Ivan Tkac

Summary

Affiliation: University of Minnesota
Country: USA

Publications

  1. ncbi request reprint Developmental and regional changes in the neurochemical profile of the rat brain determined by in vivo 1H NMR spectroscopy
    Ivan Tkac
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 50:24-32. 2003
  2. ncbi request reprint In vivo 1H NMR spectroscopy of rat brain at 1 ms echo time
    I Tkac
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis 55455, USA
    Magn Reson Med 41:649-56. 1999
  3. ncbi request reprint In vivo 1H NMR spectroscopy of the human brain at 7 T
    I Tkac
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 46:451-6. 2001
  4. pmc In vivo 1H NMR spectroscopy of the human brain at high magnetic fields: metabolite quantification at 4T vs. 7T
    Ivan Tkac
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 62:868-79. 2009
  5. ncbi request reprint Highly resolved in vivo 1H NMR spectroscopy of the mouse brain at 9.4 T
    Ivan Tkac
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis 55455, USA
    Magn Reson Med 52:478-84. 2004
  6. ncbi request reprint In vivo effect of chronic hypoxia on the neurochemical profile of the developing rat hippocampus
    Lakshmi Raman
    Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
    Brain Res Dev Brain Res 156:202-9. 2005
  7. ncbi request reprint Brain energy metabolism and neurotransmission at near-freezing temperatures: in vivo (1)H MRS study of a hibernating mammal
    Pierre Gilles Henry
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN 55455, USA
    J Neurochem 101:1505-15. 2007
  8. pmc Neurochemical changes in the developing rat hippocampus during prolonged hypoglycemia
    Raghavendra Rao
    Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA
    J Neurochem 114:728-38. 2010
  9. pmc Perinatal iron deficiency predisposes the developing rat hippocampus to greater injury from mild to moderate hypoxia-ischemia
    Raghavendra Rao
    Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 27:729-40. 2007
  10. pmc Iron supplementation dose for perinatal iron deficiency differentially alters the neurochemistry of the frontal cortex and hippocampus in adult rats
    Raghavendra Rao
    Department of Pediatrics, Neonatology Division, University of Minnesota, Minneapolis, MN, USA
    Pediatr Res 73:31-7. 2013

