Motor pattern generators

Shannon R, Baekey DM, Morris KF, Lindsey BG (1998) Ventrolateral meduUary respiratory network and a model of cough motor pattern generation. J Appl Physiol 84 2020-2035 Shannon R, Baekey DM, Morris KF, Li Z, Lindsey BG (2000) Functional coimectivity among ventrolateral medullary respiratory neurones and responses during fictive cough in the cat. J Physiol 525 Pt 1 207-224... 

Fig. 144. The motor memory sets ( = motor pattern generators) of the cerebellum are toni-cally active even in the abscence of movement. They exert a tonic effect on other motor pattern generators in the vestibular and reticular nuclei and the motor cortex (via the thalamus)...

Jouvet s most radical and definitive experiments supported this idea. When he isolated the brain stem below the level of the junction of the two areas of the brain known as the pons and the midbrain and, even when he removed all of the brain above this level, he could still observe the periodic suppression of muscle tone, and occasional eye and body movements, including the rhythmic stepping that would be used in real locomotion by a normal cat during waking. In other words, one of the key formal features of human dreaming, the sense of continuous motion, may arise at the very low level of parts of the brain stem that generate motor patterns. In any case, such generators are present in the brain stem and are activated in REM. 

This constructive process, by which motor commands become the internal stimuli for sensory experience, is exactly what occurs in REM sleep dreaming when oculomotor and vestibular signals generate dream imagery. When this process was going on inside Huxley s head, Erickson observed changes in Huxley s head position and in his breathing pattern. 

The contribution of the various types of motor vehicles to the total line traffic-generated particulate matter was not quantified in this study. The traffic composition analysis indicated that petrol-driven passenger cars fitted with catalytic converters were the major contributor to traffic counts (about 60%). The daily traffic count ranged from 14,000 to 17,000 vehicles/h (15,500 1,200 vehicles/h). Results showed that traffic pattern on all days of a week had similar trend. Traffic count started to rise between 0700 and 1,300 h (mean 15,000 vehicles/h), before reaching maximum traffic count during 1,300-1,700 h (15,000-17,000 vehicles/h). Traffic counts then decreased between 1,700 and 2,000 h due to the diversion of vehicles towards other alternative routes as the Electronic Road Pricing (ERP)... 

Parnianpour, M., Nordin, M., and Kahanovitz, N. et al. 1988. The triaxial coupling of torque generation of trunk muscles during isometric exertions and the effect of fatiguing isoinertial movements on the motor output and movement patterns. Spine 13 982. 

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