非稳态噪声对动物行为及心脏自由基损伤的影响

本研究用采集的多用木工机床和冲击电钻发出的噪声对 5天、1 0天和 2 0天三个噪声干扰组的动物进行干扰 ,以研究非稳态噪声对动物行为及心脏组织自由基损伤的影响。结果发现 ,非稳态噪声可引起动物旷场反应中走格数减少 ,站立及洗脸次数增加 ,并可诱发心脏组织的自由基反应 ,导致心脏组织的损害。因此得出结论 :①非稳态噪声可以对动物行为产生影响 ,并随着噪声暴露时间的延长而增强 ;②非稳态噪声可以造成心脏组织的自由基损伤。这一现象提示自由基损伤是介导噪声对心脏功能影响的重要因素之一。     

Fractal dynamics of heart beat interval fluctuations in corticotropin-releasing factor receptor subtype 2 deficient mice

Non-linear fractal analysis of cardiac interbeat time series was performed in corticotropin-releasing factor receptor subtype 2 (CRFR2) deficient mice. Heart rate dynamics in mice constitutes a self-similar, scale-invariant, random fractal process with persistent intrinsic long-range correlations and inverse power-law properties. We hypothesized that the sustained tachycardic response elicited by intraperitoneal (ip) injection of human/rat CRF (h/rCRF) is mediated by CRFR2. In wildtype control animals, heart rate was increased to about maximum levels (~ 750 bpm) while in CRFR2-deficient animals baseline values were retained (~ 580 bpm). The tachycardic response elicited by ip-application is mediated by CRFR2 and is interpreted to result from sympathetic stimulation. However, the functional integrity of CRFR2 would not present a prerequisite to maintaining the responsiveness and resiliency of cardiac control to external environmental perturbations experimentally induced by extrinsic ip-application of h/rCRF or under physiological conditions that may be associated with an increased peripheral release of CRF. Under stressful physiological conditions achieved by novelty exposure, CRFR2 is not involved in the cardiodynamic regulation to external short-term stress. While the hypothesis of involvement of CRFR2 in cardiac regulation upon pharmacological stimulation cannot be rejected, the present findings suggest that the mechanism of action is by sympathetic stimulation, but would not unambiguously allow to draw any conclusions as to the physiological role of CRFR2 in the control of cardiac dynamics.     

Heart rate reactivity in HAD and LAD rats during Pavlovian fear conditioning

Recently, we reported that High-Alcohol-Drinking (HAD) rats exhibited selective deficits in active avoidance learning under alcohol-naive conditions, and that administration of moderate doses of alcohol (0.5 and 1.0 g/kg) facilitated learning in these rats (Blankenship et al., 2000; Rorick et al., 2003b). We hypothesized that the deficits resulted from excessive fear in the aversive learning context and that the anxiolytic properties of alcohol may have contributed to the improved learning that was observed after alcohol administration. This hypothesis was supported by a recent study in which prolonged freezing in HAD rats was seen after a classical fear conditioning procedure (Rorick et al., 2003a). To provide additional evidence that HAD rats indeed exhibit behaviors consistent with the expression of increased fear in aversive learning contexts, we employed a Pavlovian fear conditioning task to measure heart rate in HAD and Low-Alcohol-Drinking (LAD) rats. In this study, HAD (HAD-1 and HAD-2) and LAD (LAD-1 and LAD-2) rats were assigned to one of three pre-exposure conditions: Context Only, Context/Tone, or Sequential (Context Only followed by Context/Tone) Pre-Exposure. Following pre-exposure, fear conditioning acquisition and extinction procedures were identical for all groups. Results indicated that although no baseline differences were observed between HAD and LAD rats, HAD rats receiving Context-Only pre-exposure exhibited excessive heart rate reactivity to the tone conditional stimulus during fear conditioning acquisition, compared to LAD rats receiving the same pre-exposure conditions. These findings support the hypothesis that HAD rats exhibit behaviors consistent with increased fear in aversive learning contexts, as measured by autonomic conditioning.     

