Psychomotor retardation in depression: bradykinesia or paucity of movement?

Objectives: Psychomotor retardation is part of Major Depression (MD) diagnosis criteria and has been assimilated to bradykinesia, even though there is a clear lack of objective measurement of motor activity in MD. We conducted a study to evaluate bradykinesia, posture and gait parameters in MD patients with an ambulatory system, allowing continuous motor measurements. Methods: Patients with DSM-IV MD and healthy controls matched for age and sex were asked to carry on with their usual activities while being recorded for 6 hours by a wireless autonomous ambulatory system, containing miniature gyroscopes, data-logger, battery and flash memory. allowing continuous recording of upper limbs movements (speed, amplitude and activity (% of time with movement)), posture (% of time standing, walking, lying or sitting) and gait parameters (speed, cadence, stance, double support, stride). Results: Hands activity was significantly lower in depressed patients, as compared to controls (MD: 40%, controls: 60%; p<0.05). Speed of hand movements (p= 0.13) and their amplitude (p=0.71) were similar to controls. MD patients had a trend to spend more time lying or sitting than controls (p=0.06) but did not differ in terms of any gait parameters. Conclusion: Patients with MD displayed less hand movements than controls and tended to spend more time lying or sitting over 6 hours, but did not differ in terms of speed and amplitude of movement, nor in gait parameters. These results suggest that psychomotor retardation classically described in MD might be the expression of a paucity of movement rather than a bradykinesia as observed in parkinsonism and might involved different (nondopaminergic) mechanisms.

Remorin, a solanaceae protein resident in membrane rafts and plasmodesmata, impairs potato virus X movement.

Remorins (REMs) are proteins of unknown function specific to vascular plants. We have used imaging and biochemical approaches and in situ labeling to demonstrate that REM clusters at plasmodesmata and in approximately 70-nm membrane domains, similar to lipid rafts, in the cytosolic leaflet of the plasma membrane. From a manipulation of REM levels in transgenic tomato (Solanum lycopersicum) plants, we show that Potato virus X (PVX) movement is inversely related to REM accumulation. We show that REM can interact physically with the movement protein TRIPLE GENE BLOCK PROTEIN1 from PVX. Based on the localization of REM and its impact on virus macromolecular trafficking, we discuss the potential for lipid rafts to act as functional components in plasmodesmata and the plasma membrane.

Mouvements anormaux et accident vasculaire cérébral [Movement disorders in stroke]

Dyskinesias are infrequent presentations in acute stroke (1%). They can be found more frequently as delayed presentations after a stroke, but the prevalence is not available from the literature. The full spectrum of hyper- and hypo-akinetic syndromes has been described, but three main pictures are rather specific of an acute stroke: limb shaking, hemichorea-hemiballism and unilateral asterixis. Besides limb shaking, that seems to reflect a transient diffuse ischemia of the frontosubcortical motor pathway, lesions are described at all levels of the frontosubcortical motor circuit including the sensorimotor frontoparietal cortex, the striatum, the pallidum, the thalamic nuclei, the subthalamic nucleus, the substantia nigra, the cerebellum, the brainstem and their interconnecting pathways, as ischemic or hemorrhagic strokes. The preferentially late development of dyskinesia could reflect the return to a more ancestral motor control level, the most functional possible with the remaining configuration of structures, elaborated by brain plasticity after stroke.

Lake dwellers occupation gap in Lake Geneva (France-Switzerland) possibly explained by an earthquake-mass movement-tsunami event during Early Bronze Age

High-resolution seismic and sediment core data from the 'Grand Lac' basin of Lake Geneva reveal traces of repeated slope instabilities with one main slide-evolved mass-flow (minimum volume 0.13 km3) that originated from the northern lateral slope of the lake near the city of Lausanne. Radiocarbon dating of organic remains sampled from the top of the main deposit gives an age interval of 1865-1608 BC. This date coincides with the age interval for a mass movement event described in the 'Petit Lac' basin of Lake Geneva (1872-1622 BC). Because multiple mass movements took place at the same time in different parts of the lake, we consider the most likely trigger mechanism to be a strong earthquake (Mw 6) that occurred in the period between 1872 and 1608 BC. Based on numerical simulations, we show the major deposit near Lausanne would have generated a tsunami with local wave heights of up to 6 m. The combined effects of the earthquake and the following tsunami provide a possible explanation for a gap in lake dwellers occupation along the shores of Lake Geneva revealed by dendrochronological dating of two palafitte archaeological sites.

