ELECTROENCEPHALOGRAPHY (EEG) AND ITS USE IN MOTOR LEARNING AND CONTROL

Electroencephalography (EEG) is a non-invasive technique of measuring electric currents generated from active brain regions and is a useful tool for researchers interested in motor control. The study of motor learning and control seeks to understand the way the brain understands, plans and executes movement both physical and imagined. Thus, the purpose of this study was to better understand the ways in which electroencephalography can be used to measure regions of the brain involved with motor control and learning. For this purpose, two independent studies were completed using EEG to monitor brain activity during both executed and imagined actions. The first study sought to understand the cognitive demand of altering a running gait and provides EEG evidence of motor learning. 13 young healthy runners participated in a 6-week in-field gait-retraining program that altered running gait by increasing step rate (steps per minute) by 5-10%. EEG was collected while participants ran on a treadmill with their original gait as a baseline measurement. After the baseline collection, participants ran for one minute at the same speed with a 5-10% step rate increase while EEG was collected. Participants then participated in a 6-week in-field gait-retraining program in which they received bandwith feedback while running in order to learn the new gait. After completing the 6-week training protocol, participants returned to the lab for post training EEG collection while running with the new step rate. Power spectral density plots were generated to measure frequency band power in all gait-retraining phases. Results in the right prefrontal cortex showed a significant increase in beta (13-30 Hz) while initially running with the new gait compared to the baseline step rate. Previous work suggests the right prefrontal cortex is involved with the inhibition of a previously learned behavior and thus, our results suggest an increase in cognitive load to inhibit the previous full stride motion. After training, this increase in beta over the right prefrontal cortex decreased, suggesting motor adaptations had occurred as a result of motor learning. These results give promising evidence for a new method of ensuring permanent changes in performance that will benefit rehabilitation and athletic performance training programs. The second study in this project sought to understand differences in right and left-handers as they mentally simulate movement. 24 right and left-handed individuals (12 right-handers, 12 left-handers) were shown pictures of individual hands on a screen while EEG was collected. Previous research has shown than while solving this task, participants mentally rotate a mental representation of their own hand to determine the handedness of the image. Event-related potential results showed that right-handers had an earlier and greater activation in the parietal regions than left-handers, whereas left-handers had a later and greater activation in the motor related brain regions compared to right-handers. These results suggest differing strategies while mentally solving motor related tasks between right and left-handers. We speculate this is a result of left-handers' need to adapt to a majorly right-hand dominant environment. Both these studies show the benefits of using EEG to understand the motor system in physically executed and imagined actions

Stochastic variation of transcript abundance in C57BL/6J mice

<p>Abstract</p> <p>Background</p> <p>Transcripts can exhibit significant variation in tissue samples from inbred laboratory mice. We have designed and carried out a microarray experiment to examine transcript variation across samples from adipose, heart, kidney, and liver tissues of C57BL/6J mice and to partition variation into within-mouse and between-mouse components. Within-mouse variance captures variation due to heterogeneity of gene expression within tissues, RNA-extraction, and array processing. Between-mouse variance reflects differences in transcript abundance between genetically identical mice.</p> <p>Results</p> <p>The nature and extent of transcript variation differs across tissues. Adipose has the largest total variance and the largest within-mouse variance. Liver has the smallest total variance, but it has the most between-mouse variance. Genes with high variability can be classified into groups with correlated patterns of expression that are enriched for specific biological functions. Variation between mice is associated with circadian rhythm, growth hormone signaling, immune response, androgen regulation, lipid metabolism, and the extracellular matrix. Genes showing correlated patterns of within-mouse variation are also associated with biological functions that largely reflect heterogeneity of cell types within tissues.</p> <p>Conclusions</p> <p>Genetically identical mice can experience different individual outcomes for medically important traits. Variation in gene expression observed between genetically identical mice can identify functional classes of genes that are likely to vary in the absence of experimental perturbations, can inform experimental design decisions, and provides a baseline for the interpretation of gene expression data in interventional studies. The extent of transcript variation among genetically identical mice underscores the importance of stochastic and micro-environmental factors and their phenotypic consequences.</p

Reduced antioxidant defense in early onset first-episode psychosis: a case-control study

