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

Abstract

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 T(2) and diffusion-weighted images were acquired. rCBF, T(2) 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. T(2) 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.

• Authors: J P Munasinghe, M Banerjee, M T Acosta, M Banks, A Heffer, A C Silva, A Koretsky, W H Theodore
• Journal: Acta neurologica Scandinavica (Acta Neurol Scand) Vol. 121 Issue 3 Pg. 209-16 (Mar 2010) ISSN: 1600-0404 [Electronic] Denmark
• PMID: 19951270 (Publication Type: Journal Article)

Chemical References

• Excitatory Amino Acid Agonists

Topics

• Amygdala (blood supply, drug effects)
• Animals
• Arteries (drug effects)
• Blood Pressure (drug effects)
• Brain Mapping
• Cerebrovascular Circulation (drug effects)
• Diffusion Magnetic Resonance Imaging (methods)
• Disease Models, Animal
• Electroencephalography
• Excitatory Amino Acid Agonists (pharmacology)
• Functional Laterality (drug effects, physiology)
• Image Processing, Computer-Assisted (methods)
• Male
• Rats