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[Motor functions of the dominant hemisphere for speech].
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Interrelationships among perceptual-motor functions in children.
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Selective spatial localization of actomyosin motor function by chemical surface patterning.
We have previously described the efficient guidance and unidirectional sliding of actin filaments along nanosized tracks with adsorbed heavy meromyosin (HMM; myosin II motor fragment). In those experiments, the tracks were functionalized with trimethylchlorosilane (TMCS) by chemical vapor deposition (CVD) and surrounded by hydrophilic areas. Here we first show, using in vitro motility assays on nonpatterned and micropatterned surfaces, that the quality of HMM function on CVD-TMCS is equivalent to that on standard nitrocellulose substrates. We further examine the influences of physical properties of different surfaces (glass, SiO(2), and TMCS) and chemical properties of the buffer solution on motility. With the presence of methylcellulose in the assay solution, there was HMM-induced actin filament sliding on both glass/SiO(2) and on TMCS, but the velocity was higher on TMCS. This difference in velocity increased with decreasing contact angles of the glass and SiO(2) surfaces in the range of 20-67 degrees (advancing contact angles for water droplets). The corresponding contact angle of CVD-TMCS was 81 degrees. In the absence of methylcellulose, there was high-quality motility on TMCS but no motility on glass/SiO(2). This observation was independent of the contact angle of the glass/SiO(2) surfaces and of HMM incubation concentrations (30-150 microg mL(-)(1)) and ionic strengths of the assay solution (20-50 mM). Complete motility selectivity between TMCS and SiO(2) was observed for both nonpatterned and for micro- and nanopatterned surfaces. Spectrophotometric analysis of HMM depletion during incubation, K/EDTA ATPase measurements, and total internal reflection fluorescence spectroscopy of HMM binding showed only minor differences in HMM surface densities between TMCS and SiO(2)/glass. Thus, the motility contrast between the two surface chemistries seems to be attributable to different modes of HMM binding with the hindrance of actin binding on SiO(2)/glass.
Cervical root repair in adult rats after transection: recovery of forelimb motor function.
Functional recovery was achieved in rats after repairing the transected left sixth and seventh cervical roots. Intercostal nerves were used for reanastomosis between the transected roots and the spinal cord, and acidic fibroblast growth factor with fibrin glue was applied. Experimental rats showed relevant functional recovery of gait and grooming reflexes. Electromyography demonstrated less denervation and more regeneration. Horseradish peroxidase retrograde axonal tracing disclosed a statistically significant increase of motor neuron survival, suggesting that motor neuron survival was significantly correlated with functional recovery. It is our belief that this novel treatment strategy may help patients with similar injuries in the future.
[Nature of functional motor asymmetry in animals: state of the problem].
Handedness in skilled movements of animals is a result of interaction of innate motor preference and learning. The nature of the innate preference is not clear. Breeding of right-handed and left-handed mice revealed that the degree rather than direction of motor preference is an inherited feature. There is, however, a correlation between the direction of preference and a number of morphological, functional, and neurochemical characters. Shifts of a preference direction were found in some strains of mice. Differences between right-handed and left-handed rats were revealed in social behavior, learning, and resistance to forced retraining. Strains of rats with different forms of genetic epilepsy were characterized by the predominance of animals with a certain direction of the motor preference. This evidence suggests some genetic influence on a direction of the motor preference. Perhaps, genetic and environmental factors closely interact in determining motor preference in animals.
Scintigraphic techniques for the study of gastrointestinal motor function.
A variety of scintigraphic techniques has been added to the gastroenterologist's armamentarium for the evaluation of motor dysfunction of the upper gastrointestinal tract and hepatobiliary tree. These methods include: esophageal transit scintigraphy for the measurement and quantitation of aboral movement of liquids through the esophagus, and for the measurement of esophageal clearance; gastroesophageal reflux scintigraphy for the detection and quantitation of gastroesophageal reflux, gastric scintigraphy for the physiological measurement of the simultaneous rates of emptying of liquids and solids from the stomach; hepatobiliary scintigraphy for the detection of acute cholecystitis, biliary tract obstruction, bile leaks; and enterogastric reflux scintigraphy for the detection and quantitation of bile reflux from the small bowel into the stomach. Each of these methods is relatively physiologic in comparison to other modalities in that none requires intubation or other nonphysiologic maneuvers. Each offers the practicing internist, surgeon, and gastrointestinal physiologist, the ability to measure normal and abnormal function in patients. Because of the low radiation burdens involved and high patient acceptance, these methods are suitable for serial studies in the same patient, particularly before and after the application of various therapeutic modalities.
Perceptual-motor function of school-age children with slow handwriting speed.
OBJECTIVES: This study investigated differences in perceptual-motor measures and sustained attention between children with slow and normal handwriting speed and the relationship between these factors. METHOD: Thirty-four slow handwriters and 35 normal speed handwriters (7 to 11 years of age) attending elementary schools in Taiwan were given three perceptual-motor tests and a vigilance task to assess sustained attention. Performances on these measures were analyzed using multivariate analysis of variance and regression analyses. RESULTS: A significant difference was found between slow and normal handwriters in upper-limb coordination, visual memory, spatial relation, form constancy, visual sequential memory, figure ground, visual-motor integration, and sustained attention. The three significant predictors of handwriting speed for the slow handwriters were age, visual sequential memory, and visual-motor integration. For the normal speed handwriters, age and upper-limb speed and dexterity were the only two significant predictors. CONCLUSIONS: Slow and normal speed handwriters responded to handwriting demands through different perceptual-motor systems. Whereas upper-limb speed and dexterity seems to play an important role in normal speed handwriters, slow handwriters seem to rely more on visually directed processes, including sequence memory and visual-motor integration.
[The quantitative assessment of spinal motor function during the action of hydrogen sulfide baths on patients with lumbar osteochondrosis].
300 males experiencing pain and motor dysfunction as a result of lumbar osteochondrosis received sulfide balneotherapy. The baths contained moderate (50-150 mg/l) and high concentrations (150-250 mg/l) of hydrogen sulfide. The effect of the treatment was assessed with repeated goniometry by means of specially devised instruments by 6 parameters. According to the degree measurements, the recovered motility in the lumbar spine in patients on large-concentration baths surpassed that in patients on less concentrated ones 1.5-fold.
Striatal and forebrain nuclei volumes: contribution to motor function and working memory deficits in alcoholism.
BACKGROUND: Striatal structures are involved in dopaminergic alcohol reward mechanisms and aspects of motor control. Basal forebrain structures hold cholinergic mechanisms influencing memory formation, vulnerable to chronic alcoholism; however, alcoholism's effect on volumes of these structures has seldom been considered with in vivo measurement. METHODS: We measured bilateral volumes of caudate nucleus, putamen, nucleus accumbens, and medial septal/diagonal band (MS/DB) in 25 men with alcohol dependence and 51 age-matched control men. Six alcoholic subjects had been drinking recently, and 19 had been sober. RESULTS: Volumes of caudate and putamen were smaller in the alcoholics than in the control subjects, regardless of length of sobriety. Recent drinkers showed greater deficits in nucleus accumbens than sober alcoholics. Putamen volume was positively correlated with grip strength; MS/DB volume was positively correlated with verbal working memory independently of the negative association between age-standardized MS/DB and age in alcoholics. CONCLUSIONS: Caudate and putamen volume deficits occur and endure in chronic alcoholism. Nucleus accumbens might be especially sensitive to recent alcohol exposure. Striatal volumes should be considered in functional imaging studies of alcohol craving that target striatal brain regions. The age-alcohol interaction for MS/DB volumes is consistent with a cholinergic mechanism for the working memory impairment observed in the alcoholics.
The good side after stroke: ipsilateral sensory-motor function needs careful assessment.
Twenty subjects were examined 4-6 weeks after stroke to establish whether a sensory-motor ipsilateral deficit occurs early after stroke. Each underwent a timed test of repetitive side-to-side movement of both the upper and lower limbs ipsilateral to the cerebral infarct, and an assessment of motor disability using the Motor Assessment Scale. Results were compared with a group studied almost a year after their stroke, and with 41 age-matched healthy volunteers. There was a significantly worse performance (p < 0.005) on the right ipsilateral side, but not the left ipsilateral side, compared with normal volunteers, a finding similar to that of a group previously studied about a year after the stroke. There was no relationship between the severity of the motor deficit and performance of the side, possibly owing to reduction in cerebral activation as a result of a right hemispheric lesion. These observations have importance in rehabilitation and education as well as practical skills, including driving a car and maintaining balance.
Modulation of motor function and cortical plasticity in health and disease.
Basic science studies demonstrated mechanisms of plasticity and metaplasticity. More recent human studies identified some of these mechanisms as operating in multiple areas of human cognition, such as learning and memory, and in functional recovery from lesions in the CNS, as in stroke. One of the goals of neurorehabilitation is the translation of these principles into rational strategies to promote recovery of function. Understanding the mechanisms and functional role of human plasticity could lead to the development of therapeutic options in situations in which there is virtually no treatment alternative, as in chronic stroke. We review some of the work performed to better understand the substrates and mechanisms underlying cortical plasticity and discuss some experimental approaches to enhance cortical plasticity and recovery of function, like cortical stimulation.
Which motor disorder in Parkinson's disease indicates the true motor function of the basal ganglia?
Parkinson's disease in its earlier stages is argued to be the best available model for human basal ganglia dysfunction. The negative motor symptoms of Parkinson's disease are considered to give the greatest clue to normal function of this region of the brain. Particular attention is given to disorders of movement. These include delayed initiation and slowed execution of simple fast movements, due to abnormal specification of initial agonist activity. This might compromise predictive motor action, but this is shown to be preserved in Parkinson's disease. Disorders of more complex movements, such as repetitive, concurrent and sequential motor actions, are also abnormal in Parkinson's disease. These various defects are discussed in terms of a motor strategy involving the selection and sequencing of motor programmes to form a motor plan, and the initiation and execution of that motor plan. On the evidence available, it is suggested that patients with Parkinson's disease are unable to automatically execute learnt motor plans.
Involvement of endogenous CCK and CCK1 receptors in colonic motor function.
Cholecystokinin (CCK) is a brain-gut peptide; it functions both as a neuropeptide and as a gut hormone. Although the pancreas and the gallbladder were long thought to be the principal peripheral targets of CCK, CCK receptors are found throughout the gut. It is likely that CCK has a physiological role not only in the stimulation of pancreatic and biliary secretions but also in the regulation of gastrointestinal motility. The motor effects of CCK include postprandial inhibition of gastric emptying and inhibition of colonic transit. It is now evident that at least two different receptors, CCK(1) and CCK(2) (formerly CCK-A and CCK-B, respectively), mediate the actions of CCK. Both localization and functional studies suggest that the motor effects of CCK are mediated by CCK(1) receptors in humans. Since CCK is involved in sensory and motor responses to distension in the intestinal tract, it may contribute to the symptoms of constipation, bloating and abdominal pain that are often characteristic of functional gastrointestinal disorders in general and irritable bowel syndrome (IBS), in particular. CCK(1) receptor antagonists are therefore currently under development for the treatment of constipation-predominant IBS. Clinical studies suggest that CCK(1) receptor antagonists are effective facilitators of gastric emptying and inhibitors of gallbladder contraction and can accelerate colonic transit time in healthy volunteers and patients with IBS. These drugs are therefore potentially of great value in the treatment of motility disorders such as constipation and constipation-predominant IBS.
Brain-machine interfaces to restore motor function and probe neural circuits.
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Motor function of basal ganglia.
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[J.M. Charcot and the discovery of the site of motor function in the human].
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[The status of the motor function in chronic exposure to radiation].
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