Characterisation of peripheral benzodiazepine receptors changes in early phase of epileptogenesis in the rat with PET and [18F]PBR111
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Date
2009-05
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Nuclear Medicine
Abstract
The current project aims at investigating the role of microglial activation in epileptogenesis by estimating PBR changes in the rat brain with a new and highly specific PBR ligand, [18F]PBR111, during the early phase, i.e. one week after status epilepticus induced by kainic acid (KA). Methods Four controls and 6 KA rats were scanned for 180 minutes with our small animal PET/CT under a triple-injection protocol. The results presented here cover only the first 60 minutes after injection of 0.06nmoles of [18F]PBR111. Arterial blood samples were withdrawn and metabolite corrected plasma time-activity curves were derived. Each CT and PET data were co-registered to an age and strain matched rat brain atlas containing 25 Regions-Of-Interest (ROIs). The Volume of Distribution (Vd) were calculated for each region. Whole-brain-normalised Vd (nVd) were also calculated to assess local variations. Results Compared to controls, KA-treated rats show a 2 to 3-fold increase of the Vd in all brain areas except the midbrain. No significant asymmetry was detected (< 9%), so the ROIs were grouped. Normalized Vd values (Table 1) show that Amygdala, Striata, Thalamus and Hippocampus are predominantly involved. No significant changes were detected in the midbrain and all cortical areas. Estimates of receptors densitiy (Bmax) and apparent affinity (KdVr) will be calculated from the full kinetics (three phases) and reported later. Conclusions This in vivo imaging study has identified significant microglial activation during early epileptogenesis in several brain regions which are known to play a key role in chronic epilepsy.
Description
Citation shows author as C. Loch. The correct spelling is Loc'h.
Keywords
Positron computed tomography, Receptors, Rats, Brain, CAT scanning, Injection, Metabolites, Blood plasma
Citation
Gregoire, M.-C., Dedeurwaerdere, S., Callaghan, P., Loch, C., Pham, T., & Katsifis, A. (2009). Characterisation of peripheral benzodiazepine receptors changes in early phase of epileptogenesis in the rat with PET and [18F]PBR111. Paper presented to the Society of Nuclear Medicine Annual Meeting, Toronto Metro Convention Center, Canada, 13-17 June, 2009. In Journal of Nuclear Medicine, 50(supplement 2), 550. Retrieved from http://jnm.snmjournals.org/content/50/supplement_2/550.abstract