells such as microglial cells and Müller cells respond to the changes induced by hypoxia. The involvement of microglial cells in inducing retinal ganglion cell death through production of inflammatory cytokines and other factors is being investigated.

• V. Sivakumar, W.S. Foulds, C.D. Luu,  E.A. Ling, C. Kaur*. Retinal ganglion cell death is induced by microglia derived proinflammatory cytokines in the hypoxic neonatal retina. Journal of Pathology, 2011 (in press)

• Kaur C*, Sivakumar V, Ling EA. Hypoxia induced cellular and vascular changes in the nucleus tractus solitarius and ventrolateral medulla. Journal of Neuropathology and Experimental Neurology, 2011;70(3):201-217

• Murugan M, V Sivakumar, Lu J, Ling EA, Kaur C*. Expression of N-methyl D-aspartate receptor subunits in amoeboid microglia mediates production of nitric oxide via NF-ĸB signalling pathway and oligodendrocyte cell death in hypoxic postnatal rats. Glia 2011;59(4):521-39

• Deng YY, Lu J, Ling EA, Kaur C*. Microglia-derived macrophage colony stimulating factor promotes generation of proinflammatory cytokines by astrocytes in the periventricular white matter in the hypoxic neonatal brain. Brain Pathology, 2010 Sep;20(5):909-25

• Sivakumar V, Ling EA, Lu J, Kaur C*. Role of glutamate and its receptors and insulin-like growth factors in hypoxia induced periventricular white matter injury. Glia 2010, Apr;58(5):507-23.

• Kaur C*, Sivakumar V, Foulds WS, Luu CD, Ling EA. Cellular and vascular changes in the retina of neonatal rats following an acute exposure to hypoxia. Investigative Ophthalmology and Visual Science 2009 50(11):5364-74

• Kaur C*, Foulds WS, Ling EA. Blood retinal barrier in hypoxic ischaemic conditions: basic concepts, clinical features and management. Progress in Retinal and Eye Research, 2008 , 27(6):622-647

• Deng YY , Lu J, Ling EA, Kaur C* Monocyte chemoattractant protein-1 (MCP-1) produced via NF-kappaB signaling pathway mediates migration of amoeboid microglia in the periventricular white matter in hypoxic neonatal rats. Glia. 2009 Apr 15;57(6):604-21.
• Kaur C*, Sivakumar V, Yip G.W, Ling EA. Expression of Syndecan-2 in the amoeboid microglial cells and its involvement in inflammation in the hypoxic developing brain. Glia 2009 Feb;57(3):336-49

• Kaur C*, Sivakumar V, Lu J, Tang FR, Ling EA.  Melatonin Attenuates Hypoxia-Induced Ultrastructural Changes and Increased Vascular Permeability in the Developing Hippocampus. Brain Pathol. 2008, 18(4):533-547.

• Deng YY, Lu J, Sivakumar V, Ling EA, Kaur C*.Amoeboid microglia in the periventricular white matter induces oligodendrocyte damage through expression of proinflammatory cytokines via MAP kinase signaling pathway in hypoxic neonatal rats. Brain Pathology, 2008;  18(3):387-400

• Kaur C, Ling EA. Periventricular white matter damage in the hypoxic neonatal brain; role of microglia cells. Prog Neurobiol. 2009 Apr; 87(4):264-80.
• Kaur C, Sivakumar V, Zhang Y, Lu J, Foulds WS, Ling EA. Blood-retinal barrier disruption and ultrastuctural changes in the hypoxic retina in adult rats: The beneficial effect of melatonin administration. J Pathol. 2007;212(4):429-439.
• Kaur C, Sivakumar V, Lu J, Ling EA. Increased vascular permeability and nitric oxide production in response to hypoxia in the pineal gland. J Pineal Res. 2007 ;42(4):338-349.
• Kaur C, Sivakumar V , Ling EA. Expression of tranferrin receptors in the pineal gland of postnatal and adult rats and its alteration in hypoxia and melatonin treatment. Glia. 2007;55(3):263-273
• Kaur C, Sivakumar V, Zhang Y, Ling EA. Hypoxia-induced astrocytic reaction and increased vascular permeability in the rat cerebellum. Glia. 2006;54(8):826-839
• Kaur C, Sivakumar V, Ang LS, Sunderasan L. Hypoxic damage to the periventricular white matter in neonatal brain: role of vascular endothelial growth factor, nitric oxide and excitotoxicity.  Journal of Neurochemistry 2006, 98:1200-1216
• Kaur C, Sivakumar V, Foulds WS. Early response of neurons and glial cells to hypoxia in the retina. Investigative Ophthalmology and Visual Science, 2006 ;47(3):1126-1141
• Kaur C, Sivakumar V, Dheen ST, Ling EA. Insulin-like growth factor I and II expression and modulation in amoeboid microglial cells by lipopolysaccharide and retinoic acid. Neuroscience. 2006;138(4):1233-1244

• Teaching Excellence Award , National University of Singapore, 2006
• Long Service Award, National University of Singapore, 2007
• Research Excellence Award, National University of Singapore, 2010
• Top Reviewer, Brain Research, Elsevier,  2010
• Top Cited Paper, Progress in Retinal and Eye Research, 2010

• Section Head, Anatomy and Development,  BMC Neuroscience
• Adjunct Senior Research Fellow, Singapore Eye Research Institute

• Member, International Society of Neurochemistry
• Member, Society for Neuroscience, USA
• Member, Neurotoxicity Society, USA
• Member, International Brain Research organization
• Member, Singapore Neuroscience Association
• Member, Microscopy Society Singapore