Arterial spin labeling demonstrates that focal amygdalar glutamatergic agonist infusion leads to rapid diffuse cerebral activation

Authors


W. H. Theodore, National Institute for Neurological Disorders and Stroke/National Institutes of Health, Building 10 Room 5N-250, Bethesda, MD 20892, USA
Tel.: +1 301 402 1505
Fax: +1 301 402 2871
e-mail: theodorw@ninds.nih.gov

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.

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