Effects of alpha-lipoic acid in an animal model of mania induced by D-amphetamine

Deletion of histamine H2 receptor in VTA dopaminergic neurons of mice induces behavior reminiscent of mania

Hyperfunction of the dopamine system has been implicated in manic episodes in bipolar disorders. How dopaminergic neuronal function is regulated in the pathogenesis of mania remains unclear. Histaminergic neurons project dense efferents into the midbrain dopaminergic nuclei. Here, we present mice lacking dopaminergic histamine H2 receptor (H2R) in the ventral tegmental area (VTA) that exhibit a behavioral phenotype mirroring some of the symptoms of mania, including increased locomotor activity and reduced anxiety- and depression-like behavior. These behavioral deficits can be reversed by the mood stabilizers lithium and valproate. H2R deletion in dopaminergic neurons significantly enhances neuronal activity, concurrent with a decrease in the γ-aminobutyric acid (GABA) type A receptor (GABAAR) membrane presence and inhibitory transmission. Conversely, either overexpression of H2R in VTA dopaminergic neurons or treatment of H2R agonist amthamine within the VTA counteracts amphetamine-induced hyperactivity. Together, our results demonstrate the engagement of H2R in reducing VTA dopaminergic activity, shedding light on the role of H2R as a potential target for mania therapy.

Doxycycline reversal of amphetamine-induced mania-like behavior is related to adjusting brain monoamine abnormalities and antioxidant effects in primary hippocampal neurons

Mania is associated with disturbed dopaminergic transmission in frontotemporal regions. D-amphetamine (AMPH) causes increased extracellular DA levels, considered an acknowledged mania model in rodents. Doxycycline (DOXY) is a second-generation tetracycline with promising neuroprotective properties. Here, we tested the hypothesis that DOXY alone or combined with Lithium (Li) could reverse AMPH-induced mania-like behavioral alterations in mice by the modulation of monoamine levels in brain areas related to mood regulation, as well as cytoprotective and antioxidant effects in hippocampal neurons. Male Swiss mice received AMPH or saline intraperitoneal (IP) injections for 14 days. Between days 8-14, mice receive further IP doses of DOXY, Li, or their combination. For in vitro studies, we exposed hippocampal neurons to DOXY in the presence or absence of AMPH. DOXY alone or combined with Li reversed AMPH-induced risk-taking behavior and hyperlocomotion. DOXY also reversed AMPH-induced hippocampal and striatal hyperdopaminergia. In AMPH-exposed hippocampal neurons, DOXY alone and combined with Li presented cytoprotective and antioxidant effects, while DOXY+Li also increased the expression of phospho-Ser133-CREB. Our results add novel evidence for DOXY's ability to reverse mania-like features while revealing that antidopaminergic activity in some brain areas, such as the hippocampus and striatum, as well as hippocampal cytoprotective effects may account for this drug's antimanic action. This study provides additional rationale for designing clinical trials investigating its potential as a mood stabilizer agent.

Vitamin D3 and zinc supplements augment the antimanic efficacy of lithium and olanzapine treatments in an animal model of mania

Objective: Bipolar disorder (BD) is a challenging psychiatric disorder and a complex disease. The associated reduction in serum vitamin D3 (VitD3) levels in BD patients and the contribution of zinc (Zn) to the treatment, along with the severe side effects of lithium (Li) treatment, were encouraging to assess the efficacy of different correlated combinations of therapeutic/nutraceutical treatments such as olanzapine (Oln), VitD3, and Zn against Li. Methods: Mania was induced in C57BL/6 mice by administering methylphenidate (MPH) for 14 consecutive days. On the 8th day of MPH injection, different treatment regimens were administered, Li, Oln, VitD3/Zn, VitD3/Zn/Oln, VitD3 + Zn + Oln + Li50mg/kg (C50), and VitD3 + Zn + Oln + Li100mg/kg (C100). Both VitD3 (850 IU/kg) and Zn (180 mg/kg) were supplied with food for 2 weeks before starting the induction of mania, which continued until the end of MPH administration. Behavioral, brain oxidative stress, thyroid hormones, VitD3, Zn, GsK-3β, and Bcl2 levels, as well as brain histopathological alterations, were assessed. Results: Manic mice exhibited alterations in all tested parameters, and the histopathological examination of the cortex and hippocampus confirmed these results. The VitD3/Zn/Oln, C50, and C100 treatment regimens reversed most of the behavioral and pathophysiological alterations; however, the C50 treatment regimen was the most efficient. Conclusions: This study emphasizes the importance of combining different antimanic medications like Li and Oln with nutraceutical supplements to increase their antimanic efficacy, reduce their adverse effects, and, ideally, improve the BD patient's quality of life.

Pretreatment with Carpolobia lutea ethanol extract prevents schizophrenia-like behavior in mice models of psychosis

ETHNOPHARMACOLOGICAL RELEVANCE

Carpolobia lutea decoction is widely used as a phytotherapeutic against central nervous system-related disorders including insomnia, migraine headache, and mental illness in West and Central Tropical Africa.

AIM

This study was designed to investigate the antipsychotic activity of Carpolobia lutea (EECL) in mice models of psychosis.

METHODS

Male Swiss mice (n = 5/group) were given EECL (100, 200, 400, and 800 mg/kg), haloperidol (1 mg/kg), clozapine (5 mg/kg) and vehicle (10 mL/kg) orally before amphetamine (5 mg/kg)-induced hyperlocomotion and stereotypy, apomorphine (2 mg/kg)-induced stereotypy, or ketamine (10, 30, and 100 mg/kg)-induced hyperlocomotion, enhancement of immobility and cognitive impairment.

RESULTS

EECL (200, 400, and 800 mg/kg) prevented amphetamine- and apomorphine-induced stereotypies, as well as reduced hyperlocomotion induced by amphetamine and ketamine, all of which are predictors of positive symptoms. Regardless of the dose administered, EECL prevented the index of negative symptoms induced by ketamine. Furthermore, higher doses of EECL (400 and 800 mg/kg) also prevented ketamine-induced cognitive impairment, a behavioral phenotype of cognitive symptoms.

CONCLUSION

Pretreatment with EECL demonstrated antipsychotic activity in mice, preventing amphetamine-, apomorphine-, and ketamine-induced schizophrenia-like symptoms, with 800 mg/kg being the most effective dose.

Association of Polymorphism within the Putative miRNA Target Site in the 3'UTR Region of the DRD2 Gene with Neuroticism in Patients with Substance Use Disorder

The study aims at looking into associations between the polymorphism rs6276 that occurs in the putative miRNA target site in the 3'UTR region of the DRD2 gene in patients with substance use disorder (SUD) comorbid with a maniacal syndrome (SUD MANIA). In our study, we did not state any essential difference in DRD2 rs6276 genotype frequencies in the studied samples of SUD MANIA, SUD, and control subjects. A significant result was found for the SUD MANIA group vs. SUD vs. controls on the Neuroticism Scale of NEO FFI test, and DRD2 rs6276 (p = 0.0320) accounted for 1.7% of the variance. The G/G homozygous variants were linked with lower results on the neuroticism scale in the SUD MANIA group because G/G alleles may serve a protective role in the expression of neuroticism in patients with SUD MANIA. So far, there have been no data in the literature on the relationship between the miRSNP rs6276 region in the DRD2 gene and neuroticism (personal traits) in patients with a diagnosis of substance use disorder comorbid with the affective, maniacal type disturbances related to SUD. This is the first report on this topic.

