Using biotelemetry for integrated measurement of behavior and physiology in laboratory animals
W. Tornatzky and K.A. Miczek
Department of Psychology, Tufts University, Medford, MA, U.S.A.
 
Hyperthermia, tachycardia and hypertension are essential components of the stress response in humans and animals. A series of projects will delineate how the analysis of the acute and long-term responses to stress may benefit from concurrently recorded behavioral and physiological variables. The heart rate (HR), blood pressure and core temperature (Tc) of rats were measured by radio-telemetry for up to 6 months and the behavior of the resident and the intruder rats was evaluated from video records taken during the social confrontations. A drug-induced lessening of the stress could in this way be characterized by a change in the response profile that was composed of the animal's resting, locomotor, exploratory, defensive behavior, the ultrasonic vocalizations and its reactive or anticipatory autonomic reactivity. The dose-dependent anxiolytic or anxiogenic drug effects on the behavior of the rat intruding in the home cage of the resident were coordinated with the intruder's autonomic stress responses. The second set of data will compare autonomic and behavioral changes induced by self-administration of cocaine. Using operant conditioning procedures rats were trained to self-administer cocaine via the intra-venous route. Repeated, limited access to cocaine was found to synchronize HR and Tc rhythms in anticipation of these self-administration sessions that were scheduled daily at the same time, whereas prolonged unlimited access disrupted biological rhythms.
The analysis of individual differences in responses to stress stimuli profits of a comprehensive behavioral analysis supplemented by the concurrent evaluation of autonomic changes. Combined with a repeated measurement design this research strategy reduces the number of animals needed to make a valid statement about treatment effects.
Paper presented at Measuring Behavior '98, 2nd International Conference on Methods and Techniques in Behavioral Research, 18-21 August 1998, Groningen, The Netherlands
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