Detail Information

Publications39

  1. ncbi request reprint Developmental and regional changes in the neurochemical profile of the rat brain determined by in vivo 1H NMR spectroscopy
    Ivan Tkac
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 50:24-32. 2003
    ..The current data may serve as a reference for studies focused on developmental defects and pathologies using neonatal rat models...
  2. ncbi request reprint In vivo 1H NMR spectroscopy of rat brain at 1 ms echo time
    I Tkac
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis 55455, USA
    Magn Reson Med 41:649-56. 1999
    ..At 9.4 T, peaks close to the water were observed, including the H-1 of alpha-D-glucose at 5.23 ppm and a tentative H-1 resonance of glycogen at 5.35 ppm...
  3. ncbi request reprint In vivo 1H NMR spectroscopy of the human brain at 7 T
    I Tkac
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 46:451-6. 2001
    ..Characteristic spectral patterns of metabolites, e.g., myo-inositol and taurine, were discernible in the in vivo spectra, which facilitated an unambiguous signal assignment...
  4. pmc In vivo 1H NMR spectroscopy of the human brain at high magnetic fields: metabolite quantification at 4T vs. 7T
    Ivan Tkac
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 62:868-79. 2009
    ....
  5. ncbi request reprint Highly resolved in vivo 1H NMR spectroscopy of the mouse brain at 9.4 T
    Ivan Tkac
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis 55455, USA
    Magn Reson Med 52:478-84. 2004
    ..4 T can provide precise biochemical information from distinct regions of the mouse brain noninvasively that can be used for monitoring of disease progression and treatment as well as phenotyping in transgenic mice models...
  6. ncbi request reprint In vivo effect of chronic hypoxia on the neurochemical profile of the developing rat hippocampus
    Lakshmi Raman
    Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
    Brain Res Dev Brain Res 156:202-9. 2005
    ..The altered hippocampal neurochemistry during its development may underlie some of the cognitive deficits present in human infants at risk of chronic hypoxia...
  7. ncbi request reprint Brain energy metabolism and neurotransmission at near-freezing temperatures: in vivo (1)H MRS study of a hibernating mammal
    Pierre Gilles Henry
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN 55455, USA
    J Neurochem 101:1505-15. 2007
    ....
  8. pmc Neurochemical changes in the developing rat hippocampus during prolonged hypoglycemia
    Raghavendra Rao
    Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA
    J Neurochem 114:728-38. 2010
    ..Compensatory neurochemical changes maintain energy homeostasis during prolonged hypoglycemia in the developing hippocampus...
  9. pmc Perinatal iron deficiency predisposes the developing rat hippocampus to greater injury from mild to moderate hypoxia-ischemia
    Raghavendra Rao
    Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 27:729-40. 2007
    ....
  10. pmc Iron supplementation dose for perinatal iron deficiency differentially alters the neurochemistry of the frontal cortex and hippocampus in adult rats
    Raghavendra Rao
    Department of Pediatrics, Neonatology Division, University of Minnesota, Minneapolis, MN, USA
    Pediatr Res 73:31-7. 2013
    ..Whether high-dose iron supplementation prevents these deficits is yet to be determined...
  11. pmc Metabolic and hemodynamic events after changes in neuronal activity: current hypotheses, theoretical predictions and in vivo NMR experimental findings
    Silvia Mangia
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 29:441-63. 2009
    ..In addition, the cellular and network mechanisms that characterize different types of increased and suppressed neuronal activity will be considered within the sensitivity-constraints of MRS and MRI...
  12. ncbi request reprint Sustained neuronal activation raises oxidative metabolism to a new steady-state level: evidence from 1H NMR spectroscopy in the human visual cortex
    Silvia Mangia
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 27:1055-63. 2007
    ....
  13. pmc Homeostatic adaptations in brain energy metabolism in mouse models of Huntington disease
    Ivan Tkac
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 32:1977-88. 2012
    ..In contrast, these parameters were normal in R6/2 mice. These results suggest that early changes in brain energy metabolism are followed by compensatory shifts to maintain energetic homeostasis from early ages through manifest disease...
  14. pmc Fetal and neonatal iron deficiency causes volume loss and alters the neurochemical profile of the adult rat hippocampus
    Raghavendra Rao
    Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
    Nutr Neurosci 14:59-65. 2011