Therapeutic approaches employing natural compounds and derivatives for treating bipolar disorder: emphasis on experimental models of the manic phase

Bipolar disorder (BD) is a complex psychiatric disease characterized by mood swings that include episodes of mania and depression. Given its cyclical nature, BD is especially hard to model; however, the standard practice has been to mimic manic episodes in animal models. Despite scientific advances, the pathophysiology of BD is not fully understood, and treatment remains limited. In the last years, natural products have emerged as potential neuroprotective agents for the treatment of psychiatric diseases. Thus, the aim of this review was to explore the therapeutic potential of natural compounds and derivatives against BD, taking into account preclinical and clinical studies. Reliable articles indexed in databases such as PubMed, Web of Science and Science Direct were used. In clinical studies, treatment with herbal plants extracts, omega-3, inositol, n-acetylcysteine and vitamin D has been associated with a clinical improvement in symptoms of mania and depression in BD patients. In animal models, it has been shown that red fruits extracts, curcumin, quercetin, gallic acid, alpha-lipoic acid and carvone can modulate many neurochemical pathways involved in the pathophysiology of manic episodes. Thus, this review appointed the advances in the consumption of natural compounds and derivatives as an important therapeutic strategy to mitigate the symptoms of BD.

The efficacy of alpha-lipoic acid in improving oxidative, inflammatory, and mood status in women with episodic migraine in a randomised, double-blind, placebo-controlled clinical trial

AIM

Migraine is a common neurovascular disorder, which is associated with severe to moderate disabling headaches. Oxidative stress and inflammation might play a role in migraine pathogenesis and the mood disorders. Considering the antioxidant and anti-inflammatory properties of alpha-lipoic acid (ALA), this study was designed to investigate its effect on oxidative, inflammatory, and mood conditions in women with episodic migraine.

METHODS

In total, 92 women with episodic migraine participated in the study. The patients were randomly divided into two groups, receiving a 300-mg capsule of ALA or placebo twice daily for 3 months. To assess the oxidative and inflammatory status, the serum levels of total antioxidant capacity (TAC), total oxidant status (TOS), glutathione (GSH), malondialdehyde (MDA), oxidative stress index (OSI), and C-reactive protein (CRP) were determined at the beginning and at the end of the intervention. A depression, anxiety, stress scale (DASS-21-items) questionnaire was used to evaluate mood status.

RESULTS

Finally, 79 patients reached the final analysis stage. At the end of the intervention, a significant decrease in the serum levels of MDA (means difference [MD]: -0.83, 95% confidence intervals (CI): -1.04, -0.62 nmol/mL vs MD: -0.32, CI: -0.48, -0.15 nmol/mL; P < .001) and CRP (MD: -0.78, CI: -1.17, -0.39 mg/L vs MD: -0.63, CI: -1.80, 0.52 mg/L; P < .001) was observed in the ALA as compared with the placebo group, but changes in serum GSH (P = .086), TAC (P = .068), TOS (P = .225), and OSI (P = .404) were not statistically significant. In addition, depression, anxiety, and stress (with P < .001, in all cases) had significantly decreased in the intervention as compared with the control group.

CONCLUSION

The results of this study suggest that ALA supplementation for 3 months has beneficial effects on improving the oxidative, inflammatory, and mood conditions of patients suffering from episodic migraine.

The Role of Mitochondria in Mood Disorders: From Physiology to Pathophysiology and to Treatment

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher levels of oxidative stress. Recently, many agents capable of enhancing antioxidant defenses or mitochondrial functioning have been studied for the treatment of mood disorders as adjuvant therapy to current pharmacological treatments. A better knowledge of mitochondrial physiology and pathophysiology might allow the identification of new therapeutic targets and the development and study of novel effective therapies to treat these specific mitochondrial impairments. This could be especially beneficial for treatment-resistant patients. In this article, we provide a focused narrative review of the currently available evidence supporting the involvement of mitochondrial dysfunction in mood disorders, the effects of current therapies on mitochondrial functions, and novel targeted therapies acting on mitochondrial pathways that might be useful for the treatment of mood disorders.

Doxycycline reverses cognitive impairment, neuroinflammation and oxidative imbalance induced by D-amphetamine mania model in mice: A promising drug repurposing for bipolar disorder treatment?

Immune-inflammatory mechanisms are involved in the pathophysiology of bipolar disorder. Tetracyclines present neuroprotective actions based on their anti-inflammatory and microglia suppressant effects. Doxycycline (DOXY) is a tetracycline that demonstrates a better usage profile with protective actions against inflammation and CNS injury. Here, we investigated the effects of DOXY against behavioral, neuroinflammatory, and pro-oxidative changes induced by the d-amphetamine mania model. Adult mice were given d-amphetamine 2.0 mg/kg or saline for 14 days. Between days 8 and 14, received lithium, DOXY (25 or 50 mg/kg), or their combination (lithium+DOXY) on both doses. We collected the brain areas prefrontal cortex (PFC), hippocampus, and amygdala to evaluate inflammatory and oxidative alterations. D-amphetamine induced hyperlocomotion and impairment in recognition and working memory. Lithium reversed hyperlocomotion but could not restore cognitive alterations. DOXY alone (at both doses) or combined with lithium reversed d-amphetamine-induced cognitive changes. DOXY, better than lithium, reversed the d-amphetamine-induced rise in TNFα, MPO, and lipid peroxidation. DOXY reduced the hippocampal expression of Iba1 (a marker of microglial activation), inducible nitric oxide synthase (iNOS), and nitrite. Combined with lithium, DOXY increased the phosphorylated (inactivated) form of GSK3β (Ser9). Therefore, DOXY alone or combined with lithium reversed cognitive impairment and neuroinflammation induced by the mice's d-amphetamine model. This study points to DOXY as a promising adjunctive tool for bipolar disorder treatment focused on cognition and neuroimmune changes. Our data provide the first rationale for clinical trials investigating DOXY therapeutic actions in bipolar disorder mania.

The effect of alpha lipoic acid on passive avoidance and social interaction memory, pain perception, and locomotor activity in REM sleep-deprived rats

BACKGROUND

Evidence shows the vital role of sleep in the modulation of cognitive functions. Sleep deprivation (SD) can disrupt learning and memory processes. SD also affects pain perception and locomotor activity. Furthermore, alpha lipoic acid (ALA) may induce antioxidant and neuroprotective effects. ALA affects memory processes, pain subthreshold, and locomotor activity. The goal of the present study was to investigate the effect of REM (rapid-eye movement) SD and ALA on social and passive avoidance memory, locomotor activity, and pain perception.

METHODS

Multiple-platform apparatus was used to induce REM SD for 24 h. Three-chamber paradigm test, the shuttle box, locomotion apparatus, and hot plate were used to assess social interaction memory, passive avoidance memory, locomotor activity, and pain perception, respectively. ALA was injected intraperitoneally at the doses of 35 and 70 mg/kg.

RESULTS

24 h REM SD impaired both types of memory. In addition, ALA (35 mg/kg) reversed REM SD-induced memory impairments. However, ALA (70 mg/kg) impaired social memory with no effect on REM SD-induced memory impairments. ALA (70 mg/kg) also decreased pain subthreshold in REM SD rats.

