Omission training and extinction in rats with septal damage.

Rats with either control operations or septal damage were pretrained on a VI 30-sec schedule and tested for response suppression ability on either an omission training (OT) task or on extinction. Septal damage enhanced barpressing on the VI 30-sec task. Animals with septal damage took longer to suppress responding on the OT task than controls while lesioned and control animals tested on extinction did not differ. Increased emotionality was seen in subjects with septal damage on the first test day but not thereafter. Animals tested with OT suppressed responding more rapidly than animals tested on extinction.

Memory deficit in passive-avoidance learning in bulbectomized Long-Evans hooded rats.

Male and female Long-Evans hooded rats were subjected to either olfactory bulb damage or control surgery. Olfactory bulb removal resulted in increased mouse killing, increased irritability to handling, and increased open-field activity. In acquisition trials on a modified passive-avoidance apparatus, control animals habituated rapidly to the apparatus, while OB rats showed little evidence for habituation. All controls showed 24-hour retention of shock on the last acquisition trial, while OB rats showed the typical retention deficit, despite being given a behavioral alternative to withholding a response. The P-A deficit in OB rats appears to be a learning/memory deficit, not the result of heightened activity.

Aluminum ingestion and behavior in the Long-Evans rat.

A variety of behaviors was measured in adult Long-Evans male rats fed ground rat chow containing either no added aluminum, low aluminum (1500 mg/kg), moderate aluminum (2500 mg/kg), or high aluminum (3500 mg/kg). There were no effects of aluminum on either body weight or mouse killing. There was an inverse relationship between brain aluminum and open-field activity. Elevated brain aluminum was correlated with relatively poor performance on a single-trial passive-avoidance task and on a visual discrimination with reversal task.

Postweaning copper restriction and behavior in the Long-Evans rat.

A variety of behaviors was assessed in Long-Evans male rats placed on either a low copper diet, a marginal copper diet, or an adequate copper diet at weaning. Rats in the low copper group had slightly, but significantly, enlarged hearts and gained less weight than rats fed diets containing higher copper levels. Treatment effects were not detected in measurements of muricide, open-field activity, water intake, shock sensitivity, and shock avoidance and memory.

Effects of methomyl and ethanol on behavior in the Sprague-Dawley rat.

Emotional behavior and activity levels were studied following administration of ethanol and/or a carbamate pesticide, methomyl, to rats via a ground chow diet. Acetylcholinesterase levels were lowered following the experimental diets. The group having the greatest reduction in AChE, the methomyl group, showed less evidence for habituation in an open-field test. No differences relative to control subjects were noted on handling and muricide tests.

The effects of colony differences on muricidal behavior in rats within one strain.

Two experiments were performed to investigate the origin of colony differences in muricidal behavior within the same strain of rat. In the first experiment (N = 52 male Long-Evans rats), the first generation offspring of parents from two different colonies were reared under identical conditions and tested for muricide. No differences were found, indicating that an environmental effect accounted for previously observed differences. The second experiment (N = 36 male Long-Evans rats) examined the effects of the presence or absence of mice in the rearing quarters. Again, no differences in muricidal rates were found. Overall, the offspring of killer mothers killed significantly more often than the offspring of nonkiller mothers.

A comparison of male and female alcoholics with an MMPI classification system.

The present study was designed to determine if an MMPI classification system developed for male alcoholics could be successfully extended to female alcoholics. Males and females were compared on the following measures: classifiability, Hs, D, and Mf scales, age and marital status. The results showed that although the examined classification system could be utilized with only limited success, the proportions classified for males and females were similar. A revised classification system resulted in greater classifiability of both males and females. Hs and D scales did not differ between the sexes, but Mf scales did. No differences were found in marital status between males and females. In general, the psychotic and psychopathic alcoholics were younger than the other alcoholic groups, with the neurotics and unclassified alcoholics being the oldest.

The Myers-Briggs type indicator and coronary heart disease.

Researchers have for many years attempted to establish a relationship between coronary heart disease (CHD) and personality type. In our study, 103 subjects completed Form G of the Myers-Briggs Type Indicator (MBTI). Comparisons were made between 93 CHD patients and an age-appropriate control group (Group C) on each of the four MBTI dimensions: Extraversion-Introversion, Sensing-Intuition, Thinking-Feeling, and Judging-Perceiving. The comparison between CHD patients and Group C showed that CHD patients were significantly more likely to prefer sensing and feeling.

Mirex and behavior in the Long-Evans rat.

In two experiments, adult male Long-Evans rats were fed chow containing mirex (1.78 ppm and 17.8 ppm in Experiment 1, 17.8 ppm in Experiment 2) over a several week period and were tested on a variety of behavioral tasks. No differences in behavior were seen between control and experimental animals tested in an open-field apparatus, on VI 30-sec and DRL 20-sec operant paradigms, or on a discrimination-reversal task motivated by escape from footshock.