Negative emotions and coronary heart disease: Causally related or merely coexistent? A review

Negative emotions have been claimed to be a cause of coronary heart disease (CHD) as well as a consequence of cardiovascular disorders. Early case studies of cardiac disorders of soldiers in battle drew attention to the possibility that strong negative emotional states could cause CHD. Subsequent reports of reactions to natural disasters supported the notion that intense negative emotions could precipitate somatic disorders such as CHD. Since then, numerous studies have investigated relations between negative emotions and CHD. Over the years, retrospective studies have found, for example, that negative emotions are often present before the occurrence of CHD. Cross-sectional studies have indicated that symptoms of depression and anxiety are often present in CHD patients. Prospective studies have shown that the likelihood of CHD tends to be higher for people with negative emotions than for those without them. The main symptoms of negative emotional states that seem to be most closely associated with CHD are nervousness, getting easily upset, feeling fatigue, being indecisive, having sleep disturbances, being usually worried about something, and feeling that others would be better off if oneself were dead. Although the findings appear to support the notion of causal connections between negative emotions and CHD, they fail to provide conclusive proof of such relations. An alternative explanation that could also account for the findings is simply that negative emotions and CHD often coexist.     

Congenital heart disease: A primer for the pediatric neuropsychologist

Congenital heart disease (CHD) affects millions of people worldwide, including over one million children in the United States. Approximately 25% of children born with CHD require intensive surgical intervention within the first year of life. Despite improved rates of survival into adulthood – rates that exceed 90% in the modern era – children and adolescents with CHD remain at risk for neurological injury and a range of neurobehavioral and psychosocial challenges that pose a threat to quality of life across the lifespan. Consequently, as experts in both clinical psychology and brain development, neuropsychologists are becoming increasingly involved in cardiac follow-up and monitoring to promote optimal developmental outcomes. The primary objective of this paper is to provide an evidence-based, clinically-oriented primer on CHD for pediatric neuropsychologists working with this growing population of survivors. Following an introduction to current standard-of-care guidelines for managing children and adolescents with CHD, we present an overview of brain development within the context of CHD, review neuropsychological outcomes, examine factors influencing variability in outcomes, and discuss implications and strategies for clinical assessment.     

Walking versus biofeedback: a comparison of acute interventions for stressed students

Background: High rates of stress-related problems in college students and low utilization of treatment options demonstrate the need for effective stress-reducing interventions that can be self-regulated. This study compared the effect of brief paced-breathing with biofeedback and exercise interventions on heart rate variability, state anxiety and affect. Methods: Students (n?=?32) with high levels of perceived stress completed three 10-min interventions on separate days: paced-breathing with biofeedback (Biofeedback), a self-paced walk (Exercise), and an attention control condition of quiet studying (Quiet Study). Anxiety and affect were measured before (Pre), immediately after (Post0) and 15 mins after (Post15) the intervention. Heart rate variability was measured pre- and post-intervention using electrocardiogram. Results: Biofeedback reduced anxiety more than the exercise condition (Pre to Post0: Biofeedback d?=??0.48, Exercise d?=??0.13). Secondly, Exercise temporarily increased energy (Pre to Post0: d?=?0.67), whereas Biofeedback temporarily increased calmness (Pre to Post0: d?=?0.51). All conditions significantly increased total heart rate variability (p?Conclusions: Biofeedback and Exercise interventions improved emotional states in high-stress college students, but the type of change observed (i.e. energizing, calming or anxiety reducing) depended upon the condition.     

左向右分流型先天性心脏病心力衰竭时神经内分泌失调及对策

左向右分流型先天性心脏病是引起小儿心力衰竭(心衰)主要病因之一。研究已证实神经内分泌紊乱与心衰之间有复杂的相关性。临床应用神经内分泌紊乱拮抗剂,如β-受体阻滞剂、洋地黄制剂、血管紧张素转换酶抑制剂(ACEI)能降低此类患儿心衰的病死率。就此类型先心病出现心衰时神经内分泌紊乱现象及治疗对策的综述。     

不同干预方式、不同应激源对血压、心率的影响

探讨不同干预方式、不同应激源对血压、心率影响的差异。被试为本科生48人,采取干预方式、应激源、实验间期的三因素混合实验设计。干预方式为放松训练和预知,应激源为心算和恐怖影片。实验间期包括基线期、干预期、应激期、恢复期。实验的因变量为每个实验间期的血压和心率。结果显示,心算应激引起的血压和心率升高显著高于恐怖影片应激引起的血压和心率的升高;放松训练组和预知组其干预期的血压和心率值都低于基线期;干预方式和应激源在血压和心率两个指标上交互作用不显著。结果表明,与恐怖情绪引起的紧张相比较,智力操作紧张更容易影响血压和心率;放松训练和预知对于对抗应激时血压和心率升高都起到了一定的作用;不同干预方式对于不同性质的应激源作用没有差别。