CONCLUSION

REM SD impairs social interaction and passive avoidance memory. Furthermore, ALA may exhibit a dose-dependent manner in some cognitive tasks. ALA can induce a therapeutic effect at one dose, and an impairment effect at another dose (lower or higher), while the cognitive task and the conditions are equal.

The GLP-1 receptor agonist liraglutide reverses mania-like alterations and memory deficits induced by D-amphetamine and augments lithium effects in mice: Relevance for bipolar disorder

Metabolic and psychiatric disorders present a bidirectional relationship. GLP-1 system, known for its insulinotropic effects, has also been associated with numerous regulatory effects in cognitive and emotional processing. GLP-1 receptors (GLP-1R) agonists present neuroprotective and antidepressant/anxiolytic properties. However, the effects of GLP-1R agonism in bipolar disorder (BD) mania and the related cognitive disturbances remains unknown. Here, we investigated the effects of the GLP-1R agonist liraglutide (LIRA) at monotherapy or combined with lithium (Li) against D-amphetamine (AMPH)-induced mania-like symptoms, brain oxidative and BDNF alterations in mice. Swiss mice received AMPH 2 mg/kg or saline for 14 days. Between days 8-14, they received LIRA 120 or 240 μg/kg, Li 47.5 mg/kg or the combination Li + LIRA, on both doses. After behavioral evaluation the brain areas prefrontal cortex (PFC), hippocampus and amygdala were collected. AMPH induced hyperlocomotion, risk-taking behavior and multiple cognitive deficits which resemble mania. LIRA reversed AMPH-induced hyperlocomotion, working and recognition memory impairments, while Li + LIRA240 rescued all behavioral changes induced by AMPH. LIRA reversed AMPH-induced hippocampal oxidative and neurotrophic changes. Li + LIRA240 augmented Li antioxidant effects and greatly reversed AMPH-induced BDNF changes in PFC and hippocampus. LIRA rescued the weight gain induced by Li in the course of mania model. Therefore, LIRA can reverse some mania-like behavioral alterations and combined with Li augmented the mood stabilizing and neuroprotective properties of Li. This study points to LIRA as a promising adjunctive tool for BD treatment and provides the first rationale for the design of clinical trials investigating its possible antimanic effect.

P2X7 Purinergic Receptor Is Involved in the Pathophysiology of Mania: a Preclinical Study

The pathophysiology of bipolar disorder remains incompletely elucidated. The purinergic receptor, P2X7 (P2X7R), plays a central role in neuroinflammation, the establishment, and maintenance of microglial activation and neuronal damage/death, all characteristics of bipolar disorder pathology. The present study aims to explore the participation of the P2X7R in a preclinical pharmacological model of mania. We analyzed the modulatory effects of the P2X7R antagonist, brilliant blue, on behavior, monoamines, gene expression, serum purine levels, and cell typing in a pharmacological model of mania induced by D-amphetamine (AMPH) in mice. Our results corroborate an association between the P2X7 receptor and the preclinical animal model of mania, as demonstrated by the decreased responsiveness to AMPH in animals with pharmacologically blocked P2X7R. This study further suggests a possible dopaminergic mechanism for the action of P2X7 receptor antagonism. Additionally, we observed increased peripheral levels of adenosine, a neuroprotective molecule, and increased central expression of Entpd3 and Entpd1 leading to the hydrolysis of ATP, a danger signal, possibly as an attempt to compensate for the damage induced by AMPH. Lastly, P2X7R antagonism in the AMPH model was found to potentially modulate astrogliosis. Our results support the hypothesis that P2X7R plays a vital role in the pathophysiology of mania, possibly by modulating the dopaminergic pathway and astrogliosis, as reflected in the behavioral changes observed. Taken together, this study suggests that a purinergic system imbalance is associated with the AMPH-induced preclinical animal model of mania. P2X7R may represent a promising molecular therapeutic target for bipolar disorder.

Ameliorating effect of postweaning exposure to antioxidant on disruption of hippocampal neurogenesis induced by developmental hypothyroidism in rats

Developmental hypothyroidism as a model of autism spectrum disorders disrupts hippocampal neurogenesis through the adult stage. The present study investigated the ameliorating effect of postweaning exposure to antioxidant on the hypothyroidism-induced disruptive neurogenesis. Mated female Sprague-Dawley rats were treated with 0 or 10 ppm 6-propyl-2-thiouracil (PTU) as an anti-thyroid agent in drinking water from gestational day 6 to postnatal day (PND) 21 on weaning. PTU-exposed male offspring were fed either basal diet, diet containing α-glycosyl isoquercitrin (AGIQ) at 5,000 ppm or α-lipoic acid (ALA) at 1,000 ppm as an antioxidant from PND 21 to PND 77. PTU-exposure decreased DCX⁺ and NeuN⁺ granule cell lineage subpopulations, synaptic plasticity-related FOS⁺ granule cells, and hilar PVALB⁺ and GAD67⁺ GABAergic interneurons, increased hilar SST⁺ and CALB2⁺ interneurons, and upregulated Gria3, Otx2, and antioxidant enzyme genes in the dentate gyrus on PND 77. These results suggest disruption of neurogenesis remained in relation with increase of oxidative stress and compensatory responses to the disruption at the adult stage. AGIQ recovered expression of some antioxidant enzyme genes and was effective for restoration of NeuN⁺ postmitotic granule cells and PVALB⁺ and SST⁺ interneurons. In contrast, ALA was effective for restoration of all interneuron subpopulations, as well as postmitotic granule cells, and upregulated Grin2a that may play a role for the restoration. Both antioxidants recovered expression of Otx2 and AGIQ-alone recovered Gria3, suggesting a reversal of disruptive neurogenesis by compensatory responses. Thus, postweaning antioxidant exposure may be effective for ameliorating developmental hypothyroidism-induced disruptive neurogenesis by restoring the function of regulatory system.

High Exploratory Phenotype Rats Exposed to Environmental Stressors Present Memory Deficits Accompanied by Immune-Inflammatory/Oxidative Alterations: Relevance to the Relationship Between Temperament and Mood Disorders

Low-exploratory (LE) and high-exploratory (HE) rodents mimic human depressive and hyperthymic temperaments, respectively. Mood disorders (MD) may be developed by the exposure of these temperaments to environmental stress (ES). Psychiatric symptoms severity in MD patients is related to the magnitude of memory impairment. Thus, we aimed at studying the consequences of the exposure of LE and HE male Wistar rats, during periadolescence, to a combination of ES, namely, paradoxical sleep deprivation (PSD) and unpredictable stress (US), on anxiety-related behavior in the plus maze test, working (WM) and declarative memory (DM) performance. We also evaluated hippocampal immune-inflammatory/oxidative, as consequences of ES, and prevention of ES-induced alterations by the mood-stabilizing drugs, lithium and valproate. Medium exploratory (ME) control rats were used for comparisons with HE- and LE-control rats. We observed that HE-controls presented increased anxiolytic behavior that was significantly increased by ES exposure, whereas LE-controls presented increased anxiety-like behavior relative to ME-controls. Lithium and valproate prevented anxiolytic alterations in HE+ES rats. HE+ES- and LE+ES-rats presented WM and DM deficits. Valproate and lithium prevented WM deficits in LE-PSD+US rats. Lithium prevented DM impairment in HE+ES-rats. Hippocampal levels of reduced glutathione (GSH) increased four-fold in HE+ES-rats, being prevented by valproate and lithium. All groups of LE+ES-rats presented increased levels of GSH in relation to controls. Increments in lipid peroxidation in LE+ES- and HE+ES-rats were prevented by valproate in HE+ES-rats and by both drugs in LE+ES-rats. Nitrite levels were increased in HE+ES- and LE+ES-rats (five-fold increase), which was prevented by both drugs in LE+ES-rats. HE+ES-rats presented a two-fold increase in the inducible nitric oxide synthase (iNOS) expression that was prevented by lithium. HE+ES-rats showed increased hippocampal and plasma levels of interleukin (IL)-1β and IL-4. Indoleamine 2, 3-dioxygenase 1 (IDO1) was increased in HE+ES- and LE+ES-rats, while tryptophan 2,3-dioxygenase (TDO2) was increased only in HE+ES-rats. Altogether, our results showed that LE- and HE-rats exposed to ES present distinct anxiety-related behavior and similar memory deficits. Furthermore, HE+ES-rats presented more brain and plasma inflammatory alterations that were partially prevented by the mood-stabilizing drugs. These alterations in HE+ES-rats may possibly be related to the development of mood symptoms.

