Measurement of rodent stereotyped behavior.

This unit presents a quantitative, observational method for the assessment of rodent stereotyped behavior which consists of motor responses that are repetitive, invariant, and seemingly without purpose or goal. The most classic behavioral pattern that is characteristic of stereotypy is that elicited by high doses of stimulants, such as cocaine and amphetamine, in rats, although it can also occur in response to other drugs or neurotoxic treatments affecting the basal ganglia. An observational time-sampling procedure is described in which animals are observed and rated by an experimenter, who is blind to treatment, at regular time points over the course of a behavioral testing period. The frequency of different behaviors is measured by scoring the presence or absence of a given behavior during predetermined time bins. The apparatus and test procedures are described, and a comprehensive list of commonly observed behaviors that may appear as stereotyped is provided. In addition to being ideally suited to the measurement of stereotypy, the protocol can be adapted to sampling many forms of spontaneous behaviors, including locomotion, rearing, grooming, eating, and drinking. Samples of behavioral checklists and scoring sheets are also provided.