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Arterial spin labeling demonstrates that focal amygdalar glutamatergic agonist infusion leads to rapid diffuse cerebral activation |
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| Authors: | J. P. Munasinghe M. Banerjee M. T. Acosta M. Banks A. Heffer A. C. Silva A. Koretsky W. H. Theodore |
| Affiliation: | 1. MRI Research Facility;2. Epilepsy Research Section;3. Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke;4. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA |
| Abstract: | Munasinghe JP, Banerjee M, Acosta MT, Banks M, Heffer A, Silva AC, Koretsky A, Theodore WH. Arterial spin labeling demonstrates that focal amygdalar glutamatergic agonist infusion leads to rapid diffuse cerebral activation. Acta Neurol Scand: 2010: 121: 209–216. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives – To investigate acute effects of intra‐amygdalar excitatory amino acid administration on blood flow, relaxation time and apparent diffusion coefficient in rat brain. Materials and methods – Several days after MR‐compatible cannula placement in right basolateral amygdala, anesthetized rats were imaged at 7 T. Relative cerebral blood flow (CBF) was measured before and 60 min after infusion of 10 nmol KA, cAMPA, ATPA, or normal saline using arterial spin labeling. Quantitative T2 and diffusion‐weighted images were acquired. rCBF, T2 and ADC values were evaluated in bilateral basolateral amygdala, hippocampus, basal ganglia, frontal and parietal regions. Results – KA led to the highest, and ATPA lowest bilateral rCBF increases. Time courses varied among drugs. T2 for KA and AMPA was higher while ADC was lower for KA. Conclusions – Intra‐amygdalar injection of GluR agonists evoked bilateral seizure activity and increased rCBF, greater for KA and AMPA than selective ATPA GluR5 activation. |
| Keywords: | glutamate receptors KA ATPA AMPA MRI CBF seizures |