[Depression-like changes in behavior and c-fos gene expression in dopaminergic brain structures in WAG/Rij rats].
In WAG/Rij rats with genetic absence epilepsy, inborn changes in behavior were observed such as decreased level of locomotion, exploratory activity, and grooming reactions in the open-field test, increased immobility in the forced-swimming test, and decreased sucrose consumption (anhedonia) as compared to Wistar rats completely lacking in seizure pathology. These behavioral alterations in WAG/Rij rats resemble the symptoms of human depression (psychomotor retardation, depressed mood, and anhedonia). No significant behavioral changes were found in the light-dark choice, social interaction, and elevated plus-maze tests. This suggests the absence of increased anxiety in WAG/Rij rats. In contrast to Wistar, WAG/Rij rats were sensitive only to chronic treatment with antidepressant imipramine like depressive patients. Behavioral "despair" induced by forced swimming led to C-fos gene expression in three brain structures (frontal cortex, nucleus accumbens, and striatum), which are, respectively, terminal regions of three dopaminergic brain systems (mesocortical, mesolimbc, and nigrostriatal). c-fos gene expression in the brain of WAG/Rij rats was substantially different from that in the brain of Wistar rats in both intensity (in WAG/Rij the c-fos gene expression was higher than in Wistar rats in all involved brain structures) and its distribution between the structures. The results suggest that WAG/Rij strain is a new experimental (genetic) model of absence epilepsy-related depression unassociated with increased anxiety.
Sarkisova
K Iu
KIu
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow.
Midzianovskaia
I S
IS
Kulikov
M A
MA
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D003863:Depression / Q000150:complications / Q000188:drug therapy / Q000235:genetics* / Q000523:psychology*; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D004832:Epilepsy, Absence / Q000150:complications / Q000503:physiopathology; D005786:Gene Expression Regulation / Q000187:drug effects; D016762:Genes, fos; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D013395:Sucrose / Q000494:pharmacology; D013550:Swimming
D000928:Antidepressive Agents; D013395:Sucrose; D007099:Imipramine; D004298:Dopamine