TRADITIONAL POSTER - ismrm

Poster Sessions
2401. Increased Brain Lactate Transport and Metabolism During Hypoglycemia in Rats Fed a Ketogenic
Diet
Henk M. De Feyter 1 , Kevin Behar 1 , Lester R. Drewes 2 , Robin A. de Graaf 1 , Douglas L. Rothman 1
1 Diagnostic Radiology, Yale University, New Haven, CT, United States; 2 Biochemistry & Molecular Biology, University of
Minnesota, Duluth, MN, United States
Repetitive iatrogenic hypoglycemic events lead to brain adaptations resulting in failing counterregulatory response and lack of warning symptoms
(hypoglycemia unawareness) normally associated with low blood glucose levels. Increased blood-brain barrier lactate transport via upregulated
monocarboxylic acid transporter 1 (MCT1) has been suggested as an adaptation induced by repetitive hypoglycemia. Increased lactate uptake and oxidation
could (partially) replace glucose thereby contribute to hypoglycemia unawareness and failing counterregulatory response. We used 1 H-[ 13 C] MRS combined
with [3- 13 C]-lactate infusion during hypoglycemia to investigate the role of increased lactate transport and/or metabolism in the brain of a rat model with
ketogenic diet-induced upregulation of MCT1.
2402. Acute Flupirtine Administration Reduces Glutamate/glutamine Ratio in Rat Hippocampus
Renuka Sriram 1 , Robert J. Mather 2 , Serguei Liachenko 1
1 BioImaging CoE, Pfizer Inc, Groton, CT, United States; 2 Neuroscience, Pfizer Inc, Groton, CT, United States
Neurotransmitter levels of glutamate and glutamine are tightly coupled with modulation of one resulting in a corresponding opposing change in the other.
Since glutamate is implicated in a variety of neurological disorders, the observation of an endogenous pool of glutamate (Glu) and glutamine (Gln) and/or its
ratio can serve as a strong mechanistic biomarker and measure of efficacy. Flupirtine, a potassium channel opener, has been shown to cause decrease in Glu
and a relative increase in Gln in the rat hippocampus.
2403. 1H MRS Profiling at 9.4T in Prefrontal Cortex and Hippocampus of Ethanol Dependent Rats During
Intoxication, Withdrawal and Protracted Abstinence
Wolfgang Weber-Fahr 1 , Gabriele Ende 1 , Alexander Sartorius 1 , Rainer Spanagel 2 , Claudia Falfan-
Melgoza 1 , Dirk Cleppien 1 , Wolfgang H. Sommer 2
1 Neuroimaging, Central Institute of Mental Health, Mannheim, NA, Germany; 2 Dept. Psychopharmacology, Central Institute of
Mental Health, Mannheim, NA, Germany
Out of a group of 17 animals eight were made dependent by 7 weeks ethanol vapor exposure with peak levels up to 4 g/l blood alcohol concentration. We
assessed metabolic profiles in two brain regions with functional importance for dependence, i.e. medial prefrontal cortex and hippocampus, using in vivo
single-voxel 1H magnetic resonance spectroscopy at TE=10 ms on a 9.4T scanner. Animals were measured up to 5 times before during and after ethanol
exposure. Reduced myoinositol and N-acetylaspartate levels as well as increased choline-containing compounds were found during intoxication. Raised
glutamate levels were found during early withdrawal.
2404. Brain Neurochemical Effects of Long-Term Sleep Fragmentation Investigated in Mice at 14.1T Using
1H-MRS
Nathalie Just 1,2 , Maxime Baud 3 , Jean-Marie Petit 3 , Pierre Magistretti 3,4 , Rolf Gruetter 1,5
1 LIFMET, CIBM, EPFL, Lausanne, Switzerland; 2 Department of Radiology, UNIL, Lausanne, Switzerland; 3 Laboratoire de
neuroénergétique et dynamique cellulaire, EPFL, Lausanne, Switzerland; 4 Brain and Mind Institute, Lausanne, Switzerland;
5 Department of Radiology, UNIL and HUG, Lausanne and Geneva, Switzerland
The present study examined the effects of sleep fragmentation (SF) in the hippocampus and the cortex of mice using proton MR spectroscopy at 14.1T.
Disruptions in brain sensory processing and cognitive performance were seen during sleep fragmentation. Moreover, there is evidence that SF negatively
affects memory and learning. Here, significant decreases in GABA and Lactate concentrations were detected in the hippocampus of mice following sleep
fragmentation indicating decreased synaptic function in the hippocampus.
2405. Regional Variations of Metabolite Concentrations in the Rat Brain Assessed with in Vivo 1 H MR
Spectroscopy at 16.4T
Sung-Tak Hong 1 , Dávid Zsolt Balla 1 , Gunamony Shajan 1 , Changho Choi 2 , Rolf Pohmann 1
1 High-Field Magnetic Resonance Center , Max-Planck Institute for Biological Cybernetics, Tuebingen, Baden-Wuerttemberg,
Germany; 2 Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
Regional differences of metabolites in the rat brain were investigated by using localized in vivo 1H MR spectroscopy at 16.4T. Three regions, thalamus,
striatum and hippocampus, were investigated with an ultra-short TE STEAM sequence. The results demonstrated significant variations in all metabolites
except aspartate and NAA. The remarkable variation of spectra was the substantially decreased level of the Tau methylene signal at 3.25 ppm in thalamus.
The significant increase of the GABA methylene signal at 1.89 ppm was also observed in thalamus.
2406. Measurement of the Effects of Different Anesthetics in the Rat Thalamus by in Vivo 1 H NMR
Spectroscopy at 16.4T
Sung-Tak Hong 1 , Chi-Bong Choi 2 , Rolf Pohmann 1
1 High-Field Magnetic Resonance Center , Max-Planck Institute for Biological Cybernetics, Tuebingen, Baden-Wuerttemberg,
Germany; 2 Department of Radiology, Kyung Hee University Medical Center, Hoekidong, Seoul, Korea, Republic of
The effect of different anesthetic agents was investigated in the rat brain by using in vivo 1H NMR spectroscopy. A volume-of-interest was placed in
thalamus under two different anesthesia, isoflurane and ketamine/xylazine. The significant increase of glucose was observed in a deep ketamine/xylazine
anesthesia while additional metabolic variations on ascorbate, aspartate, glutathione and lactate were detected.