Bipolar Disorder: Its Etiology and How to Model in Rodents

Characterized by the switch of manic and depressive phases, bipolar disorder was described as early as the fifth century BC. Nevertheless up to date, the underlying neurobiology is still largely unclear, assuming a multifactor genesis with both biological-genetic and psychosocial factors. Significant process has been achieved in recent years in researching the causes of bipolar disorder with modern molecular biological (e.g., genetic and epigenetic studies) and imaging techniques (e.g., positron emission tomography (PET) and functional magnetic resonance imaging (fMRI)). In this chapter we will first summarize our recent knowledge on the etiology of bipolar disorder. We then discuss how several factors observed to contribute to bipolar disorder in human patients can be manipulated to generate rodent models for bipolar disorder. Finally, we will give an overview on behavioral test that can be used to assess bipolar-disorder-like behavior in rodents.

Mitochondrial Agents for Bipolar Disorder

Background

Bipolar disorder is a chronic and often debilitating illness. Current treatment options (both pharmaco- and psychotherapy) have shown efficacy, but for many leave a shortfall in recovery. Advances in the understanding of the pathophysiology of bipolar disorder suggest that interventions that target mitochondrial dysfunction may provide a therapeutic benefit.

Methods

This review explores the current and growing theoretical rationale as well as existing preclinical and clinical data for those therapies aiming to target the mitochondrion in bipolar disorder. A Clinicaltrials.gov and ANZCTR search was conducted for complete and ongoing trials on mitochondrial agents used in psychiatric disorders. A PubMed search was also conducted for literature published between January 1981 and July 2017. Systematic reviews, randomized controlled trials, observational studies, case series, and animal studies with an emphasis on agents affecting mitochondrial function and its role in bipolar disorder were included. The search was augmented by manually searching the references of key papers and related literature. The results were presented as a narrative review.

Results

Mitochondrial agents offer new horizons in mood disorder treatment. While some negative effects have been reported, most compounds are overall well tolerated and have generally benign side-effect profiles.

Conclusions

The study of neuroinflammation, neurodegeneration, and mitochondrial function has contributed the understanding of bipolar disorder's pathophysiology. Agents targeting these pathways could be a potential therapeutic strategy. Future directions include identification of novel candidate mitochondrial modulators as well as rigorous and well-powered clinical trials.

Advantages of the Alpha-lipoic Acid Association with Chlorpromazine in a Model of Schizophrenia Induced by Ketamine in Rats: Behavioral and Oxidative Stress evidences

Schizophrenia is a chronic mental disorder reported to compromise about 1% of the world's population. Although its pathophysiological process is not completely elucidated, evidence showing the presence of an oxidative imbalance has been increasingly highlighted in the literature. Thus, the use of antioxidant substances may be of importance for schizophrenia treatment. The objective of this study was to evaluate the behavioral and oxidative alterations by the combination of chlorpromazine (CP) and alpha-lipoic acid (ALA), a potent antioxidant, in the ketamine (KET) model of schizophrenia in rats. Male Wistar rats (200-300 g) were treated for 10 days with saline, CP or ALA alone or in combination with CP previous to KET and the behavioral (open field, Y-maze and PPI tests) and oxidative tests were performed on the last day of treatment. The results showed that KET induced hyperlocomotion, impaired working memory and decreased PPI. CP alone or in combination with ALA prevented KET-induced behavioral effects. In addition, the administration of KET decreased GSH and increased nitrite, lipid peroxidation and myeloperoxidase activity. CP alone or combined with ALA prevented the oxidative alterations induced by KET. In conclusion, the treatment with KET in rats induced behavioral impairments accompanied by hippocampal oxidative alterations, possibly related to NMDA receptors hypofunction. Besides that, CP alone or combined with ALA prevented these effects, showing a beneficial activity as antipsychotic agents.

Antimanic activity of minocycline in a GBR12909-induced model of mania in mice: Possible role of antioxidant and neurotrophic mechanisms

BACKGROUND

Mania/hypomania is the cardinal feature of bipolar disorder. Recently, single administration of the dopamine transporter (DAT) inhibitor, GBR12909, was related to mania-like alterations. In the present study we aimed at testing behavioral and brain oxidant/neurotrophic alterations induced by the repeated administration of GBR12909 and its prevention/reversal by the mood stabilizing drugs, lithium (Li) and valproate (VAL) as well as by the neuroprotective drug, minocycline (Mino).

METHODS

Adult Swiss mice were submitted to 14 days protocols namely prevention and reversal. In the reversal protocol mice were given GBR12909 or saline and between days 8 and 14 received Li, VAL, Mino (25 or 50mg/kg) or saline. In the prevention treatment, mice were pretreated with Li, VAL, Mino or saline prior to GBR12909.

RESULTS

GBR12909 repeated administration induced hyperlocomotion and increased risk taking behavior that were prevented and reversed by the mood stabilizers and both doses of Mino. Li, VAL or Mino were more effective in the reversal of striatal GSH alterations induced by GBR12909. Regarding lipid peroxidation Mino was more effective in the prevention and reversal of lipid peroxidation in the hippocampus whereas Li and VAL prevented this alteration in the striatum and PFC. Li, VAL and Mino25 reversed the decrease in BDNF levels induced by GBR12909.

CONCLUSION

GBR12909 repeated administration resembles manic phenotype. Similarly to classical mood-stabilizing agents, Mino prevented and reversed GBR12909 manic-like behavior in mice. Thus, our data provide preclinical support to the design of trials investigating Mino's possible antimanic effects.

