null Samuel David, PhD

Senior Scientist, RI-MUHC, Montreal General Hospital site

Brain Repair and Integrative Neuroscience (BRaIN) Program

Centre for Translational Biology

Professor, Department of Neurology and Neurosurgery, Faculty of Medicine and Health Sciences, McGill University

Department of Medicine, Division of Neurology, MUHC



multiple sclerosis • spinal cord injury • nerve injury • oxidative damage • iron metabolism • inflammation

Research Focus

My research focuses on how metals, in particular iron, induce damage in the nervous system in neurological conditions such as multiple sclerosis (MS) and spinal cord injury. In brain or spinal cord trauma, iron is released from hemoglobin found in red blood cells, which are present due to bleeding. We are studying new ways in which iron causes such damage and testing ways to prevent this damage and promote recovery. In other conditions like MS, iron stores within cells in the brain are mobilized and released to cause damage. We are studying how to prevent this and develop new treatments for MS. Iron is not always bad; in fact, the right amount of iron is required for nerve cells to grow. Therefore, another area of work is on how nerve fibers acquire iron for regeneration.

Selected Publications

Click on Pubmed to see my current publications list

  • Greenhalgh AD, David S. and Bennett FC (2019) Immune cell regulation of glia during CNS injury and disease. Nature Reviews Neuroscience 21(3):139-152. PMID: 32042145.

  • Greenhalgh AD, Zarruk JG, Healy, LM, Baskar Jesudasan SJ, Jhelum P, Salmon CK, Formanek A, Russo MV, Antel JP, McGavern DB, McColl BW, David S. (2019) Peripherally derived macrophages modulate microglial function to reduce inflammation after CNS injury. PLoS Biology 16(10):e2005264. PMID: 30332405.

  • Zarruk JG**, Greenhalgh AD** and David S (2018) Microglia and macrophages differ in their inflammatory profile after permanent brain ischemia. Exp Neurol. 301: 120-132.

  • David, S. Greenhalgh, A.G. and Kroner, A. (2015) Macrophage and Microglial Plasticity in the Injured Spinal Cord. Neuroscience 307:311-8. PMID: 26342747.

  • Kroner A, **Greenhalgh AD, **Zarruk JG, *Passos Dos Santos R, Gaestel M, David S (2014). TNF and increased intracellular iron alter macrophage polarization to a detrimental M1 phenotype in the injured spinal cord. Neuron 83:1098-116. PMID: 25132469.