Dr. Selva Baltan

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University of Washington
School of Medicine
Neurology
Research Assistant ProfessorAppointed: 2005
Professional Headshot of Selva Baltan

Mailing Address

Harborview Medical Center
Research and Training Building
325 Ninth Avenue
Box 359665
Seattle, Washington 98104
United States

Contact Information

Phone: (206) 897-5294
Fax: (206) 897-5432
selva@u.washington.edu

Qualifications

Ph.D., McGill University, Physiology, 1998.
M.D., Hacettepe University, Medicine, 1990.

Expertise and Research Interests

Please note that I have published as Tekkok in the past and publish as BALTAN since 2006. I apologize for any inconvenience and appreciate your attention to this legal matter.

My research focuses on mechanisms of brain cell damage following stroke in white matter. Experimental approaches include optic nerve and corpus callosum slice models, together with electrophysiological recordings and advanced optical microscopy techniques such as fluorescence immunocytochemistry, and confocal microscopy as well as biochemical methods. Hippocampal slices are frequently used to compare gray and white matter susceptibility and mechanisms of injury.

Despite recent emerging interest in white matter, relatively little is known about how to approach white matter injury during hypoxic/ischemic, traumatic or demyelinating disorders. We discovered that glutamate, which was accepted to be an exclusive gray matter neurotransmitter, is indeed released in white matter during ischemia. Interestingly, overactivation of glutamate receptors is toxic not only to neurons, but also to oligodendrocytes, the myelin-forming glial cells. We also investigated the mechanisms of axonal injury in the optic nerve or corpus callosum slices to identify the intimate relationship between oligodendrocytes and their myelinated axons.

In addition, we study the role of glucose and glycogen stores in white matter during aglycemia. We showed that, during aglycemia, glycogen is converted to lactate and is used as an alternative fuel by axons to maintain function. During intense activity glycogen seems to be the choice of substrate to derive energy and maintain function. Glycogen stores in white matter could be modified through insulin-receptor dependent and independent mechanisms. We are investigating the role of glycogen in white matter to bring new approaches to the understanding of central nervous system complications of diabetes mellitus.

My main project is to critically explore the mechanisms of ischemic injury in aging white matter to finally meet the daunting challenge of offering effective therapeutic approaches to treating stroke in the clinical setting. Previous approaches to treatment of stroke were directed only to the gray matter of brain excluding the white matter. Most of these studies utilized young animals. Although we showed that white matter is relatively more resistant to anoxia, white matter is intrinsically vulnerable to ischemic injury. This vulnerability is age dependent and shows regional specificity. These mechanistic approaches have direct implications for other white matter diseases including, spinal cord injury, multiple sclerosis, cerebral palsy, periventricular leukomalacia, Alzheimer's Disease and age-related dementia.

Keywords

COS Keywords:

Brain Injury, Confocal Microscopy, Demyelinating Diseases, Electrophysiology, Evoked Potential, Immunofluorescence, Ischemia, Neurology, Neurophysiology, Physiology, Stroke.

Additional Terms:

Axon, Demyelinating Diseases, Evoked Potentials, Glial Cells, Immunofluorescence, Neurophysiology, Stroke, White Matter Injury.

Languages

(Reading, Writing, Speaking)

English: (Fluent, Fluent, Fluent)
Turkish: (Fluent, Fluent, Fluent)
French: (Fluent, Functional, Functional)

Memberships

American Stroke Association, Stroke Council
Society for Neuroscience
Turkish American Scientists and Scholars Association

Honors and Awards

2000-2001, AHA Fellow, American Stroke Association
1997-1998, MRC Scholarship, Medical Research Council of Canada, Physiology
1984-1990, Medicine Scholarship, School of Medicine (English Curriculum), Hacettepe University
1988, Internal Medicine Clerkship, Leiden Academic Hospital
1997, First Prize, Physiology, McGill University

Previous Positions

2003-2004, Acting Assistant Professor, University of Washington, School of Medicine, Neurology
2000-2001, American Heart and Stroke Fellow, Washington University, Medicine, Neurology, Center for the Study of Nervous System Injury
1999-2000, McDonnel Cellular and Molecular Neurobiology Fellow, Washington University, Medicine, Neurology, Center for Study of Nervous System Injury
1998-1999, Research Associate, Washington University, Medicine, Neurology
1991-1994, Resident, Hacettepe University, Medicine, Physiology
1990-1991, Resident, Ankara Numune Hospital, Cardiovascular and Thoracic Surgery