Background:Our objective is to determine the activity of the antioxidant defense system at admission in patients with early onset first psychotic episodes compared with a control group. Methods: Total antioxidant status (TAS) and lipid peroxidation (LOOH) were determined in plasma. Enzyme activities and total glutathione levels were determined in erythrocytes in 102 children and adolescents with a first psychotic episode and 98 healthy controls. Results: A decrease in antioxidant defense was found in patients, measured as decreased TAS and glutathione levels. Lipid damage (LOOH) and glutathione peroxidase activity was higher in patients than controls. Our study shows a decrease in the antioxidant defense system in early onset first episode psychotic patients. Conclusions: Glutathione deficit seems to be implicated in psychosis, and may be an important indirect biomarker of oxidative stress in early-onset schizophrenia. Oxidative damage is present in these patients, and may contribute to its pathophysiology

Oncoplastic Breast Consortium consensus conference on nipple-sparing mastectomy.

Purpose Indications for nipple-sparing mastectomy (NSM) have broadened to include the risk reducing setting and locally advanced tumors, which resulted in a dramatic increase in the use of NSM. The Oncoplastic Breast Consortium consensus conference on NSM and immediate reconstruction was held to address a variety of questions in clinical practice and research based on published evidence and expert panel opinion. Methods The panel consisted of 44 breast surgeons from 14 countries across four continents with a background in gynecology, general or reconstructive surgery and a practice dedicated to breast cancer, as well as a patient advocate. Panelists presented evidence summaries relating to each topic for debate during the in-person consensus conference. The iterative process in question development, voting, and wording of the recommendations followed the modified Delphi methodology. Results Consensus recommendations were reached in 35, majority recommendations in 24, and no recommendations in the remaining 12 questions. The panel acknowledged the need for standardization of various aspects of NSM and immediate reconstruction. It endorsed several oncological contraindications to the preservation of the skin and nipple. Furthermore, it recommended inclusion of patients in prospective registries and routine assessment of patient-reported outcomes. Considerable heterogeneity in breast reconstruction practice became obvious during the conference. Conclusions In case of conflicting or missing evidence to guide treatment, the consensus conference revealed substantial disagreement in expert panel opinion, which, among others, supports the need for a randomized trial to evaluate the safest and most efficacious reconstruction techniques

Suicide and personality

Objective: Suicide is one of the most important public health problems. Suicide, which needs to be discussed as a part of preventive mental health, has a wide range of causes. Temperament is genetic and structural behavioral characteristics that individuals have in their nature and cannot change for a whole-of-life. On the other hand, character is discussed as a concept, which is affected by education and environmental factors and can change in the course of time. In this study, we aimed to determine the discriminating personality characteristic of suicide attempters compared to healthy control subjects. Methods: Attempted suicide cases (n=69) who applied to Gaziantep University, Medicine Faculty, Emergency Service between May 2003 and August 2005 and who were asked to be assessed as psychiatrically were assessed according to DSM-IV diagnosis criterion and Tempera-ment and Character Inventory (TCI-240 items), Beck Depression Inventory (BDI), and Beck Hopelessness Scale (BHS) were employed to these cases and personality profiles were compared to control group including age and gender matched individuals who do not have any lifetime history of mental disorders (n=77) Results: Suicide attempters showed higher scores in harm avoidance, self-transcendence and lower scores in self-directedness, cooperativeness, and reward dependence when compared to controls. Beck hopelessness scale is positively correlated with harm avoidance score and reward dependence, persistence, self-directedness, cooperativeness scores negatively correlated in suicide group. In attempted suicide group, when we compared TCI scores within genders, responsibility scores was higher in men whereas, fear of uncertainty, virtuousness, and mercifulness subscores were higher in women. As for control group sentimentality, attachment and empathy subscores were higher in women. Conclusion: Temperament and character features of suicide attempters show significant differences compared with healthy control group. Determining personality profile among suicide attempters may be useful in employing different treatment approaches. (Anatolian Journal of Psychiatry 2008; 9:232-237

