Digiscan activity: automated measurement of thigmotactic and stereotypic behavior in rats

Visual measures of stereotypy, margin time (thigmotaxis or wall-hugging), and center time were correlated with automated measures using a revised 16 beam version of the Digiscan Animal Activity Monitor System. Rats were injected with d-amphetamine (1.25, 2.5, 5.0 and 10.0 mg/kg), scopolamine (1.25 and 2.5 mg/kg) or saline and drugs were found to increase center time and decrease margin time in a dose-dependent manner, with the maximum effect occurring with 1.25 and 2.5 mg/kg, respectively. At higher doses, an opposite effect was observed. Extremely high correlations between visual and automated recordings of both margin time and center time were found. Since thigmotaxic or wall-hugging behavior has been used as an indicator of emotionality in rats, the results of the present study suggest that these two locomotor variables may be useful additions to the Digiscan multivariate analysis of locomotor behavior. It was also found that a redefinition of stereotypic behavior improved its correlation with visual measurements compared to earlier studies.