Righting vs. Negative Geotaxis: A Methodological Evaluation

摘要

The purpose of this study was to compare the inherent variability of the righting reflex and negative geotaxic response. The righting reflex was tested on days 1-6, and the time to right was recorded for each pup on each of 3 trials. The negative geotaxic response was evaluated on a 25 degree sandpaper-covered incline on days 6-9. Behavior on the incline and time required to successfully turn 180 degrees were recorded for each pup on each of 3 trials. The results of the righting reflex measure indicated that the latency data should be analyzed based on litter means, and that one trial/animal is sufficient. Based on the large sample size needed and the low test-retest reliability, the righting reflex response is not recommended for use in studies aimed at the detection of treatment effects. The negative geotaxis data suggest that when the negative geotaxic response is measured, the latency data should be analyzed based on litter means. Based on the reliability of this response pattern both within and across animals and on feasible sample size requirements, the measurement of the negative geotaxic response appears to be a good early neuromotor test for application in studies of developmental toxicity.