William P. Paré

STRESS AND CONSUMMATORY BEHAVIOR IN THE ALBINO RAT.

This study investigated the relationship between intense chronic stress and body weight changes. Variations in food and water consumption, urine volume, and BMR were also observed. Twelve rats were subjected to tone-shock pairings 20 hr. daily for 22 days. Twelve rats received only one shock; 12 rats received neither shock nor tone; and 12 rats served as home-cage controls. Animals subjected to the tone-shock condition manifested a significant body weight loss, an inhibition of food and water intake, and a reduced urine volume, as compared to other treatment groups. Prolonged intense stress is instrumental in initiating a loss in body weight due to inhibition of consummatory behavior which is concurrent with a significant anti-diuresis.

Relationship of Various Behaviors in the Open-Field Test of Emotionality

Using Halls open-field test of emotionality, measures of latency, ambulation, rearing, defecation, urination, and squealing were obtained from 126 male Sprague-Dawley rats for 4 daily sessions. Defecation correlated significantly only with urination. The hypothesis that defecation and ambulation are inversely related was not confirmed. Emotionality, in the rat, is best defined by amount of defecation in the open field.

EMOTIONAL BEHAVIOR AND ADRENAL FUNCTION IN THE RAT.

The relationship of open-field behaviors (latency, ambulation, rearing, and defecation) and adrenal weight and adrenal ascorbic acid (AAA) was investigated. 38 male Sprague-Dawley rats received one daily trial in the open field for 4 days. Measures of adrenal weight and AAA were subsequently obtained. Correlations between variables indicated no meaningful relationship between emotional defecation and adrenal responses. Rearing correlated significantly with AAA. Latency was significantly related with adrenal weight. These results are consistent with recent studies investigating performance of emotional Ss on escape-avoidance conditioning and CER behavior.

The effect of conflict and shock stress on stomach ulceration in the rat

Abstract Data on stomach condition and adrenal weight are presented which indicated that animals subjected to shock stress experienced are more stressful environment as compared to Ss subjected to an approach-avoidance (water shock) conflict. Ulcers previously reported as having been developed by psychological stress may be attributed, to a greater degree, to the physical stress of electric shock.

The effect of insular neocortical lesions on passive and active avoidance behavior in the rat

Rats with insular lesions were deficient in adopting a passive-avoidance response. However, Ss with insular lesions did not differ from operated and normal control Ss in the acquisition of an active-avoidance response.

Information processing in preschool children

Preschool children between the ages of 3 and 5 were asked to tell E whether the two figures on a stimulus card were “exactly the same, or different.” The stimulus cards were classified into seven levels of complexity, based upon the number of “bits each figure contained.” It was found that the 3, 4, and 5-yr. old Ss performed better than chance at successively higher levels of complexity.

Modification of Emotionality in the Rat as a Function of Prolonged Shock Stress

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 Malmos activation theory.