Funding Received

  • American Heart Association (AHA): Aging and CNS White Matter Ischemic Injury, $260,000, 2006 to 2010.
  • Unites Spinal Association: Pathophysiology of CNS White Matter Injury, $60,000/year, 2004 to 2006.
  • Eastern Paralyzed Veterans Association (EPVA): Ca During White Matter Injury, $60,000, 2003 to 2004.
  • American Heart Association (AHA): Ischemic White Matter Injury, $28,000/year, 2000 to 2002.
  • McDonnell Center for Cellular and Molecular Neurobiology: McDonnell Neurobiology Fellowship, $27,000/year, 1999 to 2000.
  • Quebec and French Community of Belgium: Improvement of Technology Grant, 1997 to 1998.
  • Medical Research Council of Canada: Medical Research Council of Canada Scholarship, $16,500/year, 1997 to 1998.
  • Higher Educational Council of Turkey: Post-graduate Study Scholarship, Full Tuition and Fee, 1994 to 1998.
  • Hacettepe University: Hacettepe Medicine Scholarship, Full Tuition and Fee, 1984 to 1990.
  • Medical Student Exchange Program: Clerkship in Internal Medicine, Leiden Academic Hospital, Holland, $3,000, 1984 to .

Publications

  • Baltan S (Apr 2009) Ischemic injury to white matter: an age-dependent process., The Neuroscientist : a review journal bringing neurobiology, neurology and psychiatry, 15 (2), 126-33 Abstract
  • Ransom BR, Baltan SB (Feb 2009) Axons get excited to death., Annals of neurology, 65 (2), 120-1 Abstract
  • Baltan S, Besancon EF, Mbow B, Ye Z, Hamner MA, Ransom BR (Feb 2008) White matter vulnerability to ischemic injury increases with age because of enhanced excitotoxicity., The Journal of neuroscience : the official journal of the Society for Neuroscience, 28 (6), 1479-89 Abstract
  • Tekkök SB, Ye Z, Ransom BR (Sep 2007) Excitotoxic mechanisms of ischemic injury in myelinated white matter., Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 27 (9), 1540-52 Abstract
  • Baltan S (2006) Surviving anoxia: a tale of two white matter tracts., Critical reviews in neurobiology, 18 (1-2), 95-103 Abstract
  • Tekkok SB, Brown AM, Westenbroek R, Pellerin L, Ransom BR (Sep 2005) Transfer of glycogen-derived lactate from astrocytes to axons via specific monocarboxylate transporters supports mouse optic nerve activity., Journal of Neuroscience Research, 81 (5), 644-52 Abstract
  • Tekkok SB, Faddis BT, Goldberg MP (Jul 2005) AMPA/kainate receptors mediate axonal morphological disruption in hypoxic white matter., Neuroscience Letters, 382 (3), 275-9 Abstract
  • Selva Baltan Tekkok, Bruce R Ransom (2005) Regional differences in excitotoxic white matter injury., International Proceedings, May (22-25)
  • Baltan Tekkok., S and Ransom, B.R., Anoxia effects on central nervous sytem function and survival: regional differences, Neurochemistry Research, 29(11), 2163-2169, Nov 2004
  • Brown AM, Baltan Tekkok S, Ransom BR, Energy transfer from astrocytes to axons: the role of CNS glycogen, Neurochemistry International, 45(4), 529-36, Sep 2004 Abstract
  • Baltan Tekkok., S. and Ransom, B.R., Glial-neuronal intercations and signaling:an introduction, in Glia and Neuron Signaling (Hatton, G and Parpura V editors), 1-20, 2004
  • Brown, A.M., Baltan Tekkok, S., and Ransom, B.R., Glia-neuronal intrecations and brain energy metabolism, In Glia nad Neuron Signaling (Hatton., G and Parpura, V. Editors), 279-296, 2004
  • Tekkok SB, Brown AM, Ransom BR, Axon function persists during anoxia in mammalian white matter, Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism., 23(11), 1340-7, Nov 2003 Abstract
  • Brown AM, Tekkok SB, Ransom BR, Glycogen regulation and functional role in mouse white matter, The Journal of Physiology, 549(Pt 2), 501-12, Jun 2003 Abstract
