Bipolar disorder (BD) is a chronic mental illness characterized by changes in mood that alternate between mania and hypomania or between depression and mixed states, often associated with functional impairment. Although effective pharmacological and non-pharmacological treatments are available, several patients with BD remain symptomatic. The advance in the understanding of the neurobiology underlying BD could help in the identification of new therapeutic targets as well as biomarkers for early detection, prognosis, and response to treatment in BD. In this review, we discuss genetic, epigenetic, molecular, physiological and neuroimaging findings associated with the neurobiology of BD. Despite the advances in the pathophysiological knowledge of BD, the diagnosis and management of the disease are still essentially clinical. Given the complexity of the brain and the close relationship between environmental exposure and brain function, initiatives that incorporate genetic, epigenetic, molecular, physiological, clinical, environmental data, and brain imaging are necessary to produce information that can be translated into prevention and better outcomes for patients with BD.

O femproporex é o segundo anorexígeno à base de anfetamina mais consumido no mundo; esse fármaco é rapidamente convertido in vivo em anfetamina e atua através do aumento dos níveis de dopamina na fenda sináptica. Considerando que os efeitos do femproporex sobre o Sistema Nervoso Central são ainda pouco conhecidos e que a acetilcolinesterase é uma enzima reguladora envolvida na transmissão colinérgica e que indiretamente pode modular a liberação de dopamina, o presente estudo investigou os efeitos da administração aguda de femproporex sobre a atividade da enzima acetilcolinesterase em cérebro de ratos jovens. Ratos Wistar machos jovens receberam uma única injeção de femproporex (6,25, 12,5 ou 25 mg/kg i.p.) ou veículo (Tween 80 2%). Duas horas após a injeção, os ratos foram mortos por decapitação e o cérebro foi removido para avaliação da atividade da acetilcolinesterase. Os resultados mostraram que a administração de femproporex aumentou a atividade da acetilcolinesterase no hipocampo e córtex posterior, enquanto que no córtex pré-frontal, estriado e cerebelo a atividade da enzima não foi alterada. Em conclusão, o presente estudo demonstrou que a administração aguda de femproporex exerce um efeito no sistema colinérgico causando um aumento na atividade da acetilcolinesterase, de um modo dose dependente, no hipocampo e córtex posterior. Assim, sugere-se que o desequilíbrio na homeostase colinérgica pode ser considerado um importante mecanismo fisiopatológico subjacente ao dano cerebral observado em pacientes que utilizam anfetaminas, como o femproporex.

Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p.) or vehicle (2% Tween 80). Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

A primaquina e cloroquina são utilizadas para o tratamento da malária; evidências da literatura sugerem que estes fármacos podem induzir o estresse oxidativo. Neste estudo investigou-se os efeitos da primaquina e cloroquina sobre danos oxidativo e ao DNA no cérebro, fígado e rim de ratos após 7, 14 e 21 dias de administração. Nossos resultados demonstraram que a primaquina causou dano ao DNA no cérebro após 7, 14 e 21 dias, e no fígado após 7 e 14 dias. Além disso, a primaquina aumentou os níveis de TBARS no rim e a carbonilação de proteínas no cérebro após 14 dias, e diminuiu a carbonilação de proteínas no fígado após 7 dias. Enquanto que a cloroquina causou dano ao DNA no rim após 7 e 14 dias, e no fígado e cérebro após 14 e 21 dias, aumentou os níveis de TBARS após 7 dias no rim, e reduziu os níveis de TBARS no cérebro após 21 dias. Além disso, diminuiu a carbonilação de proteínas no fígado após 7 e 14 dias, e no cérebro após 7 e 21 dias. Entretanto, o tratamento com cloroquina durante 14 dias aumentou a carbonilação de proteínas no cérebro e rim. Em conclusão, estes resultados mostraram que o tratamento prolongado com antimaláricos pode afetar adversamente o DNA.

Primaquine and chloroquine are used for the treatment of malaria; evidence from the literature suggests that these drugs may induce oxidative stress. In this study we investigated the effects of primaquine and chloroquine on oxidative damage and DNA damage in brain, liver and kidney of rats after 7, 14 and 21 days of administration. Our results demonstrated that primaquine causes DNA damage in brain after 7, 14 and 21 days, and in liver after 7 and 14 days. Moreover, primaquine increases TBARS levels in the kidney and protein carbonyls in the brain after 14 days, and decreases protein carbonyls in the liver after 7 days. Whereas chloroquine causes DNA damage in the kidney after 7 and 14 days, and in the liver after 14 and 21 days, increases TBARS levels in the kidney after 7 days, and decreases TBARS levels in the brain after 21 days. Moreover, decreases protein carbonyls in the liver after 7 and 14 days, and in the brain after 7 and 21 days. However, chloroquine treatment for 14 days increases protein carbonyls in the brain and kidney. In conclusion, these results showed that prolonged treatment with antimalarial may adversely affect the DNA.

