Increased running wheel activity and dyadic behavior of rats with hippocampal granule cell deficits

Nocturnal hyperactivity induced by prenatal methylazoxymethanol administration as measured in a computerized residential maze

Treatment of female Sprague-Dawley rats with 15 or 25 mg/kg (IP) of methylazoxymethanol acetate (MAM) at gestational day 15 (15 DG) resulted in a dose-dependent reduction of total brain weight of the adult offspring. When tested for spontaneous activity in a residential maze over a 23 hour period, those animals treated with the highest dose of MAM showed an increase in both locomotion and local activity during night hours without changes in the structure of behavior. Animals treated with 15 mg/kg of MAM showed no difference in activity compared to controls despite a significant reduction in brain weight.

The telencephalic limbic system and experimental gastric pathology: a review

The effects of lesions and stimulations of the telencephalic limbic system on experimental gastric ulcers and erosions are reviewed. It is concluded that the centromedial amygdala and the anterior cingulate gyrus are facilitatory structures, whereas the medial prefrontal cortex, posterior cingulate cortex, entorhinal cortex, hippocampus and posterolateral amygdala are inhibitory areas during stressful experiences, e.g., immobilization. Both the centromedial amygdala and the anterior cingulate gyrus may be part of an "ancillary" pain system, mediating the affective components of aversive experiences. The inhibitory structures, on the other hand, are assumed to be part of a "preventive" mechanism which is initiated by the selective nuclear binding of glucocorticoids when under stress.

Cranial irradiation of young rats impairs later learning and growth

Young rats (26 days) were exposed to ionizing radiation of the head of 0, 1200, 2400, or 3000 rads total in 200 rads/day doses. The subsequent growth of irradiated rats was permanently impaired: such impairment was positively related to amount of irradiation. Beginning in adolescence, rats were trained on a horizontal/vertical visual discrimination in a runway task, and although all four groups mastered the discrimination, they differed in their patterns of acquisition. These results indicate long term effects are associated with a cranial irradiation regimen similar to that given to children suffering acute lymphocytic leukemia (ALL).