Neuromuscular coordination

Mouse (Hybrid) Gd 1-18 1 x/d (F) 0.18 (neuromuscular coordination deficits, reduced litter size, delayed Spyker and Avery 1977... 

The present Section describes basic protocols satisfying ICH S7A recommendations for core battery CNS studies. Included are protocols for measuring general behavioral signs induced by test substances (Irwin Test), effects on spontaneous locomotion (Activity Meter Test), effects on neuromuscular coordination (Rotarod Test), effects on the convulsive threshold (Electroconvulsive Shock (ECS) Threshold and PTZ Seizure Tests), interaction with hypnotics (Barbital Interaction Test) and effects on the pain threshold (Hot Plate Test). 

Locomotor coordination is most commonly assessed using a rotarod (Dunham and Miya 1957). The rotarod consists of a circular rod turning at a constant or increasing speed. Animals placed on the rod will naturally try to remain on the rod rather than fall onto a platform some 30 cm below. This test therefore provides an estimate of the animal s level of neuromuscular coordination. Drugs which are known to perturb neuromuscular coordination (e.g. benzodiazepines) clearly reduce the time the animals stay on the rod. 

The rotarod test is one of the oldest used in the behavioral assessment of drug action. It provides a simple first estimation of whether a test substance has any effect on neuromuscular coordination and has been found sensitive to a variety of agents which are known to disturb it, for example the benzodiazepines. 

In contrast to most of the other core battery CNS tests, the rotarod is mainly unidirectional, detecting principally the capacity of substances to decrease neuromuscular coordination. This is not a serious limitation in that the risk factor evaluated is whether the test substance causes impairment. When used in conjunction with locomotor activity tests, the rotarod test provides a useful quantification of the margin of safety between doses of test substances which alter spontaneous activity and those which disturb motor function. 

The study of neuromuscular coordination in helminths would require under-... 

Although little is known about the neuromuscular system in helminth parasites, on the basis of the mammalian system the following classes of compounds may be envisaged to interfere with different states of the neuromuscular coordination. 

In addition to the various biochemical reactions operating during neuromuscular coordination, glucose metabolism and evasion of hosf s defences there are several other biochemical processes in the parasites which provide excellent targets for the design of effective anthelmintics. 

Neuromuscular decreased muscular coordination may be seen Castrointestinal/genitourinary dry mouth is common and urinary retention may occur in some persons... 

Decision/Solution. In addition to the neuromuscular facilitation activities, the physical therapist initiated a program of chest physical therapy including postural drainage and deep-breathing exercises. The physical therapist coordinated these activities with the respiratory therapist so that the patient first received a treatment of the mucolytic agent. Also, the physical therapist had the patient self-administer a dose of the inhaled beta-2 bronchodilator approximately 1 hour prior to the chest therapy session, thus allowing the bronchodilator to produce maximal airway dilation and permit optimal clearance of bronchial secretions. 

Neurobehavioral examinations are useful for identifying neurotoxicant-mediated deficits, but it is often difficult to localize the site of toxic action from such tests. For example, sensorimotor tests of reaction time, manual dexterity, hand-eye coordination, and finger tapping can indicate either neuromuscular or psychomotor damage. 

Some strains have difficulties balancing on an aluminum rod, and a more textured surface (e.g., wood) may help stabilize the animal. Increasing the diameter of the rod is another possible solution. If mice continue to struggle with balance or motor abilities, assess motor and vestibular functions separately as these behaviors may be due to a neuromuscular or motor coordination problem unrelated to vestibular deficits or anxiety. 

The fundamental cellular component of the nervous system, the neuron, has long, branching, cyllndrlc processes (dendrites and axon) that extend from the cell body. Dendrites are modified for signal reception and transduction and form extensive networks that permit Interneuronal communication, coordination, and integration of nervous-system function. The axon typically is a long extension of Che neuron specialized for transmission of electric signals and, at Its distal end, for chemical communication of Information to other neurons or to muscle at sites termed synapses and neuromuscular junctions, respectively. 

Intoxication with DDT results in ataxia, loss of coordination, convulsions, and hyperexcitation of insects and mammals. Various regions of the nervous system were stimulated to discharge repetitively either in response to a single stimulus or spontaneously. These included sensory cells, synapses, and nerve fibers (2.3.36.37). Repetitive after-discharges in nerve fibers were due to an increase in the depolarizing (negative) after-potential by DDT (M, 39). Repetitive responses in neuromuscular junctions have been shown to originate in presynaptic nerve terminals (40). It appears that DDT and pyrethroids exert similar effects on the nerve membrane sodium channel (41). Detailed analyses as described below clearly show that this is actually the case. 

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