[Neurochemical mechanisms of depression-like behavior in WAG/Rij rats].

Behavior in the light-dark choice, open-field, sucrose consumption/preference and forced swimming tests, monoamines and their metabolites level in 6 brain structures (prefrontal cortex, nucleus accumbens, striatum, hypothalamus, hippocampus, amygdala), and density of D2-like dopamine receptors in 21 brain regions were studied in WAG/Rij and Wistar rats. WAG/Rij rats exhibited symptoms of depression-like behavior such as increased immobility in the forced swim test and decreased sucrose consumption/preference (anhedonia). Substantial changes in behavior indicating increased anxiety in WAG/Rij rats were not revealed.

[Does antiabsence drug ethosuximide exert antidepressant effect?].

Antiabsence drug ethosuximide (300 mg/kg/day in drinking water for 17 days) produced an antidepressant effect (a decrease in immobility time in forced swimming test) only in WAG/Rij rats genetically predisposed to absence epilepsy only at age of 5 months when spike-wave discharges well pronounced. On rats without spike-wave discharges (21-day-old WAG/Rij and Wistar rats at the age of both at 21 day and 5 months), ethosuximide didn't produce the antidepressant effect but tended to increases the immobility time and significantly decreases the number of divings (active behavior oriented to escape from stressful situation). Ethosuximide didn't substantially change the anxiety level in WAG/Rij rats but significantly enhanced anxiety in 21-day-old Wistar rats.

[Effect of selective serotonin reuptake inhibitor fluoxetine on symptoms of depression-like behavior in WAG/Rij rats].

A possibility to correct behavioral symptoms of depression-like behasior in WAG/Rij rats with selective serotonin reuptake inhibitor antidepressant drug fluoxetine was studied. The efficacy of fluoxetine was compared with that of tricyclic antidepressant imipramine. Vehicle-treated WAG/Rij rats compared with the corresponding group of Wistar rats exhibited symptoms of depression-like behavior: a decreased level of exploratory activity and grooming reactions in the open field test, increased immobility in the forced swimming test, and decreased sucrose intake and preference (anhedonia).

Dopamine-dependent nature of depression-like behavior in WAG/Rij rats with genetic absence epilepsy.

WAG/Rij rats given placebo showed a depression-like state as compared with normal Wistar rats (lacking convulsive pathology); this was analogous to the state previously seen in rats of this line, with decreased investigative activity in the open field test, increased immobility in the forced swimming test, and decreased consumption and preference for sucrose solution (anhedonia). Chronic administration of the tricyclic antidepressant imipramine (15 mg/kg, i.p.

[Dopamine-dependent character of depressive-like behavior in WAG/Rij rats with genetic absence epilepsy].

Placebo-treated WAG/Rij rats (as compared to normal Wistar rats without seizure pathology) exhibited depressive-like behavior similar to that of intact rats of the same strain: decreased exploratory activity in the open field test, increased immobility in the forced swimming test, decreased sucrose consumption and preference (anhedonia). Chronic injection of tricyclic antidepressant imipramine (15 mg/kg. i.