Objective: Several studies support the hypothesis that metabolism impairment is involved in the pathophysiology of depression and that some antidepressants act by modulating brain energy metabolism. Thus, we evaluated the activity of Krebs cycle enzymes, the mitochondrial respiratory chain, and creatine kinase in the brain of rats subjected to prolonged administration of fluvoxamine. Methods: Wistar rats received daily administration of fluvoxamine in saline (10, 30, and 60 mg/kg) for 14 days. Twelve hours after the last administration, rats were killed by decapitation and the prefrontal cortex, cerebral cortex, hippocampus, striatum, and cerebellum were rapidly isolated. Results: The activities of citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV were decreased after prolonged administration of fluvoxamine in rats. However, the activities of complex II, succinate dehydrogenase, and creatine kinase were increased. Conclusions: Alterations in activity of energy metabolism enzymes were observed in most brain areas analyzed. Thus, we suggest that the decrease in citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV can be related to adverse effects of pharmacotherapy, but long-term molecular adaptations cannot be ruled out. In addition, we demonstrated that these changes varied according to brain structure or biochemical analysis and were not dose-dependent.

Introduction: Mitochondrial dysfunction has been postulated to participate in the development of many neuropsychiatric disorders, but there is no consensus as to its role. The aim of this paper is to review recent studies and to outline the current understanding of the association between mitochondrial dysfunction and psychiatric disorders. Methodology: We reviewed articles that evaluated mitochondrial dysfunction and psychiatric disorders, with a particular focus on depression, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, and autism spectrum disorder, and the association between mitochondrial dysfunction and development of these disorders. Results: Evidence suggests that alterations in mitochondrial morphology, brain energy metabolism, and mitochondrial enzyme activity may be involved in the pathophysiology of different neuropsychiatric disorders, given their key role in energy metabolism in the cell. Conclusions: Understanding the interactions between mitochondrial dysfunction and development of psychiatric disorders may help establish more effective therapeutic strategies for these disorders and thus lead to better outcomes for affected subjects.

Objectives: Fenproporex is an amphetamine-based anorectic which is rapidly converted into amphetamine in vivo. Na+, K+-ATPase is a membrane-bound enzyme necessary to maintain neuronal excitability. Considering that the effects of fenproporex on brain metabolism are poorly known and that Na+, K+-ATPase is essential for normal brain function, this study sought to evaluate the effect of this drug on Na+, K+-ATPase activity in the hippocampus, hypothalamus, prefrontal cortex, and striatum of young rats. Methods: Young male Wistar rats received a single injection of fenproporex (6.25, 12.5, or 25 mg/kg intraperitoneally) or polysorbate 80 (control group). Two hours after the last injection, the rats were killed by decapitation and the brain was removed for evaluation of Na+, K+-ATPase activity. Results: Fenproporex decreased Na+, K+-ATPase activity in the striatum of young rats at doses of 6.25, 12.5, and 25 mg/kg and increased enzyme activity in the hypothalamus at the same doses. Na+, K+-ATPase activity was not affected in the hippocampus or prefrontal cortex. Conclusion: Fenproporex administration decreased Na+, K+-ATPase activity in the striatum even in low doses. However, in the hypothalamus, Na+, K+-ATPase activity was increased. Changes in this enzyme might be the result of the effects of fenproporex on neuronal excitability.

Objective: To investigate the effects of cannabidiol (CBD) on mitochondrial complex and creatine kinase (CK) activity in the rat brain using spectrophotometry. Method: Male adult Wistar rats were given intraperitoneal injections of vehicle or CBD (15, 30, or 60 mg/kg) in an acute (single dose) or chronic (once daily for 14 consecutive days) regimen. The activities of mitochondrial complexes and CK were measured in the hippocampus, striatum, and prefrontal cortex. Results: Both acute and chronic injection of CBD increased the activity of the mitochondrial complexes (I, II, II-III, and IV) and CK in the rat brain. Conclusions: Considering that metabolism impairment is certainly involved in the pathophysiology of mood disorders, the modulation of energy metabolism (e.g., by increased mitochondrial complex and CK activity) by CBD could be an important mechanism implicated in the action of CBD.