25 years of movement monitoring on the south peak of Turtle mountain: Understanding the hazard

En 1981, le gouvernement de l'Alberta a amélioré la surveillance de la pointe sud « South Peak » de la montagne Turtle, sur la frontière sud du glissement Frank de 1903. Le programme de surveillance vise à comprendre les taux de déformation des fissures larges et profondes sur « South Peak », et à prédire une seconde avalanche rocheuse sur la montagne. Le programme de surveillance consiste à installer un complément de points statiques et de stations suivies à distance, qui sont mesurés périodiquement. Des données climatiques, microsismiques et de déformation sont recueillies automatiquement à intervalles journaliers, et sont archivées. À la fin des années 1980, le financement pour le développement du programme de surveillance a cessé et quelques installations se sont détériorées. Entre mai 2004 et septembre 2006, des lectures sur les points de surveillance encore fonctionnels ont été compilées et interprétées. De plus, les lectures prélevées auparavant ont été réinterprétées à partir des connaissances récentes sur les modèles de mouvement à court terme et les influences climatiques. Ces observations ont été comparées à des récentes observations aériennes d'un modèle digital d'élévation, provenant de « light detection and ranging (LiDAR) », et des photos de terrain, afin d'estimer plus précisément les taux, l'étendue et la distribution des mouvements pour les derniers 25 ans.

Dimorphic turning bias in spontaneous rotational movement

Turning biases have been associated with unbalanced hemispheric dopaminergic activity, and this activity has been correlated with cue-directed behaviors. Moreover, a sexual differentiation in hippocampal dopaminergic receptors following learning has been shown. In humans, pointing responses towards the starting point is commonly used to assess the accuracy of direction estimation after locomotion. Thus, it may be of interest for the field of spatial cognition to explore human sex differences in spontaneous turning bias when a body rotation is required. To this end, male and female blindfolded subjects were guided in a linear displacement and asked to rotate in order to point in the direction of the starting position. The main finding was a massive difference between men and women. 80% of women showed a turning bias to the right when 69% of men showed a bias to the left. Moreover, these preferences were not correlated with handedness. These results suggest basic preferences associated to sex might influence male and female performance in spatial cognition. They also suggest experimental procedures may be biased in favor of male or female strategies. Therefore, such preferences should be considered in order to gain further insight into the development of more balanced procedures.

Measuring limits of telomere movement on nuclear envelope.

The dynamic behavior of the decondensed chromatin can be monitored by real-time fluorescence confocal microscopy. It can be observed that different chromosomal sites enjoy different degrees of freedom during a certain period, exploring larger or smaller portions of nuclear volume. Here we measure the accessible surface for two chromosomal sites (yeast telomeres Tel3R and Tel6R) that both exhibit strong preferential association with the nuclear membrane in galactose-containing media, but differ significantly in gene activity. Telomere Tel6R, which harbors an inducible gene with high levels of transcription, explores a much larger surface than the telomere Tel3R, which is adjacent to inactive chromatin. Thus, our results distinguish two perinuclear movements characteristic of different transcriptional state, allowing for a better understanding of the correlation between activity of genes and chromatin dynamics.

DBS in Dystonia and Other Hyperkinetic Movement Disorders.

OPINION STATEMENT: The diagnosis and appropriate treatment of hyperkinetic movement disorders require a work up of potentially reversible metabolic, infectious and structural disorders as well as side effects of current medication. In pharmacoresistant movement disorders with a disabling impact on quality of life, deep brain stimulation (DBS) should be considered. At different targets, DBS has become an established therapy for Parkinson's disease (GPi-STN), tremor (VIM) and primary dystonia (GPi) with reasonable perioperative risks and side effects, established guidelines and some clinical and radiological predictive factors. In contrast, for other hyperkinetic movement disorders, including secondary dystonia, Gilles de la Tourette, chorea and ballism, only few data are available. Definite targets are not well defined, and reported results are of less magnitude than those of the recognized indications. In this expanding therapeutical field without worked out recommendations, an individual approach is needed with DBS indication assessment only after rigorous multidisciplinary scrutiny, restricted to expert centres.