Effects of aerobic exercise training on brain structure and psychological well-being in young adults.

AIM: There is convergent evidence that exercise increases psychological well-being; however, the mechanism of this psychological effect of exercise is not yet completely understood. The purpose of this study was to examine the effects of aerobic exercise training on brain structure and psychological well-being in young adults. METHODS: University students who had not regularly exercised were divided into training group (N.=15) and control group (N.=15). The training group performed a total 30 periods of aerobic exercise training, while the control group never performed. Whole-brain magnetic resonance imaging scans and mental health questionnaire examinations were performed before and after the exercise training period for all of the participants. A voxel-based morphometry (VBM) analysis was used to compare the changes in gray-matter volumes in the two groups. VBM is an objective whole-brain technique for characterization of regional cerebral volume and tissue concentration differences in structural magnetic resonance images. RESULTS: The results of VBM analysis revealed no change in gray-matter volume in the training group, although the gray-matter volume of the left insula was significantly decreased in the control group after the exercise training period. The training group exhibited significant improvement in some scores on the mental health questionnaire after the exercise training period, compared with the control group. CONCLUSIONS: These findings suggest that aerobic exercise training may inhibit gray-matter volume loss in the insula, and that a relationship may exist between preservation of insula gray-matter and improvement of psychological well-being by aerobic exercise training.

Differential changes in rat brain noradrenaline turnover produced by continuous and intermittent restraint stress.

This experiment was performed to investigate differential effects of continuous and intermittent restraint stress on noradrenaline (NA) turnover in brain regions of male Wistar rats by measuring levels of a major metabolite of NA, 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4) levels, as well as by measuring levels of plasma corticosterone and organ weights of the thymus, spleen, and adrenal glands. Rats in the 15-min and 30-min intermittently stressed groups showed significantly larger increases in MHPG-SO4 levels in most brain regions relative to those in the 90-min and 180-min continuously stressed groups, even though the total stress duration was equal or shorter. Body weight loss and loss of relative thymus weight in the 15-min intermittently stressed groups were the most marked among the five treatment groups. These findings suggest that stress-rest cyclicity is critical in determining the extent of stress-induced brain NA turnover and peripheral physiological responses.

Atypical anxiolytic profile of buspirone and a related drug, SM-3997, in a modified forced swim test employing straw suspension.

Previous reports have shown that immobility time increases in the presence of suspended straws in association with an inhibition of straw-climbing behavior after acute administration of a prototypical anxiolytic benzodiazepine (BZD) such as diazepam. In this modified forced swim (MFS) test employing straw suspension, the effects of two new non-BZD compounds were tested and compared with those of diazepam (0.5, 1, and 5 mg/kg, IP) used in a previous MFS test. After a 5-min test of forced swimming, four straws were suspended just above the surface of the water and subsequently the straw-climbing trials were counted for 5 min as an index of escape behaviors induced by negative emotionality (stress and/or anxiety). Rats were injected IP with either saline, buspirone HCl (0.5, 1, and 5 mg/kg), or a related compound, SM-3997 (5, 10, and 20 mg/kg), 30 min before testing. At lower doses, both buspirone (0.5, 1 mg/kg) and SM-3997 (5, 10 mg/kg) reduced the duration of immobility, as opposed to that of diazepam. Conversely, buspirone at the highest dose of 5 mg/kg significantly prolonged the duration of immobility, and SM-3997 at 20 mg/kg also prolonged its duration, indicating a biphasic effects. All doses of buspirone and SM-3997 inhibited straw-climbing counts, in the same manner as diazepam. These results suggest that buspirone may possess relatively weak and/or atypical anxiolytic effects at lower doses, whereas at 5 mg/kg this compound may have an anxiolytic effect. In addition, SM-3997 may be a less potent anxiolytic drug than buspirone in the MFS test following a single-injection protocol.

Effects of stress, non-stress cyclicity on hypothalamic noradrenaline release in rats.

The effects of continuous stress and intermittent stress at short intervals on rat hypothalamic noradrenaline (NA) release were assessed by measuring the levels of a principal metabolite of NA, 3-methoxy-4-hydroxy-phenylethyleneglycol sulfate (MHPG-SO4) in male Wistar rats. The rats were exposed to one of five restraint stress conditions, unstressed (control), six 15 min intermittent stress periods (interspersed with 18 min non-stress periods), three 30 min intermittent stress periods (interspersed with 45 min non-stress periods), 90 min continuous stress period or 180 min continuous stress period. The 15 min intermittently stressed rats had significantly larger increases in hypothalamic MHPG-SO4 than the single 90 min and 180 min continuously stressed rats, while the 30 min intermittently stressed rats were significantly different from only the 180 min continuously stressed rats. In a comparison of the 15 min and 30 min intermittently stressed rats, which had the same total duration of stress exposure; the 15 min group had larger increases in MHPG-SO4 levels than the 30 min group. This study provides supporting evidence for the role of stress cyclicity in determining the extent of stress-induced NA release from the hypothalamus.

Lupus anticoagulant as a risk factor for cerebral infarction and habitual abortions.

A case involving a 34-year-old female with a progressive hemiparesis is described. She had a history of repeated spontaneous abortions. The CT and magnetic resonance imaging (MRI) showed a multiple cerebral infarction. A 99mTc perfusion lung scintigram demonstrated diffuse bilateral perfusion defects in the lungs. The presence of lupus anticoagulant (LA) was detected from the laboratory data and the thrombosis in the genital organ. The repeated abortions were probably due to thrombosis in the placental vessels caused by LA. High dose steroid therapy was effective in suppressing the LA activity and in preventing progression of the clinical symptoms.

Expression of aggression attenuates stress-induced increases in rat brain noradrenaline turnover.

This experiment determined whether or not an aggressive biting response could attenuate stress-induced increases in brain noradrenaline (NA) turnover, by measuring contents of NA and its major metabolite, 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4), in discrete brain regions of male Wistar rats. Rats were exposed to a 10 min supine restraint stress with or without being allowed to bite a wooden stick. In each group, the animals were sacrificed by decapitation either 0 min or 50 min after release from stress. NA and MHPG-SO4 levels were unaffected in both biting and non-biting groups immediately after stress, as compared to controls. Fifty min after release from stress, increases in plasma corticosterone levels induced by stress recovered in the biting group but remained high in the non-biting group. MHPG-SO4 levels significantly increased in the hypothalamus, amygdala, thalamus, midbrain, basal ganglia, hippocampus and cerebral cortex in both stressed groups, however the increases in the non-biting group were significantly higher than those in the biting group in the first 5 of these regions. These findings clearly show that giving rats an opportunity to express aggression during stress exposure results in a significant attenuation of stress-induced increases in NA turnover in specific brain regions, such as the hypothalamus and limbic areas. The present experiment provides a possible neurochemical basis for clinical studies showing that suppression of anger in a stressful, frustrating situation leads to pathological consequences in humans.