    ..The objective of the present study was to determine the long-term effects of perinatal iron deficiency and its treatment on hippocampal anatomy and neurochemistry in formerly iron-deficient young adult rats...
  15. ncbi request reprint Dynamics of lactate concentration and blood oxygen level-dependent effect in the human visual cortex during repeated identical stimuli
    Silvia Mangia
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA
    J Neurosci Res 85:3340-6. 2007
    ..Alternative possibilities that could account for an adaptation of [Lac] changes are also discussed...
  16. pmc Frequency offset dependence of adiabatic rotating frame relaxation rate constants: relevance to MRS investigations of metabolite dynamics in vivo
    Silvia Mangia
    Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
    NMR Biomed 24:807-14. 2011
    ..We conclude that differences in adiabatic R(1ρ) and R(2ρ) values of human brain metabolites are not a result of their chemical shifts, but instead reflect differences in dynamics...
  17. ncbi request reprint Detection of an antioxidant profile in the human brain in vivo via double editing with MEGA-PRESS
    Melissa Terpstra
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 56:1192-9. 2006
    ..GSSG contributions to the DEW MEGA-PRESS GSH resonance (3.0 ppm) are negligible under physiologic conditions, and would be evidenced by a distinct GSSG resonance (3.3 ppm) at exceptionally high concentrations...
  18. pmc Neurochemical profile of patients with type 1 diabetes measured by ¹H-MRS at 4 T
    Silvia Mangia
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 33:754-9. 2013
    ..No other differences in metabolites were observed between subjects with T1DM and controls...
  19. pmc Neurochemical alterations in spinocerebellar ataxia type 1 and their correlations with clinical status
    GULIN OZ
    Center for MR Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Mov Disord 25:1253-61. 2010
    ..These data demonstrate that (1)H MRS biomarkers can be utilized to noninvasively assess neuronal and glial status in individual ataxia patients...
  20. ncbi request reprint Brain glucose concentrations in healthy humans subjected to recurrent hypoglycemia
    Amy B Criego
    Department of Pediatrics, University of Minnesota Medical School, Minneapolis, USA
    J Neurosci Res 82:525-30. 2005
    ..1 +/- 0.8 vs. 4.5 +/- 0.5 mumol/g wet weight, respectively, P = 0.05). These observations suggest that brain glucose transport or metabolism is not altered following short episodes of recurrent hypoglycemia in healthy human volunteers...
  21. ncbi request reprint Quantification of vitamin C in the rat brain in vivo using short echo-time 1H MRS
    Melissa Terpstra
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 55:979-83. 2006
    ..Ascorbate concentrations measured using STEAM decreased with increasing postnatal rat age, in agreement with published brain ascorbate concentrations measured in vitro using high-performance liquid chromatography (HPLC)...
  22. pmc Regional neurochemical profiles in the human brain measured by ¹H MRS at 7 T using local B₁ shimming
    Uzay E Emir
    Center for Magnetic Resonance Research, Department of Radiology, School of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
    NMR Biomed 25:152-60. 2012
    ....
  23. pmc Postnatal morphine administration alters hippocampal development in rats
    Christopher M Traudt
    Department of Pediatrics, Division of Neonatology, University of Minnesota, Minneapolis, Minnesota, USA
    J Neurosci Res 90:307-14. 2012
    ..Bromodeoxyuridine labeling in the dentate gyrus was decreased by 60-70% in morphine-exposed rats. These results suggest that recurrent morphine administration during brain development alters hippocampal structure...
  24. pmc Region-specific changes in ascorbate concentration during rat brain development quantified by in vivo (1)H NMR spectroscopy
    Melissa Terpstra
    Radiology and Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
    NMR Biomed 23:1038-43. 2010
    ....
  25. ncbi request reprint Proton MRS of the unilateral substantia nigra in the human brain at 4 tesla: detection of high GABA concentrations
    GULIN OZ
    Center for MR Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 55:296-301. 2006
    ..These findings establish the feasibility of obtaining a neurochemical profile of the unilateral human SN by single-voxel spectroscopy in small volumes...
  26. pmc Gestational and lactational iron deficiency alters the developing striatal metabolome and associated behaviors in young rats
    Kay L Ward
    Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
    J Nutr 137:1043-9. 2007
    ..These novel data imply that alterations in the metabolite profile of the striatum likely influence later neural functioning in early iron deficiency...
  27. ncbi request reprint 1H-localized broadband 13C NMR spectroscopy of the rat brain in vivo at 9.4 T
    Pierre Gilles Henry
    Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis Minnesota
    Magn Reson Med 50:684-92. 2003
    ..This unprecedented amount of information will be useful for metabolic modeling studies aimed at understanding brain energy metabolism and neurotransmission in the rodent brain...
  28. ncbi request reprint Perinatal iron deficiency alters the neurochemical profile of the developing rat hippocampus
    Raghavendra Rao
    Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
    J Nutr 133:3215-21. 2003
    ..An altered neurochemical profile of the developing hippocampus may underlie some of the cognitive deficits observed in human infants with perinatal iron deficiency...
  29. pmc Iron is essential for neuron development and memory function in mouse hippocampus
    ERIK S CARLSON
    Medical Scientist Training Program, University of Minnesota Medical School, Minneapolis, MN 55455, USA
    J Nutr 139:672-9. 2009
    ..Deletion of Slc11a2 disrupts hippocampal neuronal development and spatial memory behavior...
  30. ncbi request reprint Ultrahigh field magnetic resonance imaging and spectroscopy
    Kamil Ugurbil
    Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN 55455, USA
    Magn Reson Imaging 21:1263-81. 2003
  31. pmc Cortical metabolites as biomarkers in the R6/2 model of Huntington's disease
    Lori Zacharoff
    Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Cereb Blood Flow Metab 32:502-14. 2012
    ..Thus, neurochemical changes precede volume shrinkage and become potential biomarkers for HD mouse models...
  32. pmc Determination of oxidative glucose metabolism in vivo in the young rat brain using localized direct-detected ¹³C NMR spectroscopy
    Kathleen Ennis
    Department of Pediatrics, Division of Neonatology, University of Minnesota, Mayo Mail Code 39, 420 Delaware Street, SE, Minneapolis, MN 55455, USA
    Neurochem Res 36:1962-8. 2011
    ..67 ± 0.13 μmol/g/min, a value comparable to previous ex vivo studies. This methodology opens the avenue for in vivo measurements of brain metabolic rates using ¹³C MRS in small animals...
  33. pmc Noninvasive quantification of human brain ascorbate concentration using 1H NMR spectroscopy at 7 T
    Melissa Terpstra
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA
    NMR Biomed 23:227-32. 2010
    ....
  34. pmc Neurochemical changes in Huntington R6/2 mouse striatum detected by in vivo 1H NMR spectroscopy
    Ivan Tkac
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA
    J Neurochem 100:1397-406. 2007
    ..Longitudinal monitoring of changes in these metabolites may provide quantifiable measures of disease progression and treatment effects in both mouse models of HD and patients...
  35. pmc Short-echo, single-shot, full-intensity proton magnetic resonance spectroscopy for neurochemical profiling at 4 T: validation in the cerebellum and brainstem
    GULIN OZ
    Center for MR Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 65:901-10. 2011
    ..A high correlation between metabolite concentrations obtained by these two proton (1) H MRS techniques indicated the sensitivity to detect intersubject variation in metabolite levels...
  36. ncbi request reprint Sensitivity of single-voxel 1H-MRS in investigating the metabolism of the activated human visual cortex at 7 T
    Silvia Mangia
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA
    Magn Reson Imaging 24:343-8. 2006
    ..Quantification of metabolites was, in general, not affected beyond 1% by line-width changes within 0.5 Hz...
  37. ncbi request reprint Brain glucose concentrations in poorly controlled diabetes mellitus as measured by high-field magnetic resonance spectroscopy
    Elizabeth R Seaquist
    Department of Medicine, University of Minnesota Medical School, MN 55455, USA
    Metabolism 54:1008-13. 2005
    ..1 micromol/g wet wt; P = .1). Our sample size gave 80% power to detect a difference as small as 1.1 micromol/g wet wt. We conclude that chronic hyperglycemia in diabetes does not alter brain glucose concentrations in human subjects...
  38. ncbi request reprint Brain glucose concentrations in patients with type 1 diabetes and hypoglycemia unawareness
    Amy B Criego
    Department of Pediatrics, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN 55455, USA
    J Neurosci Res 79:42-7. 2005
    ..5 +/- 0.3 vs. 4.7 +/- 0.1 micromol/g wet weight, P = 0.016). These data suggest that changes in brain glucose transport or metabolism may occur as a result of recurrent hypoglycemia...
  39. pmc Animal models and high field imaging and spectroscopy
    GULIN OZ
    Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
    Dialogues Clin Neurosci 15:263-78. 2013
    ..As a result, today, animal model studies are starting to be conducted at magnetic fields ranging from ~ 11 to 17 Tesla, significantly enhancing the armamentarium of tools available for the probing brain function and brain pathologies. ..