These findings demonstrate that exercise training in heart failure patients results in dramatic reductions in directly recorded resting sympathetic nerve activity. In fact, MSNA was no longer greater than in trained, healthy controls.

Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 19 samples worldwide. Healthy brain aging was estimated by predicting chronological age (18-75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 952 male and 1236 female controls from the ENIGMA MDD working group. The learned model coefficients were applied to 927 male controls and 986 depressed males, and 1199 female controls and 1689 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted "brain age" and chronological age was calculated to indicate brain-predicted age difference (brain-PAD). On average, MDD patients showed a higher brain-PAD of +1.08 (SE 0.22) years (Cohen's d = 0.14, 95% CI: 0.08-0.20) compared with controls. However, this difference did not seem to be driven by specific clinical characteristics (recurrent status, remission status, antidepressant medication use, age of onset, or symptom severity). This highly powered collaborative effort showed subtle patterns of age-related structural brain abnormalities in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the clinical value of these brain-PAD estimates.

Bipolar disorder (BD) is a major public health problem characterized by progressive functional impairment. A number of clinical variables have been associated with progression of the disease, most notably number of affective episodes and presence of psychotic symptoms, both of which correlate with greater cognitive impairment, lower response rates for lithium, and possibly lower levels of neurotrophic factors. Oxidative damage to cytosine and guanosine (8-OHdG) has been described as a modulator of DNA methylation, but the extent of DNA oxidative damage involvement in BD remains unclear. The aim of this study was to evaluate the extent of DNA oxidative damage to 8-OHdG and 5-methylcytosine (5-HMec), as well as global methylation (5-Mec), in BD patients and healthy controls. Potential association with clinical variables was also investigated. DNA levels of 8-OHdG, 5-HMec and 5-Mec were measured in 50 BD type I patients and 50 healthy controls. DNA 8-OHdG levels were higher in BD patients compared to healthy controls and found to be positively influenced by number of previous manic episodes. BD subjects had lower levels of 5-HMec compared to controls, whereas this measure was not influenced by the clinical features of BD. Number of manic episodes was correlated with higher levels of 8-OHdG, but not of 5-Mec or 5-HMec. Lower demethylation activity (5-HMec) but no difference in global 5-Mec levels was observed in BD. This finding suggests that oxidative damage to 8-OHdG might be a potential marker of disease progression, although further prospective cross-sectional studies to confirm neuroprogression in BD are warranted.

Objective:Oxidative stress and mitochondrial dysfunction are 2 closely integrated processes implicated in the physiopathology of bipolar disorder. Advanced proton magnetic resonance spectroscopy techniques enable the measurement of levels of lactate, the main marker of mitochondrial dysfunction, and glutathione, the predominant brain antioxidant. The objective of this study was to measure brain lactate and glutathione levels in bipolar disorder and healthy controls.Methods:Eighty-eight individuals (50 bipolar disorder and 38 healthy controls) underwent 3T proton magnetic resonance spectroscopy in the dorsal anterior cingulate cortex (2x2x4.5cm3) using a 2-D JPRESS sequence. Lactate and glutathione were quantified using the ProFit software program.Results:Bipolar disorder patients had higher dorsal anterior cingulate cortex lactate levels compared with controls. Glutathione levels did not differ between euthymic bipolar disorder and controls. There was a positive correlation between lactate and glutathione levels specific to bipolar disorder. No influence of medications on metabolites was observed.Conclusion:This is the most extensive magnetic resonance spectroscopy study of lactate and glutathione in bipolar disorder to date, and results indicated that euthymic bipolar disorder patients had higher levels of lactate, which might be an indication of altered mitochondrial function. Moreover, lactate levels correlated with glutathione levels, indicating a compensatory mechanism regardless of bipolar disorder diagnosis.

Dopamine (DA) is considered to be an important neurotransmitter in the control of impulsive behavior, however, its underlying mechanisms have not been fully elucidated. Catechol-O-methyltransferase (COMT) is a key enzyme in the catabolism of DA within the prefrontal cortex (PFC) and has been suggested to play a role in the mediation of impulsive behavior. The COMT single nucleotide polymorphism (SNP) rs4680 (Val158Met) Met allele has been shown to decrease COMT enzyme activity and is associated with improved PFC cognitive function (intelligence and executive functions). Studies have associated the rs4680 genotype with impulsivity as a symptom in attention deficit hyperactivity disorder and substance abuse. However, only a few studies have assessed the effects of rs4680 on impulsiveness in healthy subjects, the results of which remain controversial. The Barratt Impulsiveness Scale (BIS-11) was applied to 82 healthy volunteers (including 42 females) who were genotyped for COMT rs4680. Subjects carrying the Met/Met genotype scored higher for the BIS-11 second-order factor Non-planning than carriers of the Val/Val genotype. No interaction between gender genotype was detected. Age, gender and education had no effect on the results. The COMT rs4680 Met/Met genotype was associated with higher impulsivity on the BIS-11 second-order factor Non-planning. These results suggest that COMT enzyme activity may be important in the regulation of impulsiveness among young adults. Further studies involving larger samples should be conducted to confirm the results of the present study.

The hippocampus consists of anatomically and functionally distinct subfields that may be differentially involved in the pathophysiology of bipolar disorder (BD). Here we, the Enhancing NeuroImaging Genetics through Meta-Analysis Bipolar Disorder workinggroup, study hippocampal subfield volumetry in BD. T1-weighted magnetic reso-

B-cell lymphoma 2 (Bcl-2) is an important regulator of cellular plasticity and resilience. In bipolar disorder (BD), studies have shown a key role for a Bcl-2 gene single-nucleotide polymorphism (SNP) rs956572 in the regulation of intracellular calcium (Ca(2+)) dynamics, Bcl-2 expression/levels, and vulnerability to cellular apoptosis. At the same time, Bcl-2 decreases glutamate (Glu) toxicity in neural cells. Abnormalities in Glu function have been implicated in BD. In magnetic resonance spectroscopy (MRS) studies, anterior cingulated cortex (ACC) Glu levels have been reported to be increased in bipolar depression and mania, but no study specifically evaluated ACC Glu levels in BD-euthymia. Here, we compared ACC Glu levels in BD-euthymia compared with healthy subjects using (1)H-MRS and also evaluated the selective role of the rs956572 Bcl-2 SNP in modulating ACC Glu and Glx (sum of Glu and glutamine) in euthymic-BD. Forty euthymic subjects with BD type I and forty healthy controls aged 18-40 were evaluated. All participants were genotyped for Bcl-2 rs956572 and underwent a 3-Tesla brain magnetic resonance imaging examination including the acquisition of an in vivo PRESS single voxel (2 cm(3)) (1)H-MRS sequence to obtain metabolite levels from the ACC. Euthymic-BD subjects had higher Glu/Cre (creatine) and Glx/Cre compared with healthy controls. The Bcl-2 SNP AA genotype was associated with elevated ACC Glu/Cre and Glx/Cre ratio in the BD group but not in controls. The present study reports for the first time an increase in ACC Glu/Cre and Glx/Cre ratios in BD-euthymia. Also, Bcl-2 AA genotype, previously associated with lower Bcl-2 expression and increase intracellular Ca(2+), showed to be associated with increased ACC Glu and Glx levels in euthymic-BD subjects. The present findings reinforce a key role for glutamatergic system dysfunction in the pathophysiology of BD, potentially involving modulatory effects by Bcl-2 in the ACC.

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