Animal models for bipolar disorder: from bedside to the cage

Bipolar disorder is characterized by recurrent manic and depressive episodes. Patients suffering from this disorder experience dramatic mood swings with a wide variety of typical behavioral facets, affecting overall activity, energy, sexual behavior, sense of self, self-esteem, circadian rhythm, cognition, and increased risk for suicide. Effective treatment options are limited and diagnosis can be complicated. To overcome these obstacles, a better understanding of the neurobiology underlying bipolar disorder is needed. Animal models can be useful tools in understanding brain mechanisms associated with certain behavior. The following review discusses several pathological aspects of humans suffering from bipolar disorder and compares these findings with insights obtained from several animal models mimicking diverse facets of its symptomatology. Various sections of the review concentrate on specific topics that are relevant in human patients, namely circadian rhythms, neurotransmitters, focusing on the dopaminergic system, stressful environment, and the immune system. We then explain how these areas have been manipulated to create animal models for the disorder. Even though several approaches have been conducted, there is still a lack of adequate animal models for bipolar disorder. Specifically, most animal models mimic only mania or depression and only a few include the cyclical nature of the human condition. Future studies could therefore focus on modeling both episodes in the same animal model to also have the possibility to investigate the switch from mania-like behavior to depressive-like behavior and vice versa. The use of viral tools and a focus on circadian rhythms and the immune system might make the creation of such animal models possible.

Electroencephalographic study of chlorpromazine alone or combined with alpha-lipoic acid in a model of schizophrenia induced by ketamine in rats

Schizophrenia is characterized by behavioral symptoms, brain function impairments and electroencephalographic (EEG) changes. Dysregulation of immune responses and oxidative imbalance underpins this mental disorder. The present study aimed to investigate the effects of the typical antipsychotic chlorpromazine (CP) alone or combined with the natural antioxidant alpha-lipoic acid (ALA) on changes in the hippocampal average spectral power induced by ketamine (KET). Three days after stereotactic implantation of electrodes, male Wistar rats were divided into groups treated for 10 days with saline (control) or KET (10 mg/kg, IP). CP (1 or 5 mg/kg, IP) alone or combined with ALA (100 mg/kg, P.O.) was administered 30 min before KET or saline. Hippocampal EEG recordings were taken on the 1st, 5th and 10th days of treatment immediately after the last drug administration. KET significantly increased average spectral power of delta and gamma-high bands on the 5th and 10th days of treatment when compared to control. Gamma low-band significantly increased on the 1st, 5th and 10th days when compared to control group. This effect of KET was prevented by CP alone or combined with ALA. Indeed, the combination of ALA 100 + CP1 potentiated the inhibitory effects of CP1 on gamma low-band oscillations. In conclusion, our results showed that KET presents excitatory and time-dependent effects on hippocampal EEG bands activity. KET excitatory effects on EEG were prevented by CP alone and in some situations potentiated by its combination with ALA.

Toxicity of the amphetamine metabolites 4-hydroxyamphetamine and 4-hydroxynorephedrine in human dopaminergic differentiated SH-SY5Y cells

Amphetamine (AMPH) is a psychostimulant used worldwide by millions of patients in the clinical treatment of attention deficit hyperactivity disorder, narcolepsy or even obesity, and is also a drug of abuse. 4-Hydroxynorephedrine (4-OHNE) and 4-hydroxyamphetamine (4-OHAMPH) are two major metabolites known to persist in the brain longer than AMPH. The contribution of AMPH metabolites for its neurotoxicity is undetermined. We evaluated the toxicity of AMPH and its metabolites 4-OHNE and 4-OHAMPH, obtained by chemical synthesis, in human dopaminergic differentiated SH-SY5Y neurons. Cells were exposed to AMPH (concentration range 0-5mM) or 4-OHAMPH or 4-OHNE (concentration range 0-10mM) for 24 or 48h, and the viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) leakage assays. Results showed that for both AMPH and the metabolites a concentration-dependent toxicity was observed. The toxic concentration 50% (TC₅₀) for AMPH and 4-OHNE following 24h exposure was circa 3.5mM and 8mM, respectively. For 4-OHAMPH the TC₅₀ was not reached in the tested concentration range. N-acetyl cysteine, cycloheximide, l-carnitine, and methylphenidate were able to reduce cell death induced by AMPH TC₅₀. Acridine orange/ethidium bromide staining showed evident signs of late apoptotic cells and necrotic cells following 24h exposure to AMPH 3.50mM. The 4-OHAMPH metabolite at 8.00mM originated few late apoptotic cells, whereas 4-OHNE at 8.00mM resulted in late apoptotic cells and necrotic cells, in a scenario similar to AMPH. In conclusion, the AMPH metabolite 4-OHNE is more toxic than 4-OHAMPH, nonetheless both are less toxic than the parent compound in vitro. The most toxic metabolite 4-OHNE has longer permanence in the brain, rendering likely its contribution for AMPH neurotoxicity.

Lipoic acid and haloperidol-induced vacuous chewing movements: Implications for prophylactic antioxidant use in tardive dyskinesia

Tardive dyskinesia (TD), a potentially irreversible antipsychotic (AP)-related movement disorder, is a risk with all currently available antipsychotics. AP-induced vacuous chewing movements (VCMs) in rats, a preclinical model of TD, can be attenuated by antioxidant-based treatments although there is a shortage of well-designed studies. Lipoic acid (LA) represents a candidate antioxidant for the treatment of oxidative stress-related nervous system disorders; accordingly, its effects on AP-induced VCMs and striatal oxidative stress were examined. Rats treated with haloperidol decanoate (HAL; 21mg/kg every 3weeks, IM) for 12weeks were concurrently treated with LA (10 or 20mg/kg, PO). VCMs were assessed weekly by a blinded rater, and locomotor activity was evaluated as were striatal lipid peroxidation markers and serum HAL levels. VCMs were decreased by the lower dose (nonsignificant), whereas a significant increase was recorded with the higher dose of LA. HAL decreased locomotor activity and this was unaffected by LA. Striatal malondialdehyde (MDA) levels in HAL-treated rats were reduced by both LA doses, while 4-hydroxynonenal (4-HNE) levels were predictive of final VCM scores (averaged across weeks 10-12). Study limitations include differences between antipsychotics in terms of oxidative stress, LA dosing, choice of biomarkers for lipid peroxidation, and generalizability to TD in humans. Collectively, current preclinical evidence does not support a "protective" role for antioxidants in preventing TD or its progression, although clinical evidence offers limited evidence supporting such an approach.

Quercetin reduces manic-like behavior and brain oxidative stress induced by paradoxical sleep deprivation in mice

Quercetin is a known antioxidant and protein kinase C (PKC) inhibitor. Previous studies have shown that mania involves oxidative stress and an increase in PKC activity. We hypothesized that quercetin affects manic symptoms. In the present study, manic-like behavior (hyperlocomotion) and oxidative stress were induced by 24h paradoxical sleep deprivation (PSD) in male Swiss mice. Both 10 and 40mg/kg quercetin prevented PSD-induced hyperlocomotion. Quercetin reversed the PSD-induced decrease in glutathione (GSH) levels in the prefrontal cortex (PFC) and striatum. Quercetin also reversed the PSD-induced increase in lipid peroxidation (LPO) in the PFC, hippocampus, and striatum. Pearson's correlation analysis revealed a negative correlation between locomotor activity and GSH in the PFC in sleep-deprived mice and a positive correlation between locomotor activity and LPO in the PFC and striatum in sleep-deprived mice. These results suggest that quercetin exerts an antimanic-like effect at doses that do not impair spontaneous locomotor activity, and the antioxidant action of quercetin might contribute to its antimanic-like effects.

