Joke Parthoens1, Stijn Servaes2, Jeroen Verhaeghe1, Sigrid Stroobants1,3, Steven Staelens4. 1. Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Antwerp, Belgium. 2. Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Antwerp, Belgium. stijn.servaes@uantwerpen.be. 3. Department of Nuclear Medicine, University Hospital Antwerp, Wilrijkstraat 10, 2650, Edegem, Antwerp, Belgium. 4. Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Antwerp, Belgium. steven.staelens@uantwerpen.be.
Abstract
PURPOSE: We evaluated the glucose metabolism after microinjections of a GABAA antagonist, bicuculline, and a GABAA agonist, muscimol, in the rat prelimbic cortex (PL) by small animal positron emission tomography (μPET). PROCEDURES: Following a microinjection of either 0.5 μl bicuculline (0.1 mg/ml), muscimol (1 mg/ml), or saline in the left PL of 11 healthy male Sprague Dawley rats (250-275 g), 2-deoxy-2-[(18)F]fluoro-β-D-glucose ([(18)F]FDG) PET images were acquired. Volume-of-interest (VOI)-based analysis and voxel-based statistical parametric mapping were performed (n = 9). RESULTS: VOI-based analysis revealed significantly different [(18)F]FDG uptake following bicuculline versus muscimol in PL (p < 0.001), infralimbic cortex (p < 0.01), and cingulate cortex (p < 0.01). Voxel-based analysis showed bicuculline induced widespread significant hypermetabolism throughout the brain while muscimol induced significant localized hypometabolism. CONCLUSIONS: Here, we visualize functional GABAA-mediated correlations of the PL following pharmacological stimulation. This could serve as a reference and shed light on the working and focality of other stimulation paradigms targeting this region.
PURPOSE: We evaluated the glucose metabolism after microinjections of a GABAA antagonist, bicuculline, and a GABAA agonist, muscimol, in the rat prelimbic cortex (PL) by small animal positron emission tomography (μPET). PROCEDURES: Following a microinjection of either 0.5 μl bicuculline (0.1 mg/ml), muscimol (1 mg/ml), or saline in the left PL of 11 healthy male Sprague Dawley rats (250-275 g), 2-deoxy-2-[(18)F]fluoro-β-D-glucose ([(18)F]FDG) PET images were acquired. Volume-of-interest (VOI)-based analysis and voxel-based statistical parametric mapping were performed (n = 9). RESULTS: VOI-based analysis revealed significantly different [(18)F]FDG uptake following bicuculline versus muscimol in PL (p < 0.001), infralimbic cortex (p < 0.01), and cingulate cortex (p < 0.01). Voxel-based analysis showed bicuculline induced widespread significant hypermetabolism throughout the brain while muscimol induced significant localized hypometabolism. CONCLUSIONS: Here, we visualize functional GABAA-mediated correlations of the PL following pharmacological stimulation. This could serve as a reference and shed light on the working and focality of other stimulation paradigms targeting this region.