Hydroxylase 1 Gene 218 A > C Polymorphism

Objective: Considering the suggested association of tryptophan hydroxylase gene 1 (TPH1) polymorphism with some psychiatric disorders and studies concerning serotonin's effect on TPH 1 gene, brain and the neurotransmitter monoamines, as well as the studies performed on the serotonin levels in cerebrospinal fluid of bipolar patients, we aimed to investigate the frequencies and distribution of TPH 1 gene 218 A>C (rs1800532) polymorphism; A/A, A/C and C/C genotypes in bipolar patients and healthy control subjects for the first time in Turkish population (1-2).Methods: One hundred and sixteen adult patients who applied to the Mood Disorders Unit of Psychiatry Department, Medical School of Gaziantep University, and diagnosed with bipolar disorder (BD) according to DSM-IV diagnostic criteria were included in the study. One hundred and fifty healthy volunteers, a hospital staff at Gaziantep University, were involved as the control group.Results: In female patients, the frequency of A/A genotype was found to be higher than in the females in the control group. No significant difference was detected between patient and control groups in terms of age and gender distribution. The distribution of A/A, A/C and C/C genotypes were similar in patient and control groups.Conclusion: The distribution of TPH1 gene 218 A>C polymorphism was found to be significantly different between female patients and females in the control group. This result can be explicated as being one of the possible reasons for different course of bipolar disorder in male and female patients. (Archives of Neuropsychiatry 2010; 47: 96-100

evaluation of oxidant-antioxidant status

Objectives: Various psychological, social, genetic, biochemical, factors are to be involved in the etiology of OCD. Some molecules of free radicals are also found to play role in OCD. To the best of our knowledge, there has been no study, regarding the role of free radicals in the pathogenesis of OCD, from a general antioxidant aspect of view. Therefore, in this present cross-sectional study, we aimed to assess whether antioxidant-oxidant status is associated with OCD and call be used or not as a biological marker regarding that disorder.Methods: 37 OCD patients diagnosed according to DSM-IV and as control group forty healthy subjects were included to the study. Venous blood samples were collected once. The total oxidant status, antioxidant status and oxidative stress index of the plasma were measured using a novel automated colorimetric measurement method.Results: There was not a significant difference between only OCD and all patients in all measures (TOS: Z= - 1.453,p 0.521; TAS: Z= -0.151, p = 0.880; OSI: Z= - 0.679p = 0.497). TAS levels were both higher than controls in only OCD groups and all patients (Z =-5.538, p < 0.001 and Z = - 6.394, p < 0.001 respectively). TOS and OSI of both patient groups were significantly lower than controls (TOS: Z - 5.131, p < 0.001; OSI: Z = - 5.105,p < 0.001 and TOS: Z = - 5.979,p < 0.001; OSI: Z = - 5.862,p < 0.001). In only OCD group, illness duration was correlated with TOS and OSI (r(0) = 0,44, p = 0.023, n = 26 and r(0) = 0.44, p = 0.026, n = 26 respectively) but not with TAS.Conclusion: Our study found an overall oxidative imbalance shifted towards antioxidant side in OCD which may be due to either a rebound phenomenon or chronicity of the condition. (c) 2007 Elsevier Inc. All rights reserved

disorder: a case control study

Background: Alterations in ceruloplasmin are currently assumed as one of the mechanisms underlying the development of a number of neurodegenerative disorders. Several studies indicate that elevated serum ceruloplasmin levels may play a role in schizophrenia by exacerbating or perpetuating dopaminergic dysregulation. No study investigating the relationship between ceruloplasmin and obsessive-compulsive disorder (OCD) has been published to date. Nowadays OCD is increasingly speculated to be a different disorder than other anxiety disorders, and rather is considered to be more similar to psychotic disorders. The objective of this study to explore whether there is an association of ceruloplasmin with OCD as in schizophrenia.Method: 26 pure OCD and 9 co-morbid OCD patients from Gaziantep University Sahinbey Research Hospital, Psychiatry Clinics, diagnosed according to the DSM IV and 40 healthy controls were included in the study. Blood samples were collected; ceruloplasmin levels were measured.Results: The mean ceruloplasmin level in pure OCD patients, co-morbid OCD patients, and control group persons were 544.46 +/- 26.53, 424.43 +/- 31.50 and 222.35 +/- 8.88 U/L respectively. Results of all 3 groups differ significantly. Positive predictive value of ceruloplasmin for that cut-off point is 31/31 (100%) and negative predictive value is 40/44 (91%) in our group.Conclusion: Although the nature of relationship is not clear there was an association between ceruloplasmin levels and OCD in our study