  • Ye ZC, Wyeth MS, Baltan-Tekkok S, Ransom BR, Functional hemichannels in astrocytes: a novel mechanism of glutamate release, The Journal of Neuroscience : the Official Journal of the Society for Neuroscience., 23(9), 3588-96, May 2003 Abstract
  • Brown AM, Tekkok SB, Ransom BR, Hypoglycemia and white matter: pathophysiology of axon injury and role of glycogen, Diabetes, Nutrition & Metabolism, 15(5), 290-3; discussion 29, Oct 2002 Abstract
  • Tekkok SB, Godfraind JM, Krnjevic K, Moderate hypoglycemia aggravates effects of hypoxia in hippocampal slices from diabetic rats, Neuroscience, 113(1), 11-21, 2002 Abstract
  • Underhill, S.M., Baltan Tekkok, S., Hasbani, J.M., and Goldberg, M.P., Cellular mechanisms of white matter ischemia- what can we learn from culture models?, Cerebrovascular Disease (Chan, P Editor) Cambridge, MA, 95-110, 2002
  • Tekkok SB, Goldberg MP, Ampa/kainate receptor activation mediates hypoxic oligodendrocyte death and axonal injury in cerebral white matter, The Journal of Neuroscience : the Official Journal of the Society for Neuroscience., 21(12), 4237-48, Jun 2001 Abstract
  • Godfraind JM, Tekkok SB, Krnjevic K, Hypoxia on hippocampal slices from mice deficient in dystrophin (mdx) and isoforms (mdx3cv), Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism., 20(1), 145-52, Jan 2000 Abstract
  • Tekkok S, Krnjevic K, Diabetes mellitus preserves synaptic plasticity in hippocampal slices from middle-aged rats, Neuroscience, 91(1), 185-91, 1999 Abstract
  • Tekkok S, Medina I, Krnjevic K, Intraneuronal [Ca2+] changes induced by 2-deoxy-D-glucose in rat hippocampal slices, Journal of Neurophysiology, 81(1), 174-83, Jan 1999 Abstract
  • Tekkok S, Kriz J, Padjen AL, Krnjevic K, Higher sensitivity of CA1 synapses to aglycemia in streptozotocin-diabetic rats is age-dependent, Brain Research, 813(2), 268-73, Dec 1998 Abstract
  • Zhao YT, Tekkok S, Krnjevic K, 2-Deoxy-D-glucose-induced changes in membrane potential, input resistance, and excitatory postsynaptic potentials of CA1 hippocampal neurons, Canadian Journal of Physiology and Pharmacology, 75(5), 368-74, May 1997 Abstract
  • Krnjevic, K., Tekkok, S., Medina, I., and Zhao, Y.T., Poor correlation between post-synatic [Ca2+]i increases and LTP induced by 2-deoxuglucose in rat hippocampal neurons, Neurophysiology (Kiev), 29, 312-322, 1997
  • Tekkok S, Krnjevic K, Calcium dependence of LTP induced by 2-deoxyglucose in CA1 neurons, Journal of Neurophysiology, 76(4), 2343-52, Oct 1996 Abstract
  • Tekkok S, Krnjevic K, Long-term potentiation in hippocampal slices induced by temporary suppression of glycolysis, Journal of Neurophysiology, 74(6), 2763-6, Dec 1995 Abstract
  • Tekkok IH, Tekkok S, Ozcan OE, Erbengi T, Erbengi A, Preventive effect of intracisternal heparin for proliferative angiopathy after experimental subarachnoid haemorrhage in rats, Acta Neurochirurgica, 127(1-2), 112-7, 1994 Abstract
  • Tekkok, S. and Dikmenoglu N., Physiological control mechanisms of arterial blood pressure, Hypertension Bulletin (Bayer), 32, 38-47, 1993
  • Tekkok, S., Dikmenoglu, N., Tekkok, I.H., Balkanci, B., Yorukan, Y., and Andac, O., The effects of heparin treatment on the oxidative damage in experimental rat subarachnoid haemorrhage, Physiology Bulletin, 4(4), 93-97, 1993
  • Tekkok, S., and Dikmenoglu, N., Comparative analysis of Na-pentobarbital and ketamine anaesthesia, Physiology Bulletin, 3(4), 147-155, 1993

Profile Details

Last Verified: 12/21/2009

COS Expertise ID #1174904
Reference this profile directly: http://myprofile.cos.com/selvabaltan