Righting reflex

Beagle) Ix/d (F) and optical stimuli muscle spasms in extremeties, face, and jaw placing and righting reflexes absent) Technical... 

Rotarod, Righting Reflex, Convulsant Activity, and Lethality... 

FIGURE 6. Histograms depicting doses of PCP and related compounds which produced (A) maximal disruption of rotarod performance (B) loss of righting reflex (C) clonic and/or toxic convulsions and (D) lethality in rats (n=6) given cumulative intravenous doses... 

Rat (CD) 201-291 d ad lib 0.7 3.5 (delays in vaginal opening in pups) 7 (delayed righting reflex in pups) Grant etal. 1980... 

Delays in the development of the righting reflex were observed by Reiter et al. (1975) in rat pups whose dams were exposed to lead acetate at concentrations of 0.7 and 7 mg lead/kg/day in their drinking water throughout gestation and lactation. Eye opening was delayed at the higher exposure level. Blood lead levels were not determined. 

At 280,000 ppm, there was a loss of righting reflex within 10 min (10-min EC50) (Collins 1984). Rats exposed at 205,000 ppm were lethargic and developed tachypnea (Silber and Kennedy 1979a). At 359,300 ppm, trembling and tearing also occurred. No effect was observed after a similar exposure at 81,000 ppm. At 300,000 ppm, anesthesia of rats occurred in less than 2 min (Ritchie et al. 2001). During 15-min exposures at... 

The EC50 for anesthesia (measured by the loss of righting reflex) was... 

A single test will be used to determine acceptance or rejection of a test material. Once an activity criterion (such as an X score in a righting reflex test) is established, compounds are evaluated based on being less than X (i.e., negative) or equal to or greater than X (i.e., positive). As more data are accumulated, the criterion should be... 

If we collect a set of control data on a variable (say scores on our observations of the righting reflex) from some number of ordinary animals, we can plot it as a set of two histograms (one for individual animals and the second for the highest total score in each randomly assigned group of five animals), such as those shown in Figure 4.4 (the data for which came from 200 actual control animals). 

Figure 4.4. Plotting central tendency. Possible individual scores for righting reflexes may range from 0 to 8 (Gad, 1982a). Group total scores would thus range from 0 to 40. (Shown are the number of groups that contain individual scores in the individual categories.)...

SC-35135 (PO) Arrhythmias Reduced motor activity, lost righting reflex, tremors, dyspnea, ataxia, mydriasis... 

SC-32840 (PO) Intravascular thrombosis Reduced motor activity, ataxia, lost righting reflex, closed eyes, red/clear tears... 

Lost Righting Reflex Animal Code for Recording Observations... 

The absence of or reduced response to external stimuli, accompanied with a loss of righting reflex. 

In animal studies acetone has been found to potentiate the toxicity of other solvents by altering their metabolism through induction of microsomal enzymes, particularly cytochrome P-450. Reported effects include enhancement of the ethanol-induced loss of righting reflex in mice by reduction of the elimination rate of ethanol increased hepatotoxicity of compounds such as carbon tetrachloride and trichloroethylene in the rat potentiation of acrylonitrile toxicity by altering the rate at which it is metabolized to cyanide and potentiation of the neurotoxicity of -hexane by altering the toxicokinetics of its 2,4-hexane-dione metabolite.Because occupationally exposed workers are most often exposed to a mixmre of solvents, use of the rule of additivity may underestimate the effect of combined exposures. ... 

Male mice exposed for 20 minutes to up to 4000 ppm showed changes in posture, decreased arousal, increased tonic/clonic movements, disturbances in gait, delayed righting reflexes, and increased sensorimotor reactivity. On removal from exposure recovery was rapid. 

Mice lost their righting reflex at approximately 9000ppm, and 15,000ppm was lethal. ... 

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