Search

Abstract: In this study, we assessed the oxidative stress parameters in rats submitted to an animal model of mania induced by ouabain (OUA), which included the use of lithium (Li) and valproate (VPA). Li and VPA treatment reversed and prevented the OUA-induced damage in these structures, however, this effect varies depending on the brain region and treatment regimen. Moreover, the activity of the antioxidant enzymes, namely, superoxide dismutase (SOD) and catalase (CAT) was found to be increased and decreased, respectively, in the brain of OUA-administered rats. Li and VPA modulated SOD and CAT activities in OUA-subjected rats in both experimental models. Our results support the notion that Li and VPA exert antioxidant-like properties in the brain of rats submitted to animal model of mania induced by ouabain. [ABSTRACT FROM AUTHOR]

Abstract: There is a body of evidence suggesting that BDNF is involved in bipolar disorder (BD) pathogenesis. Intracerebroventricular (ICV) injection of ouabain (OUA), a specific Na+/K+ ATPase inhibitor, induces hyperlocomotion in rats, and has been used as an animal model of mania. The present study aims to investigate the effects of the lithium (Li) and valproate (VPT) in an animal model of mania induced by ouabain. In the reversal model, animals received a single ICV injection of OUA or cerebrospinal fluid (aCSF). From the day following the ICV injection, the rats were treated for 6days with intraperitoneal (IP) injections of saline (SAL), Li or VPT twice a day. In the maintenance treatment (prevention model), the rats received IP injections of Li, VPT, or SAL twice a day for 12days. In the 7th day of treatment the animals received a single ICV injection of either OUA or aCSF. After the ICV injection, the treatment with the mood stabilizers continued for more 6days. Locomotor activity was measured using the open-field test and BDNF levels were measured in rat hippocampus and amygdala by sandwich-ELISA. Li and VPT reversed OUA-related hyperactive behavior in the open-field test in both experiments. OUA decreased BDNF levels in first and second experiments in hippocampus and amygdala and Li treatment, but not VPT reversed and prevented the impairment in BDNF expression after OUA administration in these cerebral areas. Our results suggest that the present model fulfills adequate face, construct and predictive validity as an animal model of mania. [Copyright &y& Elsevier]

Abstract: There is an emerging body of data suggesting that bipolar disorder is associated with DNA damage. Intracerebroventricular (ICV) administration of ouabain in rats results in manic-like alterations. We evaluated DNA damage of peripheral blood, cerebrospinal fluid and hippocampus of rats after ICV ouabain injection. Ouabain-induced hyperlocomotion was examined in an open field. Additionally, we used single cell gel electrophoresis (comet assay) to measure early transient damage in cerebrospinal fluid (CSF), hippocampus and blood; and the micronucleus test to measure persistent damage in total blood samples of rats after ouabain administration. Our findings demonstrated that ouabain induced hyperlocomotion in rats, and this response remained up to 7 days following a single ICV injection. In addition, we observed that the persistent increase in the rat spontaneous locomotion is associated with increased hippocampal and peripheral index of early DNA damage in rats. No significant alterations were observed in the micronucleus frequency in total blood samples of the rats after the ouabain ICV injection. These results suggest that ouabain may induce peripheral and central early DNA damage, but this early damage may be repaired. [Copyright &y& Elsevier]

The present study aimed to investigate the effects of mood stabilizers, specifically lithium (Li) and valproate (VPA), on the PI3K/Akt signaling pathway in the brains of rats subjected to the ouabain (OUA)-induced animal model of mania. In addition, the effects of AR-A014418, a GSK-3β inhibitor, on manic-like behavior induced by OUA were evaluated. In the first experimental protocol Wistar rats received a single ICV injection of OUA or artificial cerebrospinal fluid (aCSF). From the day following ICV injection, the rats were treated for 6 days with intraperitoneal injections of saline, Li or VPA twice a day. In the second experimental protocol, rats received OUA, aCSF, OUA plus AR-A014418, or aCSF plus AR-A014418. On the 7th day after OUA injection, locomotor activity was measured using the open-field test. In addition, we analyzed the levels of p-PI3K, p -MAPK, p -Akt, and p -GSK-3β in the brain of rats by immunoblot. Li and VPA reversed OUA-related hyperactivity. OUA decreased p-PI3K, p-Akt and p-GSK-3β levels. Li and VPA improved these OUA-induced cellular dysfunctions; however, the effects of the mood stabilizers were dependent on the protein and brain region analyzed. In addition, AR-A014418 reversed the manic-like behavior induced by OUA. These findings suggest that the manic-like effects of ouabain are associated with the activation of GSK-3β, and that Li and VPA exert protective effects against OUA-induced inhibition of the GSK-3β pathway. [ABSTRACT FROM AUTHOR]

