Mitochondrial quality control and neurological disease: an emerging connection

The human brain is a highly complex organ with remarkable energy demands. Although it represents only 2% of the total body weight, it accounts for 20% of all oxygen consumption, reflecting its high rate of metabolic activity. Mitochondria have a crucial role in the supply of energy to the brain. Consequently, their deterioration can have important detrimental consequences on the function and plasticity of neurons, and is thought to have a pivotal role in ageing and in the pathogenesis of several neurological disorders. Owing to their inherent physiological functions, mitochondria are subjected to particularly high levels of stress and have evolved specific molecular quality-control mechanisms to maintain the mitochondrial components. Here, we review some of the most recent advances in the understanding of mitochondrial stress-control pathways, with a particular focus on how defects in such pathways might contribute to neurodegenerative disease

Willing suspension of disbelief: a study in online learning through simulation, and its potential for deeper learning in Higher Education

This article describes the replacement of a 'traditionally taught' law of probate course (lectures and workshops/tutorials) with an on-line collaborative learning exercise using simulation and role-play which is referred to hereafter as the Transactional Learning Project ('TLP'). The article considers the theory that the emotional engagement that comes about through role play in simulation leads to deeper learning, a process Maharg (2010) has dubbed as the 'integration of the cognitive and the affective'. The article includes statistical analysis of student feedback on the TLP in an attempt to measure how easy it is to carry students predisposed to expect information to be 'given' rather than 'acquired' along the journey leading away from traditional didactic teaching. The project was motivated partly by the dearth of such learning practices on the Legal Practice Course. It is suggested that the findings of the project add to the body of research which tends to illustrate the success in terms of student learning from working in leaderless (i.e. where the tutor is absent from the collaborative group) groups engaged in practical tasks involving simulation

Impact of clerkship in the attitudes toward psychiatry among Portuguese medical students

<p>Abstract</p> <p>Background</p> <p>Given the shortage of human resources and the launching of a new Mental Health Plan, recruitment of psychiatrists is currently a major concern in Portugal, as well as in several other countries. Medical students' attitude toward psychiatry has been pointed as a predictor of recruitment. This study aims to evaluate the medical students' perception of psychiatry before and after a clerkship, and the impact on their intention to pursue psychiatry as a future specialty option.</p> <p>Methods</p> <p>Two self-report questionnaires were administered to all 6^thyear students in a medical school in Lisbon, before and after a 4-weeks full-time psychiatric clerkship, in order to evaluate attitudes toward psychiatry and intention to follow psychiatry in the future. Statistical analysis included Wilcoxon and Chi-square tests.</p> <p>Results</p> <p>153 students (60.8% female) filled in both questionnaires (no dropouts). After the clerkship, there was a significant improvement regarding the overall merits of psychiatry, efficacy, role definition and functioning of psychiatrists, use of legal powers to hospitalize patients and specific medical school factors. There was also a significant increase of students decided or considering the possibility to take a residency in psychiatry.</p> <p>However, perceptions of low prestige and negative pressure from family and peers regarding a future choice of psychiatry remained unchanged in about one-third of the students.</p> <p>Conclusions</p> <p>The results indicate clearly that the clerkship had a favorable overall impact on the student attitude towards psychiatry, as well as in the number of students considering a future career in psychiatry. Attitudes toward psychiatry seems a promising outcome indicator of the clerkship's quality, but further research is needed in order to assess its reliability as a sound predictor of recruitment.</p

Olfactory dysfunction, central cholinergic integrity and cognitive impairment in Parkinson’s disease

Olfactory dysfunction is common in subjects with Parkinson’s disease. The pathophysiology of such dysfunction, however, remains poorly understood. Neurodegeneration within central regions involved in odour perception may contribute to olfactory dysfunction in Parkinson’s disease. Central cholinergic deficits occur in Parkinson’s disease and cholinergic neurons innervate regions, such as the limbic archicortex, involved in odour perception. We investigated the relationship between performance on an odour identification task and forebrain cholinergic denervation in Parkinson’s disease subjects without dementia. Fifty-eight patients with Parkinson’s disease (mean Hoehn and Yahr stage 2.5 ± 0.5) without dementia (mean Mini-Mental State Examination, 29.0 ± 1.4) underwent a clinical assessment, [11C]methyl-4-piperidinyl propionate acetylcholinesterase brain positron emission tomography and olfactory testing with the University of Pennsylvania Smell Identification Test. The diagnosis of Parkinson’s disease was confirmed by [11C]dihydrotetrabenazine vesicular monoamine transporter type 2 positron emission tomography. We found that odour identification test scores correlated positively with acetylcholinesterase activity in the hippocampal formation (r = 0.56, P < 0.0001), amygdala (r = 0.50, P < 0.0001) and neocortex (r = 0.46, P = 0.0003). Striatal monoaminergic activity correlated positively with odour identification scores (r = 0.30, P < 0.05). Multiple regression analysis including limbic (hippocampal and amygdala) and neocortical acetylcholinesterase activity as well as striatal monoaminergic activity, using odour identification scores as the dependent variable, demonstrated a significant regressor effect for limbic acetylcholinesterase activity (F = 10.1, P < 0.0001), borderline for striatal monoaminergic activity (F = 1.6, P = 0.13), but not significant for cortical acetylcholinesterase activity (F = 0.3, P = 0.75). Odour identification scores correlated positively with scores on cognitive measures of episodic verbal learning (r = 0.30, P < 0.05). These findings indicate that cholinergic denervation of the limbic archicortex is a more robust determinant of hyposmia than nigrostriatal dopaminergic denervation in subjects with moderately severe Parkinson's disease. Greater deficits in odour identification may identify patients with Parkinson's disease at risk for clinically significant cognitive impairment

Real-time brain computer interface using imaginary movements

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