Concomitant use of carbamazepine and olanzapine and the effect on some behavioral functions in rats

Graded doses of grape seed methanol extract attenuated ataxic movement, cerebellocortical toxicity, and impairment following chronic carbamazepine treatment in male Wistar rats

This study investigated the effects of chronic cotreatment of carbamazepine (CBZ) with grape seed methanolic extract (GSME) on the markers of neurotoxicity and motor coordination in male rats. Thirty male Wistar rats were randomized into 5 groups (n = 6) and treated orally with propylene glycol (PG 0.1 ml/day), CBZ (25 mg/kg), CBZ (25 mg/kg) + GSME (200 mg/kg), CBZ (25 mg/kg) + GSME (100 mg/kg), or CBZ (25 mg/kg) + GSME (50 mg/kg) for 28 days. Thereafter, the animals were subjected to motor-coordination tests and, eventually, sacrificed by cervical dislocation. The cranium was opened and the brain excised. The prefrontal cortex (PFC) and cerebellum were homogenized for the biochemical assessment, while representative brain was fixed in 10% neutral-buffered formalin for the histomorphological investigation. The results were presented as mean ± SEM, analyzed using one-way analysis of variance (ANOVA) and Student-Newman-Keuls post hoc analysis where appropriate, while p < 0.05 was considered statistically significant. Indices of motor coordination were significantly (p = 0.0014) impaired with a significant (p = 0.0001) increase in the concentration of malondialdehyde (MDA) in the PFC and cerebellar tissue. In addition, the activities of glutathione increased (p = 0.0001) significantly in the CBZ + GSME-treated rats. All these anomalies were attenuated in the CBZ + GSME treated rats. Coadministration of GSME with CBZ may ameliorate CBZ-induced neurotoxicity, histoarchitectural disorganization of PFC and cerebellum with resultant effect on fine motor actions.

Effect of risperidone on the fluoxetine-induced changes in extracellular dopamine, serotonin and noradrenaline in the rat frontal cortex

BACKGROUND

Several clinical reports have documented a beneficial effect of the addition of a low dose of risperidone to the ongoing treatment with antidepressants, in particular selective serotonin reuptake inhibitors, in the treatment of drug resistant depression. The aim of our study was to understand the mechanism of the clinical efficacy of a combination of fluoxetine (FLU) and risperidone (RIS) in drug-resistant depression. We studied the effect of FLU and RIS, given separately or jointly on the extracellular levels of dopamine (DA), serotonin (5-HT) and noradrenaline (NA) in the rat frontal cortex.

METHODS

Animals were given single intraperitoneal injections of RIS at a doses of 0.1 or 1 mg/kg and FLU at a dose of 10 mg/kg. The release of DA, 5-HT and NA in the rat frontal cortex was investigated using microdialysis in freely moving animals. The extracellular level of DA, 5-HT and NA was assayed by HPLC with coulochemical detection.

RESULTS

RIS (0.1 and 1 mg/kg) and FLU (10 mg/kg) increased the extracellular level of cortical DA, 5-HT and NA. Co-treatment of both drugs was more effective in increasing DA release than administration of each of the drugs alone at doses of RIS 1 mg/kg and FLU 10 mg/kg. Co-treatment of FLU and RIS 0.1 mg/kg was more potent than FLU alone, while the effect of joint injection of FLU and RIS 1 mg/kg was stronger than RIS 1 mg/kg alone on 5-HT release. The combination of FLU with both doses of RIS was not effective in increasing NA release as compared to drugs given alone.

CONCLUSIONS

Our data indicate that the effect of the combined administration of RIS and FLU on DA and 5-HT release in the rat frontal cortex may be of crucial importance to the pharmacotherapy of drug resistant depression.

The influence of aripiprazole, olanzapine and enriched environment on depressant-like behavior, spatial memory dysfunction and hippocampal level of BDNF in prenatally stressed rats

BACKGROUND

Cognitive function deficits caused by impaired neurogenesis of the brain structures are considered an important pathogenic factor in many neurological and mental diseases such as schizophrenia and depression. The aim of the study was to determine the effect of the enriched environment on cognitive functions and antidepressant-like effect of prenatally stressed rats. It was important to determine the effect of aripiprazole ARI and olanzapine OLA and clarify whether the enriched environment induces increases in brain derived neurothropic factor BDNF in the hippocampus in the prenatally stressed group (PSG) and non-stressed control group (NSCG).

METHODS

The effect of chronic stress applied to pregnant rats and the use of ARI (1.5mg/kg ip) and OLA (0.5mg/kg ip) were studied in the Morris water maze (MWM), Porsolt Forced swimming test (FST) and by determining BDNF levels.

RESULTS

The results indicated that enriched environment improved spatial memory and also had an antidepressant-like effect on prenatally stressed rats. ARI improved spatial memory both in the NSCG and PSG, while OLA caused memory improvement only in the PSG. Moreover, both ARI and OLA reduced immobility time in the NSCG and PSG. In PSG rats, BDNF decrease was observed while chronic treatment with ARI and OLA increased BDNF levels in the hippocampi of NSCG and PSG rats.

CONCLUSION

It has been confirmed that enriched environment improves spatial memory of animals, removes symptoms of stress, has an antidepressant-like effect, and that new neuroleptics, such as ARI or OLA, modulate these functions (increased BDNF).