Changes in cerebral [F]-FDG uptake induced by acute alcohol administration in a rat model of alcoholism.

Several [F]-FDG positron emission tomography (PET) studies in alcoholics have consistently reported decreases in overall brain glucose metabolism at rest and following acute alcohol administration. However, changes in cerebral glucose utilization associated with the transition to addiction are not well understood and require longitudinal translational imaging studies in animal models of alcoholism. Here, we studied brain glucose uptake in alcohol drinking rats in order to provide convergent evidence to what has previously been reported in human studies.

[(11)C]-DASB microPET imaging in the aged rat: frontal and meso-thalamic increases in serotonin transporter binding.

Whereas molecular imaging studies in the aging human brain have predominantly demonstrated reductions in serotonin transporter (5-HTT) availability, the majority of the rodent studies, using autoradiographic methods, report increases in neural 5-HTT levels with age. To our knowledge, however, no previous rodent studies have assessed this topic in vivo, and therefore it remains unclear whether this discrepancy arises from methodological or inter-species differences. We performed an [(11)C]-DASB microPET study to evaluate the effects of aging on 5-HTT availability in the rat brain.

In vivo molecular imaging of the GABA/benzodiazepine receptor complex in the aged rat brain.

The GABA-ergic system, known to regulate neural tissue genesis during cortical development, has been postulated to play a role in cerebral aging processes. Using in vivo molecular imaging and voxel-wise quantification, we aimed to assess the effects of aging on the benzodiazepine (BDZ) recognition site of the GABA(A) receptor. To visualize BDZ site availability, [(11)C]-flumazenil microPET acquisitions were conducted in young and old rats.

Simultaneous dual-tracer PET imaging of the rat brain and its application in the study of cerebral ischemia.

Purpose: This study evaluates the performance of simultaneous dual-tracer technique (SDTT) in static positron emission tomography (PET) studies using 2-deoxy-2-[¹⁸F]fluoro-D-glucose and [¹³N]ammonium as radiotracers.

Procedures: The effects of applying SDTT either to the reconstructed image or directly to the sinogram, different rebinning algorithms, total acquisition time, and frame duration were investigated; first, using a specific phantom and later using an in vivo application of the study of cerebral ischemia.

Results: The best results were obtained using the image method with single-slice rebinning and a total acquisition time of at least 20 min.

Evaluation of hypoxic tissue dynamics with 18F-FMISO PET in a rat model of permanent cerebral ischemia.

Purpose: [¹⁸F]Fluoromisonidazole (¹⁸F-FMISO) is a nitroimidazole derivative that has been proposed as a positron emission tomography (PET) radiotracer to detect hypoxic tissue in vivo. This compound accumulates in hypoxic but viable tissue and may be a good candidate for evaluating the ischemic penumbra. We evaluated the time course of ¹⁸F-FMISO uptake using PET in a rat model of permanent cerebral ischemia and the correlation with histological changes.