M. Van Den Buuse et al., Blood pressure, heart rate, and behavioral responses to psychological "novelty" stress in freely moving rats, PSYCHOPHYSL, 38(3), 2001, pp. 490-499
We developed a new model of psychological "open-field" stress in freely mov
ing rats. Blood pressure and heart rate of. the rats were measured by radio
telemetry and behavior analyzed by video tracking software. Open-field expo
sure induced marked increases in blood pressure and heart rate. Repeated da
ily exposure induced pressor responses that were slightly higher on Day 4 w
hen compared to Day 1. Pretreatment with the beta1-adrenoceptor antagonist
atenolol inhibited the tachycardia whereas the ganglion blocker pentolinium
inhibited the presser response, indicating involvement of the sympathetic
nervous system. Pretreatment with diazepam prevented the novelty stress-ind
uced presser response and reduced the tachycardia. These results show that
the psychological stress of exposing rats to an open field induces marked c
ardiovascular effects that are mediated by sympathetic hyperactivity. This
model is unique in that it focuses on psychological stress and allows conco
mitant measurement of blood pressure. heart rate, and behavior in freely mo
ving rats.