Magnesium valproate in learning disabled children with interictal paroxysmal EEG patterns: Preliminary report

While cerebral lateralization has previously been well documented for many neurobehavioral functions, recent research has shown that as people age, formerly lateralized processes recruit more symmetric patterns of neural activity. Such findings provide the foundation for the model of hemispheric asymmetry reduction in older adults, or "HAROLD"[4]. Previous studies that have measured reaction time and movement time have suggested that aging does not affect manual asymmetries. However, whether these findings can be extended to kinematic variables associated with motor coordination remains largely unknown. The purpose of the current study is to determine whether asymmetries in intralimb coordination are also reduced during the aging process. We examined multidirectional reaching in two different right handed age groups, a younger group from 20 to 40 years of age, and an older group, from 60 to 80 years of age. Measures of final position accuracy, precision, and trajectory linearity showed robust asymmetries between the left and right arm groups of young adults. However, the trajectories and accuracies of the older subjects were symmetric, such that our dependent measures were not significantly different between the right and left arm groups. Our findings extend the HAROLD model to motor behavior, suggesting that aging results in decrements in motor lateralization.     

2006 Curt P. Richter award winner: Social influences on stress responses and health

Both positive and negative social interactions can modulate the hypothalamic-pituitary-adrenal (HPA) axis and influence recovery from injuries and illnesses, such as wounds, stroke, and cardiac arrest. Stress exacerbates neuronal death following stroke and cardiac arrest, and delays cutaneous wound healing, via a common mechanism involving stress-induced increases in corticosterone, acting on glucocorticoid receptors. In contrast, hamsters and mice that form social bonds are buffered against stress and heal cutaneous wounds more quickly than socially isolated animals, presumably because the physical contact experienced by the pairs releases oxytocin, which in turn suppresses the HPA axis and facilitates wound healing. Social housing also decreases stroke-induced neuronal death and improves functional recovery, but the mechanism appears to involve suppressing the inflammatory response that accompanies stroke, rather than alterations in HPA axis activity. An interaction between the HPA axis and immune system determines stroke outcome in neonatally manipulated mice that exhibit life-long dampening of the HPA axis. Taken together, these studies provide support for the detrimental effects of stress and identify potential mechanisms underlying the well-documented clinical observation that social support positively influences human health.     

MEMBRANE Na &#180 +;-K &#180 +; ATPase MEDIATED CASCADE IN BIPOLAR MOOD DISORDER,MAJOR DEPRESSIVE DISORDER,AND SCHIZOPHRENIA RELATIONSHIP TO HEMISPHERIC DOMINANCE

The isoprenoid pathway produces digoxin, an endogenous membrane Na &#180 +;-K &#180 +; ATPase inhibitor and regulator of neurotransmitter transport. The objective of the study was to relate digoxin status and hemispheric dominance to the pathogenesis of psychiatric disorders--bipolar mood disorder, major depressive disorder, and schizophrenia. The following parameters were assessed in bipolar mood disorder during the manic phase and depressive phase of the illness as well as in major depressive disorder, and schizophrenia: HMG CoA reductase activity, tryptophan and tyrosine catabolic patterns, red blood cell (RBC) Na &#180 +;-K &#180 +; ATPase activity, and serum magnesium. These parameters were compared to individuals of dif fering hemispheric dominance. The levels of serum digoxin and HMG CoA reductase activity were found to be decreased in the depressive phase of bipolar mood disorder and major depressive disorder with a cor responding increase in RBC Na &#180 +;-K &#180 +; ATPase activity and serum magnesium levels. There was increase in tyrosine and tyrosine catabolites, and a reduction in tryptophan and its catabolites, in the serum in the depressive phase of bipolar mood disorder and major depressive disorder. The neurotransmitter patterns and digoxin levels in the depressive phase of bipolar mood disorder/major depressive disorder correlated with those in right-handed/left hemisphere dominant individual. The neuro transmitter patterns and digoxin levels in the manic phase of bipolar mood disorder and schizophrenia correlated with those in left-handed/right hemisphere dominant individuals. Digoxin status and hemispheric domi nance could correlate with the pathogenesis of psychiatric disorders--schizophrenia, major depressive disorder, and bipolar mood disorder.     

