20 research outputs found
Effect of Five-Consecutive-Day Exposure to an Anxiogenic Stressor on Sleep-Wake Activity in Rats
Repeated exposure to an anxiogenic stressor (AS) is a known environmental factor for the development of depression, yet the progression of sleep-wake (S-W) changes associated with the onset of AS-induced depression (ASID) is not completely understood. Thus, the aim of this study was to identify these progressive S-W changes by developing ASID in rats, via repeated exposure to an AS, and compare this ASID-associated sleep phenotype with the sleep phenotype of human depression. To achieve this aim, rats were first recorded for a 6 h period of baseline S-W activity without AS. Then, rats were subjected to 5 days of AS [Day 1: inescapable foot-shock; 5 trials of 3 s foot-shocks (1.0 mA) at 3 min intervals; Days 3–5: 15 trials of 5 s foot-shocks at 45 s intervals]. S-W activity was recorded for 6 h immediately after each AS treatment session. Two days later rats were again recorded for 6 h of S-W activity, but with no exposure to the AS (NASD). Compared to the baseline day: Day 1 of AS (ASD-1) increased wakefulness, slow-wave sleep (SWS) latency, and rapid-eye movement (REM) sleep latency, but decreased the total amount of REM sleep; ASD-2 animals remained awake throughout the 6 h S-W recording period; ASD-3, ASD-4, and ASD-5 (ASDs-3–5) decreased wakefulness, SWS latency, and REM sleep latency, but increased the total amount of REM sleep. Interestingly, these results reveal that initial exposure to the AS versus later, repeated exposure to the AS produced opposing S-W changes. On NASD, animals exhibited baseline-like S-W activity, except slightly less REM sleep. These results suggest that repeated AS produces a sleep phenotype that resembles the sleep phenotype of depression in humans, but consistent re-exposure to the AS is required. These results are promising because the methodological simplicity and reversibility of the ASID-associated S-W phenotype could be more advantageous than other animal models for studying the pathophysiological mechanisms that underlie the expression of ASID
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Zonisamide, Topiramate, and Levetiracetam: Efficacy and Neuropsychological Effects in Alcohol Use Disorders
Abstract The anticonvulsant topiramate not only decreases ethanol consumption in alcohol dependence (AD) but also may produce several adverse events including cognitive impairment. Zonisamide is a structurally related anticonvulsant that is a promising agent for the treatment of AD and may have greater tolerability than topiramate. This study evaluated the effects of zonisamide (400 mg/d) on alcohol consumption and its neurotoxic effects in subjects with AD. A double-blind placebo-controlled clinical trial was conducted using 2 comparator anticonvulsant drugs, topiramate (300 mg/d) and levetiracetam (2000 mg/d), which does not impair cognition. Study medications were administered for 14 weeks, including a 2-week taper period. Medication adherence was facilitated using Brief Behavioral Compliance Enhancement Treatment. The neurotoxicity of the study drugs was assessed using neuropsychological tests and the AB-Neurotoxicity Scale. Compared with placebo, both zonisamide and topiramate produced significant reductions in the drinks consumed per day, percent days drinking, and percent days heavy drinking. Only the percent days heavy drinking was significantly decreased in the levetiracetam group. The topiramate cell was the only group that had a significant increase on the mental slowing subscale of the Neurotoxicity Scale compared with placebo at study weeks 11 and 12. Topiramate and zonisamide both produced modest reductions in verbal fluency and working memory. These findings indicate that zonisamide may have efficacy in the treatment of AD, with effect sizes similar to topiramate. Both of these drugs produced similar patterns of cognitive impairment, although only the topiramate group reported significant increases in mental slowing
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Clinicians on the front line: active management of depression and anxiety in primary care
Primary-care practitioners confront myriad issue in managing their patients with depression and/or anxiety. Understanding the scope and epidemiology of these disorders is essential to understanding their shared characteristics. Do we always recognize these patients in practice? What are the barriers to diagnosis and treatment, and how can they overcome? What are the treatment options of these sometimes life-altering conditions, and how do we choose from among the many that exist
Yoga Asana Sessions Increase Brain GABA Levels: A Pilot Study
Objectives:
The aim of this study was to compare changes in brain gamma-aminobutyric (GABA) levels associated with an acute yoga session versus a reading session. It was hypothesized that an individual yoga session would be associated with an increase in brain GABA levels.
Design:
This is a parallel-groups design.
Settings/Location:
Screenings, scan acquisitions, and interventions took place at medical school-affiliated centers.
Subjects:
The sample comprised 8 yoga practitioners and 11 comparison subjects.
Interventions:
Yoga practitioners completed a 60-minute yoga session and comparison subjects completed a 60-minute reading session.
Outcome Measures:
GABA-to-creatine ratios were measured in a 2-cm axial slab using magnetic resonance spectroscopic imaging immediately prior to and immediately after interventions.
Results:
There was a 27% increase in GABA levels in the yoga practitioner group after the yoga session (0.20 mmol/kg) but no change in the comparison subject group after the reading session ( -0.001 mmol/kg) (t = -2.99, df = 7.87, p = 0.018).
Conclusions:
These findings demonstrate that in experienced yoga practitioners, brain GABA levels increase after a session of yoga. This suggests that the practice of yoga should be explored as a treatment for disorders with low GABA levels such as depression and anxiety disorders. Future studies should compare yoga to other forms of exercise to help determine whether yoga or exercise alone can alter GABA levels
Cerebellar gray matter volume correlates with duration of cocaine use in cocaine-dependent subjects
This study was conducted to explore differences in gray and white matter volume between cocaine-dependent and healthy comparison subjects using optimized voxel-based morphometry (VBM). Brain magnetic resonance imaging (MRI) and neuropsychological function tests were performed for 40 cocaine-dependent subjects (41.4+/-6.9 years, 27 men) and 41 healthy age- and sex-matched comparison subjects (38.7+/-8.8 years, 26 men). Optimally normalized whole brain MR images were segmented, modulated, smoothed, and compared between groups with statistical parametric mapping. The cocaine-dependent group had lower gray matter volumes in bilateral premotor cortex (Brodmann area (BA) 6, 8; 16.6%), right orbitofrontal cortex (BA 10, 15.1%), bilateral temporal cortex (BA 20, 38; 15.9%), left thalamus (12.6%), and bilateral cerebellum (13.4%) as well as lower right cerebellar white matter volume (10.0%) relative to the comparison group at a corrected p<0.05 for multiple comparisons. Duration of cocaine use negatively correlated with right and left cerebellar gray matter volumes (r=-0.37, r=-0.39, respectively). In cocaine-dependent subjects, lower cerebellar hemispheric gray and white matter volumes were correlated with deficits in executive function and decreased motor performance. This study reports that cocaine-dependent subjects have lower gray matter volumes in cerebellar hemispheres as well as in frontal, temporal cortex, and thalamus. These findings are the first to suggest that the cerebellum may be vulnerable to cocaine-associated brain volume changes, and that cerebellar deficits may contribute to neuropsychological deficits and motor dysfunction frequently observed in cocaine-dependent subjects