Tissue cultures from adult human postmortem subcortical brain areas

Animal models used to study human aging and neurodegeneration do not display all symptoms of these processes as they are found in humans. Recently, we have shown that many cells in neocortical slices from adult human postmortem brain may survive for extensive periods in vitro. Such cultures may enable us to study age and disease related processes directly in human brain tissue. Here, we present observations on subcortical brain tissu

Surface EMG models: properties and applications.

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Parcellating cognitive heterogeneity in early psychosis-spectrum illnesses: A cluster analysis

Cognitive impairment is argued to represent a core feature of psychosis-spectrum illnesses. However, within-diagnosis heterogeneity is common, and risk factors for poor cognition remain to be examined after statistically accounting for heterogeneity. Accordingly, we used a data-driven technique (cluster analysis) to empirically-derive cognitive clusters across diagnoses and examined whether concurrent substance use or a history of a neurodevelopmental/behavioral disorder differed between clusters. Data from 135 young help-seekers (aged 12–30 years) with a psychosis-spectrum illness were retrospectively analyzed. Ward's hierarchical cluster analysis classified three cognitive clusters characterized by: (1) normal-range; (2) mixed; and (3) grossly-impaired performance. Despite mostly comparable clinical and demographic measures, cluster 1 had superior socio-occupational functioning and the highest estimated premorbid IQ, followed sequentially by clusters 2 and 3. Proportions of cannabis and amphetamine users did not differ significantly across clusters, nor did rates of patients with a neurodevelopmental/behavioral disorder history. Cluster 3 was however comprised of fewer ‘risky’ drinkers, possibly reflecting reduced opportunity for social drinking associated with cognitive impairment. Estimated premorbid IQ predicted cluster membership (2 vs. 1 & 3 vs. 1), as did clinician-rated socio-occupational functioning and ‘not being enrolled in school or tertiary education’ (3 vs. 1). Our results suggest that concurrent substance use and history of a neurodevelopmental/behavioral disorder do not adequately explain cluster-level cognitive variance in this sample. Future work should integrate neurobiological measures associated with cognition (e.g. white matter integrity) to discern whether clusters reflect neurobiological subtypes better representative of pathophysiology than present symptom-based classifications.This work was supported by a Research Training Program stipend through the University of Sydney awarded to J.J.C. and a National Health and Medical Research Council Australia Fellowship (no. 511921 ) awarded to I.B.H. These funders had no role in the design and conduct of the study; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.Scopu

Electrophysiological correlates of CU traits show abnormal regressive maturation in adolescents with conduct problems

Callous/unemotional (CU) temperament traits may denote a more severe form of conduct disorder (CD) and have been associated with abnormal cortical thinning. The present study investigated the maturational decline in N200 amplitude, and the association between N200 amplitude and callous/unemotional traits, in adolescents with CD. Twenty adolescent males (aged 10-18. years old) with CD were age-matched to 27 clinical controls with Attention Deficit Hyperactivity Disorder (ADHD) and 30 non-clinical, typically developing controls. Participants completed a visual continuous performance task. As expected, N200 amplitude in response to background stimuli was inversely associated with age in controls (at frontal and temporal brain regions). Similar associations were seen in clinical controls. In contrast, the CD group showed a significant positive correlation between age and the right temporal N200 amplitude. Further, CU traits were positively correlated with N200 amplitude at midline frontal and temporal electrodes, even after covarying for age. These results highlight links between CU traits and abnormal neurodevelopment as indexed by N200 amplitude. This is in line with an impairment or delay in regressive maturational changes such as cortical thinning, as suggested by neuroimaging studies, which may underlie the persistence of certain psychopathic tendencies. © 2012 Elsevier Ltd

Effects of sex on brain maturation as measured by event-related potentials

Little is known about how sex influences functional brain maturation. The current study investigated sex differences in the maturation of event-related potential (ERP) amplitudes during an auditory oddball task (N = 170; age = 6-17 years). Performance improved with age. N200 amplitude declined with age: parietal sites showed earlier development than temporal and frontal locations. Girls showed greater bilateral frontal P300 amplitude development, approaching the higher values observed in boys during childhood. After controlling for age, right frontal P300 amplitude was associated with reaction time in girls. The findings demonstrate sex differences in ERP maturation in line with behavioral and neuroimaging studies. © 2012 Copyright Taylor and Francis Group, LLC

The myofeedback-based teletreatment system and its evaluation

The myofeedback-based teletreatment system allows patients to receive tactile and/or visual feedback on muscle activity and muscle relaxation times. Health-care professionals can analyse muscle activity and muscle relaxation times and provide guidance to the patient on the course of treatment. The system was evaluated in a small clinical trial. Qualitative data were obtained by interviews and visual inspection of graphical patient data during the trial. Quantitative data were based on post-trial data analysis. We used a revised version of the information systems success model to evaluate the teletreatment system, and focused on the success categories of system use and user satisfaction. The evaluation found good input data quality, system quality and information quality. Both system use and user satisfaction were good. Thus the teletreatment system appears suitable for small scale clinical deployment. However, the sensory components suffered from heavy use and embedded software problems which made them unreliable. Large scale deployment requires improvement in terms of durability and reliability of the system's sensors.\ud \u

Mutant ubiquitin epxressed in Alzheimer's disease causes neuronal death

Ubiquitin-

Cells in human post-mortem brain tissue slices remain alive for several weeks in culture

Animal models for human neurological and psychiatric diseases only partially mimic the underlying pathogenic processes. Therefore, we investigated the potential use of cultured postmortem brain tissue from adult neurological patients and controls. The present study shows that human brain tissue slices obtained by autopsy within 8 h after death can be maintained in vitro for extended periods (up to 78 days) and can be manipulated experimentally. We report for the first time that 1) neurons and glia in such cultures could be induced to express the reporter gene LacZ after transduction with adeno-associated viral vectors and 2) cytochrome oxidase activity could be enhanced by the addition of pyruvate to the medium. These slice cultures offer new opportunities to study the cellular and molecular mechanisms of neurological and psychiatric diseases and new therapeutic strategie