OBJETIVOS: A olanzapina, uma droga antipsicótica atípica com afinidade por locais de ligação de dopamina, serotonina e histamina, parece se associar a um ganho de peso e a alterações metabólicas consideráveis. O objetivo desse estudo foi avaliar o ganho de peso e as alterações metabólicas em ratos tratados com olanzapina numa dieta hipercalórica. MÉTODOS: Usamos 40 ratos divididos em 4 grupos: Grupo 1, condições padrão de alimento e água (controle); Grupo 2, dieta padrão mais olanzapina; Grupo 3, dieta hipercalórica; e Grupo 4, olanzapina mais dieta hipercalórica. Olanzapina foi administrada por gavagem a uma dose de 3 mg/kg por 9 semanas. RESULTADOS: Não houve alterações significativas nos níveis de colesterol em qualquer um dos grupos. Os níveis de glicose aumentaram no Grupo 3 por volta da quarta semana. Os níveis de triglicerídeos estavam alterados no Grupo 2 ao final do experimento. Os níveis de leptina diminuíram nos Grupos 2 e 4. A atividade do complexo II nos músculos e no fígado se alterou no Grupo 2 (músculos) e nos Grupos 2, 3 e 4 (fígado). A atividade do complexo IV se alterou apenas no fígado no Grupo 2, sem alterações significativas nos músculos. CONCLUSÃO: Esses resultados sugerem que olanzapina se correlaciona ao ganho de peso e aos riscos associados à obesidade.

OBJECTIVES: Olanzapine, an atypical antipsychotic drug with affinities for dopamine, serotonin, and histamine binding sites appears to be associated with substantial weight gain and metabolic alterations. The aim of this study was to evaluate weight gain and metabolic alterations in rats treated with olanzapine on a hypercaloric diet. METHODS: We used 40 rats divided into 4 groups: Group 1, standard food and water conditions (control); Group 2, standard diet plus olanzapine; Group 3, cafeteria diet (hypercaloric); and Group 4, olanzapine plus cafeteria diet. Olanzapine was administered by gavage at a dose of 3 mg/kg for 9 weeks. RESULTS There were no significant changes in the cholesterol levels in any group. Glucose levels increased in Group 3 by the fourth week. Triglyceride levels were altered in group 2 toward the end of the experiment. Leptin levels decreased in Groups 2 and 4. Complex II activity in the muscles and liver was altered in Group 2 (muscle), and Groups 2, 3, and 4 (liver). Complex IV activity was altered only in the liver in Group 2, without significant alterations within the muscles. CONCLUSION: These results suggest that olanzapine is correlated with weight gain and the risks associated with obesity.

OBJETIVO: Um amplo corpo de evidência oriundo de estudos experimentais indica que a sepse se associa com um aumento da produção de espécies de oxigênio reativo, depleção de antioxidantes, e acúmulo de marcadores de estresse oxidativo. Além disto, a disfunção mitocondrial foi implicada na patogênese da síndrome de disfunção de múltiplos órgãos. A citrato sintase é uma enzima que se localiza no interior das células, na matriz mitocondrial, sendo uma etapa importante do ciclo de Krebs; esta enzima foi utilizada como um marcador enzimático quantitativo da presença de mitocôndrias intactas. Assim, investigamos a atividade da citrato sintase no cérebro de ratos submetidos ao modelo sepse com de ligadura e punção do ceco. MÉTODOS: Em diferentes horários (3, 6, 12, 24 e 48 horas) após cirurgia de ligadura e punção do ceco, seis ratos foram sacrificados por decapitação, sendo seus cérebros removidos e dissecados o hipocampo, estriato, cerebelo, córtex cerebral e córtex pré-frontal, e utilizados para determinação da atividade de citrato sintase. RESULTADOS: Verificamos que a atividade de citrato sintase no córtex pré-frontal estava inibida após 12, 24 e 48 horas da ligadura e punção do ceco. No córtex cerebral, esta atividade estava inibida após 3, 12, 24 e 48 horas da ligadura e punção do ceco. Por outro lado a citrato sintase não foi afetada no hipocampo, estriato e cerebelo até 48 horas após a ligadura e punção do ceco. CONCLUSÃO: Considerando-se que é bem descrito o comprometimento da energia decorrente da disfunção mitocondrial na sepse, e que o estresse oxidativo desempenha um papel essencial no desenvolvimento da sepse, acreditamos que o comprometimento da energia pode também estar evolvido nestes processos. Se a inibição da citrato sintase também ocorre em um modelo de sepse, é tentador especular que a redução do metabolismo cerebral pode provavelmente estar relacionada com a fisiopatologia desta doença.

