Effects of fluoxetine on the rat brain in the forced swimming test: a [F-18]FDG micro-PET imaging study.
We used the [F-18]FDG micro-PET neuroimaging to examine the effects of fluoxetine on brain activity in rats and on their behavioral response in the forced swimming test (FST). In the first experiment, the rats were administered doses of fluoxetine (10 or 20mg/kg) 24, 19 and 1h before the rat brains were scanned. Fluoxetine induced strong activation of the dorsal hippocampus and the deactivation of the inferior colliculus, medulla oblongata, and prelimbic cortex in a dose-dependent manner. These results seemed to be related with the changes in 5-HT (5-hydroxytryptamine, serotonin) levels after selective serotonin reuptake-inhibitor treatments. In the second experiment, the changes in glucose metabolism in the test session were measured after fluoxetine was given between pre-test and test sessions of the FST. Fluoxetine administration significantly decreased immobility behavior compared with saline administration. At the same time, the activity of the insular/piriform cortex decreased significantly. In contrast, the extent of cerebellar activation increased. The glucose metabolism of the dorsal hippocampus also increased, which suggests that post-stress changes in the facilitation of hippocampal serotonergic neurotransmission lead to decreased immobilization in the FST.
Jang
Dong-Pyo
DP
Neuroscience Research Institute, Gachon University of Medicine and Science, 1198 Kuwol-dong, Namdong-gu, Incheon 405-760, Republic of Korea.
Lee
So-Hee
SH
Park
Chan-Woong
CW
Lee
Sang-Yoon
SY
Kim
Young-Bo
YB
Cho
Zang-Hee
ZH
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D001931:Brain Mapping; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D003866:Depressive Disorder / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D019788:Fluorodeoxyglucose F18; D005473:Fluoxetine / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D013315:Stress, Psychological / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D013550:Swimming / Q000523:psychology
D019788:Fluorodeoxyglucose F18; D005473:Fluoxetine; D005947:Glucose; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors