Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

50 right-handed men were evaluated on right and left hand-grip strength, fatigue, and perseveration tasks and on a finger-tapping task. Subjects were tested in combined ambient sensory conditions of bright light and noise, bright light and quiet, dim light and noise, and dim light and quiet to provide an initial test of asymmetrical activation of the hemispheres. Analysis did not support the hypothesized asymmetry in activation. However, increased fatigue and perseveration were found using the left hand.
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PMID:Manual dexterity, strength, fatigue, and perseveration: an initial test of asymmetry in cerebral activation. 237 6

Rats treated with scopolamine (0.5 mg/kg SC daily) during the acquisition of a discrimination task with symmetrical negative reinforcement (light-go, noise/light-no go) showed a learning impairment, with both active and passive avoidance deficits. In the initial stage of such training, however, fewer passive avoidance errors and more active avoidance errors were made by treated animals if active avoidance pretraining had occurred in the no-drug state. A similar experiment using the same stimulus arrangement with asymmetrical reinforcement (no punishment of intertrial, and no go signal, responses) showed a scopolamine effect consisting mainly of increased responding to extinction signals and during intertrial intervals, with little or no active avoidance deficit. Furthermore, interactions due to changes in treatment conditions in successive stages of training were minimized in the latter task, suggesting that the effects of the shift-no shift factor on distribution of errors in the early stages of active-passive avoidance learning were unlikely to have been due to a genuine drug dissociation. Overall, these results and others obtained previously in the same and related tasks tend to rule out some unidimensional explanations of antimuscarinic effects, e.g., response disinhibition (an exclusively motor deficit) or impairment of stimulus sensitivity (an exclusively sensory deficit). The data rather confirm the notion of a sensorimotor drug bias leading to a shift in response prepotencies depending jointly on stimuli, responses, and response consequences. Prior learning history and behavioural compensation for adverse treatment consequences at the reinforcement level may interact with the sensorimotor bias so as to produce "set perseveration" (perseveration of response tendencies).
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PMID:Scopolamine and acquisition of go-no go avoidance: a further analysis of the perseverative antimuscarinic deficit. 641 Apr 41

The effects of combinations of bright or dim light and noise levels on hand strength, fatigue, motor perseveration, and tapping rate were evaluated in 13 undergraduate and 13 elderly females. Increments in the intensity of sensory conditions produced opposite effects on grip strength at the left, as opposed to the right hand. Reliable asymmetry in hand strength (right > left) was observed in bright but not dim lighting in the younger group. In the elderly group, the extent of asymmetrical hand strength was related to the combination of light and noise intensity. Data suggest that increments in sensory conditions may differentially activate the cerebral hemispheres of the elderly and younger groups affecting grip strength. Results are discussed in relation to the hemiaging hypothesis.
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PMID:Age differences in hemispheric activation to sensory condition. 900 85

We describe four patients who developed asymmetrical, rhythmic, stereotyped, and repetitive movements of the upper and lower limbs hours to days after infarction that involved the thalamus and/or basal ganglia. The movements appeared to occur spontaneously and were initially labeled as focal motor seizures, ballism, or tremor; they could however, be induced by passive movement of the limbs. The movements most commonly observed were scratching or rubbing movements of the hands that were of such persistence as to cause trauma to the skin; in the lower limbs, the heel was run up and down the bed sheet, often until it bled. The movements were part of a syndrome characterised initially by a reduced level of consciousness and followed by aspontaneity, usually with mutism and frontal release signs. One patient who had relatively preserved cognition and language repeated words or phrases again and again when encouraged to speak, but had no difficulty changing responses appropriately to different cues. In drawing, he overwrote each figure but could change the figure on command. The distinctive movement disorder in these patients was due to clonic perseveration. We suggest that clonic perseveration results from disconnection of prefrontal cortico-basal ganglia-thalamo-cortical loops that are important for the termination of motor plans. Clonic perseveration should be recognised as a movement disorder following thalamic lesions.
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PMID:Clonic perseveration following thalamofrontal disconnection: a distinctive movement disorder. 915 33

Callosal disconnection can reveal asymmetrical contributions of the two brain hemispheres to praxis. In this paper, we revisit a study of a patient with callosal disconnection (Goldenberg et al., 2001, Neuropsychologia, 39:1432-1443), who perfectly imitated meaningless gestures when imitation was controlled only by the left hemisphere, but was severely impaired when the right hemisphere was in charge of motor control. We decomposed the gestures into a set of geometric variables that were to be reproduced, such as the orientation of the hand and the position of contact between the hand and the face. Whereas orientation of the hand in extrinsic coordinates was replicated correctly by both hemispheres, only the left hemisphere reproduced correctly the position of contact between the hand and the face. This goal-dissociation as well as several partial perseveration errors speak against the hypothesis of a direct route from perception to motor replication of gestures, as interruption of a direct route would probably impair all the features of the gesture. We speculate that incorrect coordination between the reproductions of multiple goals may be the core deficit underlying callosal apraxia.
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PMID:Revisiting a study of callosal apraxia: the right hemisphere can imitate the orientation but not the position of the hand. 2043 50