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To address the role of mixed anxiety/mood disorder on appetitive associative learning, we verify whether previous chronic light deprivation changes ethanol-induced conditioned place preference and its respective expression of c-Fos and pCREB, markers of neuronal activity and plasticity. The experimental group was maintained in light deprivation for 24 h for a period of 4 wk. Subsequently, it was adapted to a standard light-dark cycle for 1 wk. As a control, some mice were maintained in standard cycle for a period of 4 wk (Naïve group). Then, all animals were submitted to behavioral tests to assess emotionality: elevated plus maze; open field; and forced swim. After that, they were submitted to ethanol-induced conditioned place preference. Ninety minutes after the place preference test, they were perfused, and their brains processed for c-Fos and pCREB immunohistochemistry. Light deprivation induced anxiety-like trait (elevated plus maze), despair (forced swim), and hyperlocomotion (open field), common features seen in other animal models of depression. Ethanol-induced conditioned place preference was accompanied by increases on c-Fos and pCREB in the hippocampus, prefrontal cortex and striatum. Interestingly, mice previously submitted to light deprivation did not develop either acquisition and/or expression of ethanol-induced conditioned place preference or increases in c-Fos and pCREB. Therefore, chronic light deprivation mimics several behavioral aspects of other animal models of depression. Furthermore, it could be useful to study the neurochemical mechanisms involved in the dual diagnosis. However, given its likely deleterious effects on appetitive associative memory, it should be used with caution to investigate the cognitive aspects related to the dual diagnosis.

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BACKGROUND: Here we investigated the effects of electroacupuncture over locomotor sensitization induced by ethanol in mice. METHODS: Adult male Swiss mice were daily injected with ethanol (2 g/kg, i.p.) or saline for 21 days (acquisition phase). After 4 days of withdrawal, all animals were challenged with ethanol (1.4 g/kg, i.p.). The locomotor activity during 30 minutes was accessed just after the ethanol challenge. Electroacupuncture at acquisition, expression, or maintenance phases of locomotor sensitization was provided over ST-36 (Zusanli) or PC-6 (Neiguan) as well as concomitantly over these 2 acupoints. One hour after the challenge with ethanol, the animals were decapitated, the hippocampus, striatum, and prefrontal cortex were dissected, and the expression of homer1A mRNA assessed by PCR. RESULTS: Electroacupuncture provided simultaneously over ST-36 and PC-6 (but not to ST-36 or PC-6 alone) inhibited the acquisition, expression, and maintenance of ethanol-induced locomotor sensitization. In addition, electroacupuncture blocked the diminution of homer1A mRNA expression triggered by ethanol in the acquisition (striatum and prefrontal cortex), expression (hippocampus), and in the maintenance (hippocampus and prefrontal cortex) phases. CONCLUSION: Electroacupuncture provided concomitantly over ST-36 and PC-6 prevents the sensitization of the mesocorticolimbic pathway induced by ethanol in mice. In addition, these effects were accompanied by changes in the expression of homer1A. We suggest that electroacupuncture effects over ethanol-induced locomotor sensitization are associated to its ability to modulate homer1A expression and glutamatergic plasticity.

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OBJECTIVE: Lithium has been successfully employed to treat bipolar disorder for decades, and recently, was shown to attenuate the symptoms of other pathologies such as Alzheimer's disease, Down's syndrome, ischemic processes, and glutamate-mediated excitotoxicity. However, lithium's narrow therapeutic range limits its broader use. Therefore, the development of methods to better predict its dose becomes essential to an ideal therapy. METHOD: the performance of adult Wistar rats was evaluated at the open field and elevated plus maze after a six weeks treatment with chow supplemented with 0.255%, or 0.383% of lithium chloride, or normal feed. Thereafter, blood samples were collected to measure the serum lithium concentration. RESULTS: Animals fed with 0.255% lithium chloride supplemented chow presented a higher rearing frequency at the open field, and higher frequency of arms entrance at the elevated plus maze than animals fed with a 50% higher lithium dose presented. Nevertheless, both groups presented similar lithium plasmatic concentration. DISCUSSION: different behaviors induced by both lithium doses suggest that these animals had different lithium distribution in their brains that was not detected by lithium serum measurement. CONCLUSION: serum lithium concentration measurements do not seem to provide sufficient precision to support its use as predictive of behaviors.

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OBJECTIVE: Lithium has been successfully employed to treat bipolar disorder for decades, and recently, was shown to attenuate the symptoms of other pathologies such as Alzheimer's disease, Down's syndrome, ischemic processes, and glutamate-mediated excitotoxicity. However, lithium's narrow therapeutic range limits its broader use. Therefore, the development of methods to better predict its dose becomes essential to an ideal therapy. METHOD: the performance of adult Wistar rats was evaluated at the open field and elevated plus maze after a six weeks treatment with chow supplemented with 0.255 percent, or 0.383 percent of lithium chloride, or normal feed. Thereafter, blood samples were collected to measure the serum lithium concentration. RESULTS: Animals fed with 0.255 percent lithium chloride supplemented chow presented a higher rearing frequency at the open field, and higher frequency of arms entrance at the elevated plus maze than animals fed with a 50 percent higher lithium dose presented. Nevertheless, both groups presented similar lithium plasmatic concentration. DISCUSSION: different behaviors induced by both lithium doses suggest that these animals had different lithium distribution in their brains that was not detected by lithium serum measurement. CONCLUSION: serum lithium concentration measurements do not seem to provide sufficient precision to support its use as predictive of behaviors.

OBJETIVO: Além de ser usado há décadas para tratar distúrbio bipolar, o lítio, mais recentemente, demonstrou-se eficaz para Alzheimer, síndrome de Down, processos isquêmicos e excitotoxicidade mediada por glutamato. Contudo, a estreita janela terapêutica do lítio limita seu uso. Portanto, o estabelecimento de métodos preditivos de dose torna-se importante. MÉTODO: O desempenho de ratos Wistar adultos foi avaliado no campo aberto e labirinto em cruz elevado após seis semanas de tratamento com uma ração suplementada com 0,255 por cento ou 0,383 por cento de cloreto de lítio ou ração normal. Coletou-se amostras de sangue para dosagem plasmática do lítio. RESULTADOS: Os animais alimentados com a ração com 0,255 por cento de cloreto de lítio fizeram mais rearing no campo aberto e tiveram uma maior freqüência de entradas nos braços do labirinto elevado que os animais que ingeriram a dose mais alta. Apesar disso, verificou-se níveis plasmáticos de lítio semelhantes em ambos os grupos. DISCUSSÃO: A variação nos comportamentos destarte a presença de níveis plasmáticos semelhantes sugere que as diferentes doses produziram diferentes concentrações cerebrais não detectadas pela medida plasmática. CONCLUSÃO: Medidas da concentração plasmática de lítio não permitem prever de forma completa seus efeitos comportamentais.

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