Most prior studies of the effects of excessive alcohol intake on the adolescent brain examined alcohol use dependent samples with comorbid psychiatric and substance use disorders. In the Cape Town region, we identified a sizeable cohort of adolescents with alcohol use disorders (AUD) without externalizing or other psychiatric disorders. We examined brain morphology in 64 such adolescents compared to age and gender matched healthy controls. Magnetic resonance imaging data were analyzed using FSL’s FIRST software for subcortical volumes, and cortical gray matter (GM) was analyzed using voxel based morphometry (VBM) and regions of interest (ROI) analysis. AUD boys had smaller thalamic and putamen volumes compared to non-drinking boys, while AUD girls had larger thalamic and putamen volumes compared to non-drinking girls. VBM revealed a large region of decreased GM density in AUDs compared to controls located in the left lateral frontal, temporal, and parietal lobes, extending medially deep into the parietal lobe. Smaller GM volume in this region was also present when examined using ROI analysis. Our lack of findings in other brain regions, particularly hippocampus, suggests that reports of smaller brain volumes in adolescent AUDs in the literature are a consequence of psychiatric and substance abuse comorbidities.
Carbon monoxide-releasing molecules are emerging as a new class of pharmacological agents that regulate important cellular function by liberating CO in biological systems. Here, we examined the role of carbon monoxide-releasing molecule 3 (CORM-3) in modulating neuroinflammatory responses in BV-2 microglial cells, considering its practical application as a novel therapeutic alternative in the treatment of stroke. BV-2 microglia cells were incubated for 24 h in normoxic conditions with thrombin alone or in combination with interferon-␥ to simulate the inflammatory response. Cells were also subjected to 12 h of hypoxia and reoxygenated for 24 h in the presence of thrombin and interferon-␥. In both set of experiments, the anti-inflammatory action of CORM-3 was evaluated by assessing its effect on nitric oxide production (nitrite levels) and tumor necrosis factor (TNF)-␣ release. CORM-3 (75 M) did not show any cytotoxicity and markedly attenuated the inflammatory response to thrombin and interferon-␥ in normoxia and to a lesser extent in hypoxia as evidenced by a reduction in nitrite levels and TNF-␣ production. Inactive CORM-3, which does not liberate CO and is used as a negative control, failed to prevent the increase in inflammatory mediators. Blockade of endogenous CO production by tin protoporphyrin-IX did not change the anti-inflammatory activity of CORM-3, suggesting that CO liberated from the compound is responsible for the observed effects. In addition, inhibition of the mitogen-activated protein kinases phosphatidyl inositol 3 kinase and extracellular signal-regulated kinase amplified the anti-inflammatory effect of CORM-3. These results suggest that the anti-inflammatory activity of CORM-3 could be exploited to mitigate microglia activity in stroke and other neuroinflammatory diseases.Stroke is the major cause of disabilities in adults, leaving more than half of the survivors dependent on others for everyday activities (Wolfe et al., 2000). It is also a major cause of dementia, depression, epilepsy, and falls (Rothwell et al., 2004). This pathological event is characterized by blockade of blood supply to the brain and consequently oxygen and glucose deprivation, which lead to necrotic cell death and tissue infarct. Rescuing the surrounding partially ischemic penumbra depends on the severity of brain edema, subsequent neuroinflammation, and production of free radicals.Microglia are the main inflammatory-reacting cells in the brain after ischemia (Suk, 2004). They act through redoxsensitive inflammatory enzymes such as inducible nitric oxide synthase (iNOS) and NAD(P)H oxidase, which produce NO, superoxide, peroxynitrite, and other reactive oxygen species (ROS) that mediate their phagocytic ability. Free radicals generated during the inflammatory process can directly damage neurons by interacting with their lipid-rich membranes or by increasing ␣-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate receptor susceptibility to the toxic effects of glutamate (Zhao et al., 2004).Another important ...