OBJECTIVE: An extensive body of evidence from experimental studies indicates that sepsis is associated with increased reactive oxygen species production, depletion of antioxidants, and accumulation of markers of oxidative stress. Moreover, mitochondrial dysfunction has been implicated in the pathogenesis of multiple organ dysfunction syndrome (MODS). Citrate synthase is an enzyme localized in the mitochondrial matrix and an important component of the Krebs cycle; consequently, citrate synthase has been used as a quantitative enzyme marker for the presence of intact mitochondria. Thus, we investigated citrate synthase activity in the brains of rats submitted to a cecal ligation puncture model of sepsis. METHODS: At several times points (3, 6, 12, 24 and 48 hours) after the cecal ligation puncture operation, six rats were killed by decapitation. Their brains were removed, and the hippocampus, striatum, cerebellum, cerebral cortex and prefrontal cortex were dissected and used to determine citrate synthase activity. RESULTS: We found that citrate synthase activity in the prefrontal cortex was inhibited 12, 24 and 48 hours after cecal ligation puncture. In the cerebral cortex, citrate synthase activity was inhibited 3, 12, 24 and 48 hours after cecal ligation puncture. Citrate synthase was not affected in the hippocampus, striatum or cerebellum up to 48 hours after cecal ligation puncture. CONCLUSION: Considering that energy impairment due to mitochondrial dysfunction in sepsis has been well described and that oxidative stress plays a crucial role in sepsis development, we believe that energy impairment may also be involved in these processes. If citrate synthase inhibition also occurs in a sepsis model, it is tempting to speculate that a reduction in brain metabolism may be related to the pathophysiology of this disease.

O exercício físico aeróbico tem demonstrado benefícios em pesquisas recentes, uma vez que aumenta a resposta oxidativa muscular, porém os efeitos do exercício sobre o cérebro são pouco conhecidos e bastante contraditórios. A inibição da atividade da enzima creatina quinase (CK) está relacionada à patogênese de um grande número de doenças, especialmente no cérebro, e que a disfunção mitocondrial leva ao dano na síntese de ATP. Este trabalho tem como objetivo verificar os efeitos preventivos do exercício físico no hipocampo e córtex cerebral de camundongos submetidos à exposição crônica da fumaça de cigarro. Foram utilizados 24 camundongos C57BL-6 machos, com idade de entre 8-10 semanas, divididos em 4 grupo, foram submetidos a um programa de exercício (natação), cinco vezes por semana, durante 8 semanas, após esse período os animais foram expostos passivamente à fumaça de cigarro por 60 dias consecutivos, 3 vezes ao dia totalizando em 12 cigarros, 4 cigarros por vez, da marca Marlboro vermelho. A atividade enzimática da CK foi determinada em hipocampo e córtex cerebral. Os resultados mostraram que a atividade da enzima CK foi inibida no córtex cerebral dos animais submetidos à inalação da fumaça do cigarro, porém o exercício conseguiu prevenir esta alteração. A atividade da CK não foi alterada no hipocampo dos animais. Essa inibição da CK pela inalação da fumaça do cigarro pode estar relacionada com processos de morte celular. O exercício preventivo mostrou um papel protetor sobre a inibição dessa enzima.

Recent studies have shown the health benefits of physical exercise, increasing the oxidative response of muscle. However, the effects of exercise on the brain are poorly understood and contradictory. The inhibition of creatine kinase (CK) activity has been associated with the pathogenesis of a large number of diseases, especially in the brain. The objective of this study was to determine the preventive effects of physical exercise in the hippocampus and cerebral cortex of mice after chronic cigarette smoke exposure. Eight to 10-week-old male mice (C57BL-6) were divided into four groups and submitted to an exercise program (swimming), 5 times a week, for 8 weeks. After this period, the animals were passively exposed to cigarette smoke for 60 consecutive days, 3 times a day (4 Marlboro red cigarettes per session), for a total of 12 cigarettes. CK activity was measured in cerebral cortex and hippocampal homogenates. Enzyme activity was inhibited in the cerebral cortex of animals submitted to the inhalation of cigarette smoke. However, exercise prevented this inhibition. In contrast, CK activity remained unchanged in the hippocampus. This inhibition of CK by inhalation of cigarette smoke might be related to the process of cell death. Physical exercise played a preventive role in the inhibition of CK activity caused by exposure to cigarette smoke.

