Positron emission tomography with fluorodeoxyglucose-F18 in an animal model of mania

Intracerebroventricular (ICV) administration of ouabain to young adult rats has been suggested to model human bipolar mania. In the human condition, mania and bipolar depression are both associated with reductions in frontal cerebral metabolism. We utilized [18F]-fluorodeoxyglucose [18FDG] positron emission tomography (PET) to visualize glucose uptake in animals receiving ICV ouabain. Animals received 5 µl of 10− 3 M ouabain ICV, were anesthetized with isoflurane inhalation, and administered intraperitoneally with 0.5 mCi of 18FDG. PET data were collected over 20 min 1 hour later. Additionally, the effect of lithium was examined in animals receiving lithium in their diet for 1 week before the ICV ouabain injection. Data were analyzed with IDL Virtual Machine software. Brain glucose utilization as measured by 18FDG uptake was significantly reduced in animals receiving ICV ouabain compared with those receiving equal volumes of artificial cerebrospinal fluid. Pretreatment with lithium normalized 18FDG uptake. These results mirror human studies.