New Findings r What is the central question of this study?Activation of angiotensin-converting enzyme 2, resulting in production of angiotensin-(1-7) and stimulation of its receptor, Mas, exerts beneficial actions in a number cardiovascular diseases, including ischaemic stroke. A potential beneficial role for angiotensin-(1-7) in haemorrhagic stroke has not previously been reported. r What is the main finding and its importance?Central administration of angiotensin-(1-7) into stroke-prone spontaneously hypertensive rats, a model of haemorrhagic stroke, increases lifespan and improves the neurological status of these rats, as well as decreasing microglial numbers in the striatum (implying attenuation of cerebral inflammation). These actions of angiotensin-(1-7) have not previously been reported and identify this peptide as a potential new therapeutic target in haemorrhagic stroke.Angiotensin-(1-7) [Ang-(1-7)] exerts cerebroprotective effects in ischaemic stroke, and this action is associated with a blunting of intracerebral inflammatory processes and microglial activation. Given that intracerebral inflammation and microglial activation play key roles in the mechanism of injury and brain damage in both ischaemic and haemorrhagic stroke, we have investigated the potential beneficial actions of Ang-(1-7) in stroke-prone spontaneously hypertensive rats (spSHRs), an established animal model of hypertensioninduced haemorrhagic stroke. Angiotensin-(1-7) was administered by continuous infusion via the intracerebroventricular route for 6 weeks into spSHRs fed a high-sodium (4%) diet, starting at 49 days of age. This treatment resulted in a significant increase in survival of the spSHRs. Median survival was 108 days in control, artificial cerebrospinal fluid-infused spSHRs and 154 days in Ang-(1-7)-treated spSHRs. This effect was partly reversed by intracerebroventricular infusion of the Mas receptor blocker, A779. This Ang-(1-7) treatment also decreased the number of haemorrhages in the striatum, improved neurological status (reduced lethargy), decreased the number of microglia in the striatum and tended to increase neuron survival at the same site. Importantly, infusions of Ang-(1-7) had no effect on kidney pathology, heart pathology, body weight, serum corticosterone levels or blood pressure. This study is the first to demonstrate the cerebroprotective actions of Ang-(1-7), including increased survival time, in spSHRs. As such, these data reveal a potential therapeutic target for haemorrhagic stroke.
ObjectiveThe objective of this study is to examine white matter microstructure using diffusion tensor imaging (DTI) in a sample of adolescents with alcohol use disorders (AUD) and no psychiatric or substance co-morbidity.MethodsFifty adolescents with AUD and fifty non-alcohol abusing controls matched on gender and age were studied with DTI, neurocognitive testing, and a clinical assessment that included measures of alcohol use and childhood trauma. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were computed, registered to a common template, and voxel-wise statistical analysis used to assess group differences. Associations between regions of altered WM microstructure and clinical or neurocognitive measures were also assessed.ResultsCompared with controls, adolescent drinkers without co-morbid substance abuse or externalizing disorder, showed 1) no regions of significantly lower FA, 2) increased FA in WM tracts of the limbic system; 3) no MD differences; and 4) within the region of higher FA in AUD, there were no associations between FA and alcohol use, cognition, or trauma.DiscussionThe most important observation of this study is our failure to observe significantly smaller FA in this relatively large alcohol abuse/dependent adolescent sample. Greater FA in the limbic regions observed in this study may index a risk for adolescent AUD instead of a consequence of drinking. Drinking behavior may be reinforced in those with higher FA and perhaps greater myelination in these brain regions involved in reward and reinforcement.
Background Disturbed gait and balance are common and important sequelae of chronic alcoholism. We present longitudinal data on recovery of gait and balance in alcoholics 6–15 weeks abstinent at baseline assessment through follow-up assessment 4–16 months after baseline. Methods We performed a follow-up assessment (4–16 months after baseline) of gait and balance functioning in 37 Short-Term (6–15 weeks) Abstinent Alcoholics (STAA), 25 of whom remained abstinent through the follow-up period. Fourteen Non-Substance-Abusing Controls (NSAC) were also brought back for a follow-up assessment to examine practice effects. Results Alcoholics showed gait and balance impairment vs. controls at both the initial and follow-up assessments, showing no improvement in gait and balance measures over the follow-up period. At follow-up, NSAC showed improvement on the Walk on Floor Eyes Closed measure, possibly representing a practice effect not present in STAA. Conclusions The present study finds no improvement from about 10 weeks to about 1 year of abstinence in chronic alcoholics. The study is silent with regard to gait and balance recovery that occurs prior to 10 weeks abstinence, and after the first year of abstinence. Other studies suggest some recovery of gait and balance prior to 10 weeks abstinence, and our recent cross-sectional study (Smith and Fein 2011) suggests that significant additional recovery occurs in the ensuing years.
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