Motor coordination

Motor coordination is most commonly assessed using a rotarod [16,17]. Rats or mice are placed onto a rod rotating either at a fixed speed or at a constantly increasing speed. The time taken for the animal to fall off the 

In contrast to most of the other core battery tests, the rotarod is unidirectional, detecting only the capacity of substances to decrease neuromuscular coordination. On the other hand, when used in conjunction with locomotor achvity tests, it provides a useful quantification of the margin of safety between doses of test substances that alter spontaneous activity and those that disturb motor function. 

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Ethanol is classified for medical purposes as a central nervous system (CNS) depressant. Its effects—that is, being drunk—resemble the human response to anesthetics. There is an initial excitability and increase in sociable behavior, but this results from depression of inhibition rather than from stimulation. At a blood alcohol concentration of 0.1% to 0.3%, motor coordination is affected, accompanied by loss of balance, slurred speech, and amnesia. When blood alcohol concentration rises to 0.3% to 0.4%, nausea and loss of consciousness occur. Above 0.6%, spontaneous respiration and cardiovascular regulation are affected, ultimately leading to death. The LD50 of ethanol is 10.6 g/kg (Chapter 1 Focus On). 

Finally, the cerebellum has recently become a focus of interest in the context of the pathophysiology of ADHD and as a possible target for psychostimulants since it is not only important for motor coordination but also for processing cognitive situations. 

There are similarities between the biological actions of inhalants and those of alcohol and barbiturates (Bowen et al. 1996b). For example, acute administration of inhalants affects motor coordination (Moser and Balster 1981) and induces anxiolysis, whereas chronic administration is associated with physical dependence and withdrawal (Bowen et al. 1996a Evans and Balster 1991, 1993). In addition, some inhalant drugs have anticonvulsant properties (Wood et al. 1984). Like other CNS-depressant agents, inhalants have biphasic effects on spontaneous locomotor activity in rodents, with increased activity seen at lower doses and diminished locomotion seen at higher doses (Cause et al. 1985 Kjellstrand et al. 1985). 

Iversen (1991) stresses the need for some in vivo testing for neurotoxicity and emphasizes the value of sensitive behavioral tests. Behavioral tests are described for mice and rats, which provide measures of mood, posture, CNS excitation, motor coordination, sedation, exploration, responsiveness, learning, and memory function. Such assays can function as primary screens for neurotoxicity before adopting a stepwise scheme of in vitro tests to discover more about the initial site of action of neurotoxic compounds. It is argued that the requirement for animal testing can be drastically reduced by adopting structured in vitro protocols such as these. 

Effects noted from exposures of 2-2.5 hours at 1,000 ppm include impaired visual-motor coordination (measured by groove-type hand steadiness, depth perception, and pegboard tests) (Vernon and Ferguson 1969) and, at 200 ppm, an increase in heart and breathing rates when trichloroethylene was inhaled simultaneously with ethanol ingestion (Windemuller and Ettema 1978). This latter study found no effect without ethanol ingestion. An 8-hour exposure (two 4-hour exposures separated by 1.5 hours) to 110 ppm... 

Additional in vivo studies on the biological activity of proanthocyani-dins investigating a series of behavioral activities (motihty, body weight gain, body temperature, motoric coordination, anticonvulsant effects and central analgesic activities) showed no or only moderate pharmacological effects [53]. On the other hand, dietary supplementation with cocoa pro-cyanidin supplements can dose-dependently prevent the development of hyperglycemia in diabetic obese mice [54]. 

The involvement of the cerebellum in the psychoactive effects of marijuana and in changes in rCMR is consistent with the view that THC interacts with the high concentration of CB1 receptors in this brain area. Decreases in the cerebellar rCMR in habitual marijuana users may reflect the effects of chronic exposure to the drug. Functions known to be associated with the cerebellum, such as motor coordination, proprioception, and learning, are adversely affected both during acute marijuana intoxication and in habitual users. 

Estradiol also induces synapses in the hippocampus and this contributes to enhanced capacity for learning and memory that is dependent on the hippocampus [13]. Estradiol exerts many other nonreproductive actions on the brain, such as fine motor coordination, seizure susceptibility, mood, protection from ischemic damage. Many of these actions occur in brain regions that show little, if any, nuclear estrogen receptors, and it seems likely that the nongenomic estrogen receptor described above may be involved [13]. 

After 21 days, reduced growth rate, impaired motor coordination of head and neck, and reduced ability to manipulate fish prey LD50 at day 17 postinjection LD100 at day 17 postinjection... 

Significant impairment of motor coordination and loss of good judgment Speech can be slurred balance, vision, reaction time, and hearing impaired. Euphoria. It is illegal to operate a motor vehicle at this level of intoxication. 

Scheduled and controlled operant responses as learning and memory tests were examined with several pyrethroids, and the data showed that pyrethroids produced dose-related decreases of operant response rates [34-36]. However, interpretation of these data may be difficult due to their dependence upon the integrated performance of several neurobiological systems (e.g., motor coordination, sensory response, and crossmodal association) [21]. 

When atmospheric oxygen content is lowered below 17 percent a person s motor coordination will be impaired. Below 10 percent, they will become unconscious. 

Motor coordination Time spend on the rotarod Rotarod Rat Chapillon et al.193... 

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