Mitochondrial dysfunction in bipolar disorder: Evidence, pathophysiology and translational implications

Bipolar disorder (BD) is a chronic psychiatric illness characterized by severe and biphasic changes in mood. Several pathophysiological mechanisms have been hypothesized to underpin the neurobiology of BD, including the presence of mitochondrial dysfunction. A confluence of evidence points to an underlying dysfunction of mitochondria, including decreases in mitochondrial respiration, high-energy phosphates and pH; changes in mitochondrial morphology; increases in mitochondrial DNA polymorphisms; and downregulation of nuclear mRNA molecules and proteins involved in mitochondrial respiration. Mitochondria play a pivotal role in neuronal cell survival or death as regulators of both energy metabolism and cell survival and death pathways. Thus, in this review, we discuss the genetic and physiological components of mitochondria and the evidence for mitochondrial abnormalities in BD. The final part of this review discusses mitochondria as a potential target of therapeutic interventions in BD.

Modeling mania in preclinical settings: A comprehensive review

The current pathophysiological understanding of mechanisms leading to onset and progression of bipolar manic episodes remains limited. At the same time, available animal models for mania have limited face, construct, and predictive validities. Additionally, these models fail to encompass recent pathophysiological frameworks of bipolar disorder (BD), e.g. neuroprogression. Therefore, there is a need to search for novel preclinical models for mania that could comprehensively address these limitations. Herein we review the history, validity, and caveats of currently available animal models for mania. We also review new genetic models for mania, namely knockout mice for genes involved in neurotransmission, synapse formation, and intracellular signaling pathways. Furthermore, we review recent trends in preclinical models for mania that may aid in the comprehension of mechanisms underlying the neuroprogressive and recurring nature of BD. In conclusion, the validity of animal models for mania remains limited. Nevertheless, novel (e.g. genetic) animal models as well as adaptation of existing paradigms hold promise.

Evidence for protective effect of lipoic acid and desvenlafaxine on oxidative stress in a model depression in mice

Oxidative stress is implicated in the neurobiology of depression. Here we investigated oxidative alterations in brain areas of animals submitted to the model of depression induced by corticosterone (CORT) and the effects of the antioxidant compound alpha-lipoic acid (ALA) alone or associated with the antidepressant desvenlafaxine (DVS) in these alterations. Female mice received vehicle or CORT (20 mg/kg) during 14 days. From the 15th to 21st days different animals received further administrations of: vehicle, DVS (10 or 20 mg/kg), ALA (100 or 200 mg/kg), or the combinations of DVS10+ALA100, DVS20+ALA100, DVS10+ALA200, or DVS20+ALA200. Twenty-four hours after the last drug administration prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) were dissected for the determination of the activity of superoxide dismutase (SOD), reduced glutathione (GSH) and lipid peroxidation (LP) levels. CORT significantly increased SOD activity in the PFC and HC, decreased GSH levels in the HC and increased LP in all brain areas studied when compared to saline-treated animals. Decrements of SOD activity were observed in all groups and brain areas studied when compared to controls and CORT. The hippocampal decrease in GSH was reversed by ALA100, DVS10+ALA100, DVS20+ALA100 and DVS20+ALA200. The same DVS+ALA combination groups presented increased levels of GSH in the PFC and ST. The greater GSH levels were observed in the PFC, HC and ST of DVS20+ALA200 mice. LP was reversed in the groups ALA200 (PFC), DVS10+ALA100, DVS20+ALA100 (PFC, HC and ST), and DVS20+ALA200 (PFC, HC). Our findings contribute to the previous preclinical evidences implicating ALA as a promising agent for augmentation therapy in depression.

Reversal of corticosterone-induced BDNF alterations by the natural antioxidant alpha-lipoic acid alone and combined with desvenlafaxine: Emphasis on the neurotrophic hypothesis of depression

Brain derived neurotrophic factor (BDNF) is linked to the pathophysiology of depression. We hypothesized that BDNF is one of the neurobiological pathways related to the augmentation effect of alpha-lipoic acid (ALA) when associated with antidepressants. Female mice were administered vehicle or CORT 20mg/kg during 14 days. From the 15th to 21st days the animals were divided in groups that were further administered: vehicle, desvenlafaxine (DVS) 10 or 20mg/kg, ALA 100 or 200mg/kg or the combinations of DVS10+ALA100, DVS20+ALA100, DVS10+ALA200 or DVS20+ALA200. ALA or DVS alone or in combination reversed CORT-induced increase in immobility time in the forced swimming test and decrease in sucrose preference, presenting, thus, an antidepressant-like effect. DVS10 alone reversed CORT-induced decrease in BDNF in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST). The same was observed in the HC and ST of ALA200 treated animals. The combination of DVS and ALA200 reversed CORT-induced alterations in BDNF and even, in some cases, increased the levels of this neurotrophin when compared to vehicle-treated animals in HC and ST. Taken together, these results suggest that the combination of the DVS+ALA may be valuable for treating conditions in which BDNF levels are decreased, such as depression.

Antimanic-like activity of candesartan in mice: Possible involvement of antioxidant, anti-inflammatory and neurotrophic mechanisms

Activation of the brain angiotensin II type 1 receptor (AT1R) triggers pro-oxidant and pro-inflammatory mechanisms which are involved in the neurobiology of bipolar disorder (BD). Candesartan (CDS) is an AT1 receptor antagonist with potential neuroprotective properties. Herein we investigated CDS effects against oxidative, neurotrophic inflammatory and cognitive effects of amphetamine (AMPH)-induced mania. In the reversal protocol adult mice were given AMPH 2 mg/kg i.p. or saline and between days 8 and 14 received CDS 0.1, 0.3 or 1 mg/kg orally, lithium (Li) 47.5 mg/kg i.p., or saline. In the prevention treatment, mice were pretreated with CDS, Li or saline prior to AMPH. Locomotor activity and working memory performance were assessed. Glutathione (GSH), thiobarbituric acid-reactive substance (TBARS) and TNF-α levels were evaluated in the hippocampus (HC) and cerebellar vermis (CV). Brain-derived neurotrophic factor (BDNF) and glycogen synthase kinase 3-beta (GSK-3beta) levels were measured in the HC. CDS and Li prevented and reversed the AMPH-induced increases in locomotor activity. Only CDS prevented and reversed AMPH-induced working memory deficits. CDS prevented AMPH-induced alterations in GSH (HC and CV), TBARS (HC and CV), TNF-α (HC and CV) and BDNF (HC) levels. Li prevented alterations in BDNF and phospho-Ser9-GSK3beta. CDS reversed AMPH-induced alterations in GSH (HC and CV), TBARS (HC), TNF-α (CV) and BDNF levels. Li reversed AMPH-induced alterations in TNF-α (HC and CV) and BDNF (HC) levels. CDS is effective in reversing and preventing AMPH-induced behavioral and biochemical alterations, providing a rationale for the design of clinical trials investigating CDS׳s possible therapeutic effects.

