Motor action

To detect a motoring action by a single-pole reverse power relay with a time setting of 2-10 seconds for... 

Figure 10.2. The motor homunculus produced by Penfleld and Rasmussen from direct stimulation studies. Note that the body is distorted and those areas which produce fine motor actions and manipulations (the hand and the mouth) are disproportionately represented.

Treseder, SA, Jackson, M and Jenner, P (2000) The effects of central aromatic amino acid (dopa) decarbosylase inhibition on the motor actions of L-dopa and dopamine agonists in MPTP-treated primates. Brit. J. Pharmacol. 129 1355-1366. 

Sanudo-Pena MC, Tsou K, Walker M. Motor actions of cannabinoids in the basal ganglia output nuclei. Life Sci 1999 65 703-713. 

Human 9.1 yr 69 (decreased MCV and motor action potential amplitude) Mutti et al. 1982a... 

The mammalian brain also possesses unifying anatomical circuits this circuitry appears to derive from the basic motor circuit. Motor systems, for example, unify diverse mofivafions and sensations fo drive singular purposeful actions. Anatomical circuifs underlying sleep-wakefulness, attention, and memory also unify varied inpufs info singular end sfafes. Consciousness, which is a unified sfafe, is likely fo be similarly driven by anatomical circuits such as those that drive motor actions, arousal, selective attention and memory. 

Stereotypies are repetitive motor actions that are similar to each other and represent the inability to initiate normal adaptive responses (Graybiel et ah,... 

Conceptually, tics are best seen as senseless habits that arise in response to a highly selective set of somatic and/or environmental cues. Habits, like tics, are assembled routines that link sensory cues with motor action. The neural substrates of habit formation and tics are neural loops that connect the basal ganglia with the cortex and thalamus (Fig. 13.1 Graybiel, 1998 Leck-man and Riddle, 2000). 

Deautomatization of motor actions is another sort of altered awareness of motor output that can occur in a d-ASC. Either you become unusually aware of components of automatized actions normally inaccessible to consciousness or you have deliberately to will each of these component actions to take place because the whole automated action will not occur by itself. 

Fig. 3. Schematic illustrations of distinct steps in cell division show the central role of contractile motor action in the process of mitosis. (A) to (C) replication (prophase) (D) formation of the mitotic spindle (metaphase) (E) and (F) chromosome migration (anaphase) and building of the nuclear envelopes, and (G) formation of the contractile ring containing actin and myosin, forming the cleavage furrow and eventually two separate daughter cells. CE, centriole pair A, aster of microtubules N, nucleus M, microtubules C, chromosomes K, kinetochore NR, remnant of nuclear envelope NE, nucelar envelope reforming CR, contractile ring CM, cell membrane]. From Squire (1986).

The present volume covers Muscle and Molecular Motors . The first few chapters describe the ultrastructures of striated muscles and of various muscle filaments (myosin, actin, titin), they discuss the regulation of muscle contractile activity, and they explore the mechanism of force production and movement. The book then sets out to survey other kinds of motor systems microtubules and their interactions with both microtubule associated proteins (MAPs) and the motor proteins kinesin and dynein, the major sperm protein in nematodes, the rotary ATPases driven by or driving proton gradients, and the action of motor enzymes, polymerases, on nucleic acids. The aim throughout is to explore different molecular mechanisms of motor action in order to identify common themes. 

In contractile experiments the time from the stimulation of the nerve to the CMAP recorded in muscle provides an estimate of NCV. The length of the nerve from the stimulating electrode to the muscle can simply be measured and divided by the time. However, the time recorded in this way includes the delay for synaptic transmission, which may be increased in models with synaptic defects. If this is a concern or if the only parameter desired is NCV, then the measurement can be obtained non-invasively with a relatively simple setup (e.g., (3)). Using the sciatic nerve, NCV can be calculated by measuring the latency of compound motor action potentials recorded in the muscle of a rear paw. Action potentials are produced by subcutaneous stimulation at two separate sites proximal stimulation at the sciatic notch and distally at the ankle. NCV is then calculated by using the two latencies and conduction distance. Decreases in nerve conduction velocity most often reflect defects in myelination, but may also be the result of changes in internodal distance, decreased axon diameters, or altered excitability. 

Gastrin pentapeptlde (l) in doses producing near maximal secretion of gastric acid (O.Ol mg./kg./min.) Increased motor activity of the antrum in man. 9 Hi er doses of pentapeptlde were needed to stimulate colonic activity in man.90 Gastrin II in doses of 25 or 50 [Xg. i.v. was found to increase motor action of the distal colon and rectum, however, the effect was more pronounced in the proximal portion of the alimentary tract.91 Doses used were 10 times the amount necessary to elicit acid secretion. 

The biogenic amine octopamine (OA) is widely recognized as an important neuroregulator in many invertebrates. It has been proposed as a neurotransmitter in the firefly light organ, and as a neuromodulator of muscle action and a neurohormone in the locust (J, 2). Octopamine also appears to act on central nervous system (CNS) sites affecting coordinated motor actions (3,4), and has been shown to modulate CNS thresholds for feeding in blowflies (5), and olfaction in honeybees (6). 

During my first experience with a psychedelic drug, mescaline, I told my body to walk down to the end of the hall. Then my awareness became completely absorbed in various internal events. After what seemed a very long time, I was surprised to notice that my body had walked down the hall and obligingly stopped at the end, with no conscious participation or awareness on my part. To some extent this occurs in an ordinary d-SoC, especially with well-learned actions, but the effect can be much more striking in a d-ASC. We should distinguish lack of sensory awareness of body actions from awareness of them but without the sense of ego added. The latter also creates a different relationship with motor actions. 

Several events must occur when a motor action is performed. The acting subject develops the intention to reach a goal by motor action. A motor plan is made. The orientation of the body is adapted to the spatial position of the goal and finally, the motor system must coordinate the activities of the different descending pathways. Before efferent motor actions can be started, sensoric afferent information about body and goal position in space must be established so that the motor system is able to estimate the consequences of actions. 

It is not quite clear how much these alterations contribute to the cognitive slowing and affective alterations in PD patients because, in contrast to the undoubted improvement of motor actions after... 

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