Abstract
In order to investigate the effect of chronic stress on open-field behavior in adult organisms, 24 male, 95-day-old rats, equated with 24 control Ss, were subjected to tone-shock stress 20 hr. daily for 26 days. Open-field responses of latency, ambulation, rearing and emotional elimination (EE) were obtained on 4 subsequent open-field trials. In addition to a significant adrenal hypertrophy, chronic stress produced a significant decrease in latency, and an increase in ambulation and rearing scores for experimental Ss. Conclusions are: (a) latency, ambulation, rearing, and EE are not equally valid indices of emotionality in the rat; (b) 26-day stress does not modify adult emotionality as defined by EE. Results are discussed in terms of adaptation and Malmo's activation theory.
