What is the role of muscle receptors in proprioception?

The role of muscle afferents is discussed in terms of their contribution to kinesthesia, the senses of position and movement of the limbs. It is argued that muscle spindles are not well suited as position sensors, on several grounds. Yet we know from muscle vibration experiments that they do contribute to kinesthesia. A number of recent experiments have shown that positional information is of particular significance to the central nervous system. In other experiments it has been demonstrated that a disturbance to kinesthesia follows fatigue from exercise. Fatigue of elbow flexor muscles led subjects to make significant positional errors in a forearm matching task. The size of the errors correlated with the fall in force from fatigue. These data suggest that we derive a positional cue from the effort required to hold a limb against the force of gravity. A challenge for the future will be to reveal how the centrally derived sense of effort and peripherally derived afferent information interact to give us our kinesthetic sense.     

What is the role of the cerebellum in the pathophysiology of dystonia?

Journal of Neurology -     

What is the role of procedural justice in civil commitment?

OBJECTIVE: To determine best practice management strategies in the clinical application of civil commitment. METHOD: All relevant literature on the topics of 'civil commitment', 'coercion' and 'procedural justice' were located on MEDLINE and PsychLIT databases and reviewed. Literature on the use of Ulysses contracts and advance directives in mental health treatment was integrated into the findings. RESULTS: Best practice evidence that guides management strategies is limited to the time of enactment of civil commitment. Management strategies involve enhancing the principles of procedural justice as a means of limiting negative patient perception of commitment. In the absence of evidence-based research beyond this point of enactment, grounds for the application of the principles of procedural justice are supported by reference to ethical considerations. Ulysses contracts provide an additional method for strengthening procedural justice. CONCLUSIONS: Procedural justice principles should be routinely applied throughout the processes of civil commitment in order to enhance longer term therapeutic outcomes and to blunt paternalism.     

The role of the hippocampus in long-term memory: is it memory store or comparator?

Several attempts have been made to reconcile a number of rival theories on the role of the hippocampus in long-term memory. Those attempts fail to explain the basic effects of the theories from the same point of view. We are reviewing the four major theories, and shall demonstrate, with the use of mathematical models of attention and memory, that only one theory is capable of reconciling all of them by explaining the basic effects of each theory in a unified fashion, without altogether sacrificing their individual contributions. The key issue here is whether or not a memory trace is ever stored in the hippocampus itself, and there is no reconciliation unless the answer to that question is that there is not. As a result of the reconciliation that we are proposing, there is a simple solution to several outstanding problems concerning the neurobiology of memory such as: consolidation and reconsolidation, persistency of long term memory, novelty detection, habituation, long-term potentiation, and the multifrequency oscillatory self-organization of the brain.     

Pathways of behavioural and emotional symptoms in kindergarten children: What is the role of pro-social behaviour?

The study investigated the predictive value of pro-social behaviour for developmental pathways of behavioural and emotional problems at kindergarten age. One hundred and sixty children participated in the study at the ages of 5 and 6. Teachers and parents completed the Strengths and Difficulties Questionnaire; children completed the Berkeley Puppet Interview at both assessment points. Single-informant data were aggregated to enhance the reliability and validity of data. Gender and parental educational status were controlled. Symptoms (conduct problems, hyperactivity and emotional symptoms) and pro-social behaviour were moderately stable over time. Compared to girls, boys showed higher levels and increases of conduct problems and hyperactivity and lower levels of pro-social behaviour. Lower parental educational level was associated with higher levels and increases in hyperactivity. Although pro-social behaviour was cross-sectionally associated with behavioural and emotional symptoms, pro-social behaviour did not predict changes in conduct problems or hyperactivity over time. However, children with above average emotional symptoms and above average pro-social behaviour at Age_5 showed the highest level of emotional symptoms at Age_6. The results indicate that low levels of pro-social behaviour are associated with children’s externalising behaviour problems, but that for children with high levels of emotional symptoms, higher levels of pro-social behaviour should also be considered as a risk factor. In sum, our results suggest mainly homotypic pathways of internalising and externalising symptoms across kindergarten age, but indicate that the assessment of pro-social behaviour yields additional information regarding the developmental pathways of emotional symptoms. The study was conducted at the Department of Child and Adolescent Psychiatry, University of Basel (Switzerland). The study was supported by the Swiss National Science Foundation (grant 32-66778.01), ‘Freie Akademische Gesellschaft Basel’ and ‘Novartis-Stiftung’.     

Effects of exercise on neurogenesis in the dentate gyrus and ability of learning and memory after hippocampus lesion in adult rats

Objective To explore the effects of exercise on dentate gyrus (DG) neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Methods Hippocampus lesion was produced by intrahippocampal microinjection of kainic acid (KA). Bromodeoxyuridine (BrdU) was used to label dividing cells. Y maze test was used to evaluate the ability of learning and memory. Exercise was conducted in the form of forced running in a motor-driven running wheel. The speed of wheel revolution was regulated at 3 kinds of intensity: lightly running, moderately running, or heavily running. Results Hippocampus lesion could increase the number of BrdU-labeled DG cells, moderately running after lesion could further enhance the number of BrdU-labeled cells and decrease the error number (EN) in Y maze test, while neither lightly running, nor heavily running had such effects. There was a negative correlation between the number of DG BrdU-labeled cells and the EN in the Y maze test after running. Conclusion Moderate exercise could enhance the DG neurogenesis and ameliorate the ability of learning and memory in hippocampus-lesioned rats.