GBR 12909 administration as an animal model of bipolar mania: time course of behavioral, brain oxidative alterations and effect of mood stabilizing drugs

Polymorphisms in the human dopamine transporter (DAT) are associated with bipolar endophenotype. Based on this, the acute inhibition of DAT using GBR12909 causes behavioral alterations that are prevented by valproate (VAL), being related to a mania-like model. Herein our first aim was to analyze behavioral and brain oxidative alterations during a 24 h period post-GBR12909 to better characterize this model. Our second aim was to determine the preventive effects of lithium (Li) or VAL 2 h post-GBR12909. For this, adult male mice received GBR12909 or saline being evaluated at 2, 4, 8, 12 or 24 h post-administration. Hyperlocomotion, levels of reduced glutathione (GSH) and lipid peroxidation in brain areas were assessed at all these time-points. GBR12909 caused hyperlocomotion at 2 and 24 h. Rearing behavior increased only at 2 h. GSH levels decreased in the hippocampus and striatum at the time points of 2, 4, 8 and 12 h. Increased lipid peroxidation was detected at the time-points of 2 and 12 h in all brain areas studied. At the time-point of 2 h post-GBR12909 Li prevented the hyperlocomotion and rearing alterations, while VAL prevented only rearing alterations. Both drugs prevented pro-oxidative changes. In conclusion, we observed that the main behavioral and oxidative alterations took place at the time-period of 2 h post-GBR12909, what points to this time-period as the best for the assessment of alterations in this model. Furthermore, the present study expands the predictive validity of the model by the determination of the preventive effects of Li.

Memory and brain-derived neurotrophic factor after subchronic or chronic amphetamine treatment in an animal model of mania

Progression of bipolar disorder (BD) has been associated with cognitive impairment and changes in neuroplasticity, including a decrease in serum brain-derived neurotrophic factor (BDNF). However, no study could examine BDNF levels directly in different brain regions after repeated mood episodes to date. The proposed animal model was designed to mimic several manic episodes and evaluate whether the performance in memory tasks and BDNF levels in hippocampus, prefrontal cortex, and amygdala would change after repeated amphetamine (AMPH) exposure. Adult male Wistar rats were divided into subchronic (AMPH for 7 days) and chronic groups (35 days), mimicking manic episodes at early and late stages of BD, respectively. After open field habituation or inhibitory avoidance test, rats were killed, brain regions were isolated, and BDNF mRNA and protein levels were measured by quantitative real-time PCR and ELISA, respectively. AMPH impaired habituation memory in both subchronic and chronic groups, and the impairment was worse in the chronic group. This was accompanied by increased Bdnf mRNA levels in the prefrontal cortex and amygdala region, as well as reduced BDNF protein in the hippocampus. In the inhibitory avoidance, AMPH significantly decreased the change from training to test when compared to saline. No difference was observed between subchronic and chronic groups, although chronically AMPH-treated rats presented increased Bdnf mRNA levels and decreased protein levels in hippocampus when compared to the subchronic group. Our results suggest that the cognitive impairment related to BD neuroprogression may be associated with BDNF alterations in hippocampus, prefrontal cortex, and amygdala.

Lipoic acid and pentoxifylline mitigate nandrolone decanoate-induced neurobehavioral perturbations in rats via re-balance of brain neurotransmitters, up-regulation of Nrf2/HO-1 pathway, and down-regulation of TNFR1 expression

Behavioral perturbations associated with nandrolone decanoate abuse by athletes and adolescents may be attributed to oxidative stress and inflammation. However, the underlying mechanisms are not yet fully explored. On the other hand, the natural antioxidant lipoic acid can pass the blood brain barrier and enhance Nrf2/HO-1 (nuclear factor erythroid-2 related factor 2/heme oxygenase-1) pathway. In addition, the phosphodiesterase-IV inhibitor xanthine derivative pentoxifylline has a remarkable inhibitory effect on tumor necrosis factor-alpha (TNF-α). Therefore, this study aimed at investigation of the possible protective effects of lipoic acid and/or pentoxifylline against nandrolone-induced neurobehavioral alterations in rats. Accordingly, male albino rats were randomly distributed into seven groups and treated with either vehicle, nandrolone (15mg/kg, every third day, s.c.), lipoic acid (100mg/kg/day, p.o.), pentoxifylline (200mg/kg/day, i.p.), or nandrolone with lipoic acid and/or pentoxifylline. Rats were challenged in the open field, rewarded T-maze, Morris water maze, and resident-intruder aggression behavioral tests. The present findings showed that nandrolone induced hyperlocomotion, anxiety, memory impairment, and aggression in rats. These behavioral abnormalities were accompanied by several biochemical changes, including altered levels of brain monoamines, GABA, and acetylcholine, enhanced levels of malondialdehyde and TNF-α, elevated activity of acetylcholinesterase, and up-regulated expression of TNF-α receptor-1 (TNFR1). In addition, inhibited catalase activity, down-regulated Nrf2/HO-1 pathway, and suppressed acetylcholine receptor expression were observed. Lipoic acid and pentoxifylline combination significantly mitigated all the previously mentioned deleterious effects mainly via up-regulation of Nrf2/HO-1 pathway, inhibition of TNF-α and down-regulation of TNFR1 expression. In conclusion, the biochemical and histopathological findings of this study revealed the protective mechanisms of lipoic acid and pentoxifylline against nandrolone-induced behavioral changes and neurotoxicity in rats.

Alpha-lipoic acid alone and combined with clozapine reverses schizophrenia-like symptoms induced by ketamine in mice: Participation of antioxidant, nitrergic and neurotrophic mechanisms

Oxidative stress has important implications in schizophrenia. Alpha-lipoic acid (ALA) is a natural antioxidant synthesized in human tissues with clinical uses. We studied the effect of ALA or clozapine (CLZ) alone or in combination in the reversal of schizophrenia-like alterations induced by ketamine (KET). Adult male mice received saline or KET for 14 days. From 8th to 14th days mice were additionally administered saline, ALA (100 mg/kg), CLZ 2.5 or 5 mg/kg or the combinations ALA+CLZ2.5 or ALA+CLZ5. Schizophrenia-like symptoms were evaluated by prepulse inhibition of the startle (PPI) and locomotor activity (positive-like), social preference (negative-like) and Y maze (cognitive-like). Oxidative alterations (reduced glutathione - GSH and lipid peroxidation - LP) and nitrite in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) and BDNF in the PFC were also determined. KET caused deficits in PPI, working memory, social interaction and hyperlocomotion. Decreased levels of GSH, nitrite (HC) and BDNF and increased LP were also observed in KET-treated mice. ALA and CLZ alone reversed KET-induced behavioral alterations. These drugs also reversed the decreases in GSH (HC) and BDNF and increase in LP (PFC, HC and ST). The combination ALA+CLZ2.5 reversed behavioral and some neurochemical parameters. However, ALA+CLZ5 caused motor impairment. Therefore, ALA presented an antipsychotic-like profile reversing KET-induced positive- and negative-like symptoms. The mechanism partially involves antioxidant, neurotrophic and nitrergic pathways. The combination of ALA+CLZ2.5 improved most of the parameters evaluated in this study without causing motor impairment demonstrating, thus, that possibly when combined with ALA a lower dose of CLZ is required.

Preclinical Evidences for an Antimanic Effect of Carvedilol

Oxidative imbalance, alterations in brain-derived neurotrophic factor (BDNF), and mitochondrial dysfunction are implicated in bipolar disorder (BD) pathophysiology and comorbidities, for example, cardiovascular conditions. Carvedilol (CVD), a nonselective beta-blocker widely used for the treatment of hypertension, presents antioxidant and mitochondrial stabilizing properties. Thus, we hypothesized that CVD would prevent and/or reverse mania-like behavioral and neurochemical alterations induced by lisdexamfetamine dimesylate (LDX). To do this, male Wistar rats were submitted to two different protocols, namely, prevention and reversal. In the prevention treatment the rats received daily oral administration (mg/kg) of CVD (2.5, 5 or 7.5), saline, valproate (VAL200), or the combination of CVD5 + VAL100 for 7 days. From the 8th to 14th day LDX was added. In the reversal protocol LDX was administered for 7 days with the drugs being added from the 8th to 14th day of treatment. Two hours after the last administration the behavioral (open field and social interaction) and neurochemical (reduced glutathione, lipid peroxidation, and BDNF) determinations were performed. The results showed that CVD prevented and reversed the behavioral and neurochemical alterations induced by LDX. The administration of CVD5 + VAL100 potentiated the effect of VAL200 alone. Taken together these results demonstrate a possible antimanic effect of CVD in this preclinical model.