Em pacientes com insuficiência renal, a encefalopatia é um problema comum que pode ser provocado pela uremia, deficiência de tiamina, diálise, rejeição de transplante, hipertensão, desequilíbrios hidroeletrolíticos e toxicidades medicamentosas. Em geral a encefalopatia se apresenta como um complexo de sintomas que progride de uma leve obnubilação sensitiva até delírio e coma. Esta revisão discute questões importantes com relação aos mecanismos de base da fisiopatologia da encefalopatia urêmica. A fisiopatologia da encefalopatia urêmica é até hoje incerta, mas postula-se o envolvimento de diversos fatores; trata-se de um processo complexo e provavelmente multifatorial. Distúrbios hormonais, estresse oxidativo, acúmulo de metabólitos, desequilíbrio entre os neurotransmissores excitatórios e inibitórios, e distúrbio do metabolismo intermediário foram identificados como fatores contribuintes. A despeito do progresso continuado na terapêutica, a maior parte das complicações neurológicas da uremia, como a encefalopatia urêmica, não respondem plenamente à diálise e muitas delas são desencadeadas ou agravadas pela diálise ou transplante renal. Por outro lado, estudos prévios demonstraram que a terapia antioxidante pode ser utilizada como terapia coadjuvante para o tratamento destas complicações neurológicas.

In patients with renal failure, encephalopathy is a common problem that may be caused by uremia, thiamine deficiency, dialysis, transplant rejection, hypertension, fluid and electrolyte disturbances or drug toxicity. In general, encephalopathy presents with a symptom complex progressing from mild sensorial clouding to delirium and coma. This review discusses important issues regarding the mechanisms underlying the pathophysiology of uremic encephalopathy. The pathophysiology of uremic encephalopathy up to now is uncertain, but several factors have been postulated to be involved; it is a complex and probably multifactorial process. Hormonal disturbances, oxidative stress, accumulation of metabolites, imbalance in excitatory and inhibitory neurotransmitters, and disturbance of the intermediary metabolism have been identified as contributing factors. Despite continuous therapeutic progress, most neurological complications of uremia, like uremic encephalopathy, fail to fully respond to dialysis and many are elicited or aggravated by dialysis or renal transplantation. On the other hand, previous studies showed that antioxidant therapy could be used as an adjuvant therapy for the treatment of these neurological complications.

A nanopartícula de prata (AgN) é um dos mais proeminentes nanoprodutos, uma vez que a prata exibe propriedades físicas, químicas e biológicas notavelmente incomuns. Creatina quinase (CK) desempenha um papel central no metabolismo de tecidos que consomem muita energia, tais como o cérebro, músculo esquelético e coração, funcionando como um efetivo sistema tampão dos níveis de ATP celular. Uma diminuição na atividade da CK pode alterar a homeostase energética, contribuindo para a morte celular. No presente trabalho nós estudamos o efeito in vitro de AgN na atividade da CK de cérebro, coração e músculo esquelético de ratos. Nossos resultados demonstraram que AgN (10, 25 e 50 mg L-1) in vitro inibiram a atividade da CK em cérebro e músculo esquelético, porém não em coração. Vários trabalhos mostraram que os efeitos citotóxicos da AgN provavelmente envolvem a interação entre íons prata e grupos sulfidrila de proteínas. Nós sugerimos que a AgN inibiu a atividade da CK por meio da interação com grupos tiol da enzima.

One of the most prominent nanoproducts is the silver nanoparticle (AgN), since silver ions exhibit remarkably unusual physical, chemical and biological properties. Creatine kinase (CK) plays a central role in metabolism of high-energy consuming tissues such as brain, skeletal muscle and heart, where it functions as an effective buffering system of cellular ATP levels. A decrease of CK activity may impair energy homeostasis, contributing to cell death. In the present work we studied the in vitro effect of AgN on the activity of CK from rat brain, heart and skeletal muscle. Our results demonstrated that AgN (10, 25 and 50 mg L-1) in vitro inhibited CK from brain and skeletal muscle, but not from heart. Several works showed that AgN cytotoxic effects probably involve interaction between silver ions and sulphydryl groups of proteins. We suggest that AgN inhibited CK activity through interactions with thiol groups of the enzyme.