Failure to alter sympathoadrenal response to psychosocial stress following aerobic training.

This experiment assessed the impact of aerobic training on sympathoadrenal, heart rate and subjective responses to psychosocial stress. Subjects were six previously sedentary males who demonstrated marked improvement in fitness level following 10 weeks of training. Plasma samples, heart rate and subjective arousal ratings were obtained prior to, during, and following exposure to stressful mental tasks within a laboratory session. With the exception of training-related bradycardia which was manifest throughout the session, no changes in plasma epinephrine and norepinephrine concentrations, heart rate or subjective reactivity or recovery were seen. These findings are inconsistent with the hypothesized beneficial effects of aerobic training on stress-response. Methodological factors such as self-selection inherent in previous correlation work or the duration of the training program should be considered in this context. The potential contribution of training-related bradycardia to enhanced coping with challenging situations is explored.

Post-stroke depression: relationships to functional impairment, coping strategies, and rehabilitation outcome.

This study examined the phenomenon of post-stroke depression and evaluated its impact on rehabilitation outcome. Sixty-four patients presenting to a rehabilitation program within weeks of first stroke were evaluated for depression through self-report measures and staff ratings. Patients also rated the particular coping strategies which they used in dealing with their illness and hospital stay. Physical and occupational therapists provided measures of functional impairment at admission and discharge. A high (47%) prevalence of depression was found in this population, with no overall differences observed between patients with right or left hemisphere lesions. Depressed patients, in comparison to non-depressed, evidenced greater functional impairment at both admission and discharge. However, both groups showed similar gains over the course of rehabilitation. Coping strategies employed by depressed patients appeared to reflect a lower level of participation in the rehabilitation process. A subgroup of patients evaluated 6 weeks after discharge revealed that depression was associated with a worsening on one measure of functional status. These findings indicate that depression is a frequent companion of stroke, that it is associated with degree of functional impairment, and that it may exert a negative impact on the rehabilitation process and outcome.

Poststroke depression and lesion location. An attempted replication.

Recent evidence suggests that poststroke depression is associated with the location of the brain infarct, proximity to the frontal pole being associated with greater depression following left hemisphere injury, and an opposite relationship being seen with injury to the right hemisphere. This study was designed to replicate and extend previous investigation of this issue. Depression was assessed following recent stroke in patients with localized right (n = 16) or left (n = 19) hemisphere lesions. No overall differences between these groups were found on several measures of depression. Although there appeared to be a negative linear relationship between severity of depression and distance of the lesion from the frontal pole in left hemisphere patients, this association failed to attain statistical significance. A curvilinear relationship was evident in right hemisphere patients, with anterior and posterior lesions associated with high depression scores. These data support the notion that lesion location is associated with the severity of poststroke depression, although the nature of this association may be more complex than has previously been suggested.

Experimental manipulation of aerobic fitness and the response to psychosocial stress: heart rate and self-report measures.

To determine whether aerobic fitness training alters response to psychosocial stress, 38 males were randomly assigned to either aerobic, anaerobic (weight-lifting), or waiting-list control groups. Experimental groups met three to four times per week in 1-hr sessions aimed at improving either cardiovascular endurance or muscular strength. Aerobic fitness level, heart rate and subjective response to laboratory psychosocial stress, and self-reports of daily stress, coping resources and psychologic symptoms were assessed prior to and following 10 weeks of training. Although posttraining fitness measures confirmed the effectiveness of aerobic training, no group differences were seen on laboratory or self-report measures. However, for aerobic trainers alone, fitness improvement tended to correlate with faster heart rate recovery following psychosocial stress. Fitness improvement was not correlated with any other psychologic changes. This experiment provides only modest support for the hypothesis that aerobic training alters response to psychosocial stress. It is suggested that future work on the psychologic effects of aerobic fitness explore the contribution of training parameters as well as subject characteristics.

Aerobic fitness level and reactivity to psychosocial stress: physiological, biochemical, and subjective measures.

Aerobic fitness is associated with numerous physiological adaptations which permit physical stress to be coped with more efficiently. The present experiment examined whether aerobic fitness influences emotional response. Heart rate, biochemical measures (catecholamines, cortisol, prolactin, lactic acid), and self-reported arousal and anxiety were monitored in 15 highly trained and 15 untrained subjects at various points before, during and following exposure to a series of psychosocial stressors. Heart rate and subjective arousal level increased markedly during the stressors in both groups. Trained subjects showed higher levels of norepinephrine and prolactin early in the stress period, more rapid heart rate recovery following the stressors, and lower levels of anxiety at the conclusion of the session. This more rapid heart rate and subjective recovery from psychosocial stress, suggests that aerobically trained individuals may be capable of faster recovery in both physiological and subjective dimensions of emotionality. The differences in reactivity profiles between the aerobically trained and untrained were discussed in light of models that have dealt with the adaptiveness of emotional response.

Suppression of voluntary ingestion of morphine by inhibition of dopamine-beta-hydroxylase.

Male Wistar rats were exposed to a free choice between water and a morphine-sucrose solution. Following stabilization of baseline levels of consumption of morphine, the animals were injected for 5 consecutive days with either FLA-57 (45 or 60 mg/kg i.p.), a non-toxic dopamine-beta-hydroxylase inhibitor or its vehicle. The FLA-57 treated animals significantly attenuated their preference for morphine during the injection and post-injection periods although there were no significant differences related to the dosages used. These treatments produced a concomitant reduction in central norepinephrine levels suggesting that norepinephrine may be involved in the mediation of the reinforcing properties of morphine consumed by laboratory rats. The possibility of common neural mechanisms regulating the pharmacological actions of both morphine and ethanol are discussed.