The role of the GABA system in amphetamine-type stimulant use disorders

Abuse of amphetamine-type stimulants (ATS) has become a global public health problem. ATS causes severe neurotoxicity, which could lead to addiction and could induce psychotic disorders or cognitive dysfunctions. However, until now, there has been a lack of effective medicines for treating ATS-related problems. Findings from recent studies indicate that in addition to the traditional dopamine-ergic system, the GABA (gamma-aminobutyric acid)-ergic system plays an important role in ATS abuse. However, the exact mechanisms of the GABA-ergic system in amphetamine-type stimulant use disorders are not fully understood. This review discusses the role of the GABA-ergic system in ATS use disorders, including ATS induced psychotic disorders and cognitive dysfunctions. We conclude that the GABA-ergic system are importantly involved in the development of ATS use disorders through multiple pathways, and that therapies or medicines that target specific members of the GABA-ergic system may be novel effective interventions for the treatment of ATS use disorders.

Cerebroprotective effects of RAS inhibitors: Beyond their cardio-renal actions

Work on the brain renin-angiotensin system has been explored by various researchers and has led to elucidation of its basic physiologies and behavior, including its role in reabsorption and uptake of body fluid, blood pressure maintenance with angiotensin II being its prominent effector. Currently, this system has been implicated for its newly established effects, which are far beyond its cardio-renal effects accounting for maintenance of cerebral blood flow and cerebroprotection, seizure, in the etiology of Alzheimer's disease, Parkinson's disease, multiple sclerosis, and bipolar disorder. In this review, we have discussed the distribution of angiotensin receptor subtypes in the central nervous system (CNS) together with enzymatic pathways leading to active angiotensin ligands and its interaction with angiotensin receptor 2 (AT2) and Mas receptors. Secondly, the use of angiotensin analogues (angiotensin converting enzyme inhibitors and AT1 and/or AT2 receptor blockers) in the treatment and management of the CNS disorders mentioned above has been discussed.

Role of P2X7 Receptor in an Animal Model of Mania Induced by D-Amphetamine

The objective of this study was to explore the association between the P2X7 purinergic receptor (P2X7R) and neuroinflammation using a preclinical model of acute bipolar mania. We analyzed the modulatory effects of P2X7R agonist (3'-O-(4-benzoyl)benzoyl-adenosine 5'-triphosphate, BzATP) and antagonists (brilliant blue, BBG and 3-[[5-(2,3 dichlorophenyl)-1H-tetrazol-1-yl]methyl]pyridine hydrochloride, A438079) on assessments related to behavior (locomotor activity), neuroinflammation (interleukin-1 beta, IL-1β; tumor necrosis factor alpha, TNF-α; and interleukin- 6, IL-6), oxidative stress (thiobarbituric acid reactive substances, TBARS) and neuroplasticity (brain-derived neurotrophic factor, BDNF) markers in a pharmacological model of mania induced by acute and chronic treatment with D-amphetamine (AMPH) (2 mg/kg) in mice. An apparent lack of responsiveness to AMPH was observed in terms of the locomotor activity in animals with blocked P2X7R or with genetic deletion of P2X7R in knockout (P2X7R(-/-)) mice. Likewise, P2X7R participated in the AMPH-induced increase of the proinflammatory and excitotoxic environment, as demonstrated by the reversal of IL-1β, TNF-α, and TBARS levels caused by P2X7R blocking. Our results support the hypothesis that P2X7R plays a role in the neuroinflammation induced by AMPH in a preclinical model of mania, which could explain the altered behavior. The present data suggest that P2X7R may be a therapeutic target related to the neuroinflammation reported in bipolar disorder.

Effects of lithium on oxidative stress and behavioral alterations induced by lisdexamfetamine dimesylate: relevance as an animal model of mania

Lisdexamfetamine dimesylate (LDX) is a prodrug that requires conversion to d-amphetamine (d-AMPH) for bioactivity. Treatment with d-AMPH induces hyperlocomotion and is regarded as a putative animal model of bipolar mania. Therefore, we sought to determine the behavioral and oxidative stress alterations induced by sub-chronic LDX administration as well as their reversal and prevention by lithium in rats. A significant increment in locomotor behavior was induced by LDX (10 and 30 mg/kg). To determine Li effects against LDX-induced alterations, in the reversal protocol rats received LDX (10 or 30 mg/kg) or saline for 14 days. Between days 8 and 14 animals received Li (47.5 mg/kg, i.p.) or saline. In the prevention paradigm, rats were pretreated with Li or saline prior to LDX administration. Glutathione (GSH) levels and lipid peroxidation was determined in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) of rats. Lithium prevented LDX-induced hyperlocomotion at the doses of 10 and 30 mg/kg, but only reversed LDX-induced hyperlocomotion at dose of 10mg/kg. In addition, both doses of LDX decreased GSH content (in ST and PFC), while Li was able to reverse and prevent these alterations mainly in the PFC. LDX (10 and 30 mg/kg) increased lipid peroxidation which was reversed and prevented by Li. In conclusion, LDX-induced hyperlocomotion along with associated increments in oxidative stress show promise as an alternative animal model of mania.

Abstinence from repeated amphetamine treatment induces depressive-like behaviors and oxidative damage in rat brain

RATIONALE

Amphetamine has a significant potential for abuse and addiction. Among prolonged abusers, amphetamine withdrawal-induced depressive symptoms are common; however, their pathophysiological mechanism is not fully understood. Previously, we found that repeated treatment with amphetamine for 2 weeks induced oxidative stress in rat brain.

OBJECTIVES

The purpose of the current study is to analyze whether abstinence from repeated amphetamine treatment in rats induces depressive-like behaviors and if oxidative damage in the brain continues during abstinence.

METHODS

Rats were given repeated treatment with amphetamine once daily at 1, 2, or 4 mg/kg for 14 days. From 10 to 14 days after final amphetamine treatment, behavioral changes were monitored using open field test, novel object recognition test, and forced swim test. Oxidative damage in the medial frontal cortex and hippocampus was analyzed by immunohistochemistry.

RESULTS

We found that drug abstinence after repeated amphetamine stimulation decreased locomotor activity and exploratory behavior in the open field test, increased immobility in the forced swim test, and had no significant effect on the recognition index in the novel object recognition test. We also found that amphetamine abstinence increased levels of 4-hydroxynonenal-protein adducts and 8-hydroxyguanosine in rat medial frontal cortex and in CA3 and dentate gyrus regions of the hippocampus.

CONCLUSIONS

These results suggest that amphetamine abstinence displays depressive-like behaviors in rats and induces oxidative damage to lipids and RNA in rat brain. Our findings indicate that the process of oxidative stress may play a role in pathophysiological changes during drug abstinence from repeated amphetamine stimulation.