Objective: Neuroimaging studies of depression considered as a stress-related disorder have shown uncoupling in regional cerebral blood flow (rCBF) and regional cerebral metabolic rate for glucose (rCMRglc). We hypothesised that the mismatch change of rCBF and rCMRglc could be a stress-related phenomenon.
Methods: We exposed male rats to 15-min period of forced swim (FS), followed by the measurement of rCBF using N-isopropyl-4-[123I] iodoamphetamine (123I-IMP) and rCMRglc using 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG).
Results: The uptake rate of 18F-FDG in the FS group showed a significant decrease in the prefrontal cortex (0.86±0.20%ID/g, p<0.01) and thalamus (0.77±0.17%ID/g, p<0.05) and tended to be lower in the hippocampus (0.58±0.13%ID/g) and cerebellum (0.59±0.13%ID/g) without overt alteration in the uptake rate of 123I-IMP.
Conclusions: The FS stress can cause mismatch change of rCBF and rCMRglc, which reflect a stress-related phenomenon.
Keywords: depression; forced swim stress; rat; regional cerebral blood flow; regional cerebral metabolic rate for glucose.