Objective: To assess the presence of anxiety disorders and quality of life in patients with insulin-dependent type 2 diabetes. Methods: Case-control study of 996 patients with type 2 diabetes and 2,145 individuals without diabetes. The sole inclusion criterion for the case group was insulin-dependent type 2 diabetes. We compared the case and control groups for sociodemographic variables, laboratory and clinical data, and presence of anxiety disorders. Quality of life was evaluated using the WHOQOL-BREF instrument, and the prevalence of anxiety disorder was evaluated by the Mini International Neuropsychiatric Interview (MINI). Results: Patients with diabetes had a higher prevalence of generalized anxiety disorder, panic disorder, and obsessive-compulsive disorder. The presence of these disorders in combination with type 2 diabetes was associated with worse quality of life in the physical, social, psychological, and environmental domains. Conclusions: This study demonstrates the importance of diagnosing and treating anxiety disorders in patients with diabetes, so as to prevent more serious complications associated with these comorbidities. [ABSTRACT FROM AUTHOR]

Abstract: Neonatal Escherichia coli meningitis continues to be an important cause of mortality and morbidity in newborns worldwide. The aim of this study was to investigate the cytokines/chemokines, brain-derived neurotrophic factor (BDNF) levels, blood–brain barrier integrity in neonatal rats following E. coli K1 experimental meningitis infection and subsequent behavioural parameters in adulthood. In the hippocampus, interleukin increased at 96h, IL-6 at 12, 48 and 96h, IL-10 at 96h, cytokine-induced neutrophil chemoattractant-1 at 6, 12, 24, 48 and 96h, and BDNF at 48 and 96h. In the cerebrospinal fluid, tumour necrosis factor alpha levels increased at 6, 12, 24, 48 and 96h. The BBB breakdown occurred at 12h in the hippocampus, and at 6h in the cortex. We evaluated behavioural parameters in adulthood: habituation to the open-field, step-down inhibitory avoidance, object recognition, continuous multiple-trials step-down inhibitory avoidance and forced swimming tasks. In adulthood, the animals showed habituation and aversive memory impairment. The animals needed a significant increase in the number of training periods to learn and not had depressive-like symptoms. [Copyright &y& Elsevier]

Abstract: Although electroconvulsive therapy (ECT) has been used as a treatment for mental disorder since 1930s, little progress has been made in the mechanisms underlying its therapeutic or adverse effects. The aim of this work was to analyze the expression of DARPP-32 (a protein with a central role in dopaminergic signaling) in striatum, cortex, hippocampus and cerebellum of Wistar rats subjected to acute or chronic electroconvulsive stimulation (ECS). Rats were submitted to a single stimulation (acute) or to a series of eight stimulations, applied one every 48 h (chronic). Animals were killed for collection of tissue samples at time zero, 0.5, 3, 12, 24 and 48 h after stimulation in the acute model and at the same time intervals after the last stimulation in the chronic model. Our results indicated that acute ECS produces smaller changes in the expression of DARPP-32 but, interestingly, chronic ECS increased transient expression of DARPP-32 in several time frames, in striatum and hippocampus, after the last stimulation. Results on the expression of proteins involved in signaling pathways are relevant for neuropsychiatric disorders and treatment, in particular ECT, and can contribute to shed light on the mechanisms related to therapeutic and adverse effects. [Copyright &y& Elsevier]