Logistic回归模型中自变量相对重要性的优势分析

目的应用扩展优势分析方法于Logistic回归模型中,为研究者在确定模型中自变量相对重要性提供一种可选择的方法。方法通过计算和比较与某自变量有关的所有可能子模型(即含有该变量的不同组合)的平均贡献增量△R2,以评价该自变量的相对重要性,并应用于实例分析。结果优势分析所得的各变量的总平均贡献之和等于最终模型的决定系数,其重要性排序与标准回归系数的排序不同,且R2M和R2E更适合作为优势分析的指标。结论优势分析可将各自变量对因变量总方差的贡献,分解为已解释方差百分比,且独立于模型,能精确地衡量自变量的相对重要性。     

100例脑卒中患者利手与语言优势半球关系的研究

选择１９８８年５月～１９９６年８月经头颅ＣＴ证实为单侧脑卒中且病灶波及语言相关区的病人１００例，在发病２周内进行失语检查，要求患者接受检查时神志清楚，定向力及记忆力好，无智能障碍，既往无脑病疾病史，其检测结果，左脑病变８０例中，有６６例失语；右脑病变２０例中，仅４例失语。经统计学处理差别有高度显著性，说明中国人左脑和右脑均可能控制语言，语言优势侧多在左侧，同时发现，右利手中，６８例左脑病变者有５８     

d-Amphetamine in squirrel monkeys of different social status: Effects on social and agonistic behavior,locomotion, and stereotypies

The influences of social status on amphetamine-induced behavioral effects in squirrel monkeys were investigated. Social status was determined by constructing a sociogram. d-Amphetamine (0.3–1.0 mg/kg orally, 0.3 and 0.6 mg/kg IM) increased stereotyped head movements and reduced the time spent in the sitting posture in all monkeys (N=25) regardless of sex, age, or social status. The high levels of locomotor activity in dominant and juvenile monkeys were decreased at higher amphetamine doses (0.6 mg/kg IM, 0.6 and 1.0 mg/kg orally), whereas the same doses increased locomotion in otherwise less active subdominant and submissive animals. Low doses of amphetamine (0.1, 0.3 mg/kg) decreased the incidence of agonistic behavior initiated by dominant monkeys, and higher doses (0.6, 1.0 mg/kg) caused these monkeys to change from predominant initiators of agonistic behavior into recipients. At 2 h after amphetamine administration (0.3 mg/kg IM), the high levels of locomotor behavior had returned to baseline, the social isolation began to disappear, and the disrupted agonistic behavior of dominant monkeys returned to control levels, yet the stereotyped head movements continued to occur with high frequency. In half of the monkeys, amphetamine produced a large increase in distress-like vocalizations. Amphetamine-mediated motor stereotypies may be mediated by mechanisms different than those responsible for agonistic behavior. The selective changes in agonistic behavior by dominant monkeys when challenged with amphetamine may reflect a status-related functional alteration of catecholaminergic processes upon which the drug acts.     

Subordination in male talapoin monkeys lowers sexual behaviour in the absence of dominants

Three experiments assessed the consequences of social status for the socio-sexual behaviour and endocrine state of adult male talapoin monkeys (Miopithecus talapoin). In the first study, each of five males was individually placed into a group of adult females. Neither behavioural responses, nor plasma levels of testosterone, cortisol, or prolactin, predicted males' rank or hormone levels when all males were subsequently placed with these females. In the second study, each of four mixed-sex social groups lived continuously in a large cage for periods ranging from 9-15 months. There were marked differences between the behaviour and hormone levels of highest- and lowest-ranking males. In the third study, each highest- and lowest-ranking male from these groups was individually placed with females. Males that had experienced social subordination for long periods (9-15 months) showed infrequent sexual behaviour and had elevated levels of cortisol and prolactin. These results indicate that the experience of chronic social subordination is a strong predictor of how males will subsequently behave, since both the endocrine and behavioural effects of subordination persist even after the dominant males are removed.     

Neural systems and the inhibitory modulation of agonistic behavior: a comparison of mammalian species

The olfactory bulb, lateral septum, medial accumbens, medial hypothalamus, dorsal and median raphe, and amygdala are known from experiments in rats to participate in the inhibitory modulation of defensiveness and predation but not social aggression. The present paper surveys the influence of these structures in the inhibitory control of these same dimensions of agonistic behavior in other species. The existing evidence suggests that lesions in the lateral septum, medial accumbens, medial hypothalamus, or the dorsal and median raphe (or PCPA-induced depletion or serotonin) induce hyperreactivity to the experimenter in mice, rats, cats, dogs, and humans in every instance where they have been tested with one exception. The exception is that lesions in the medial hypothalamus of mice do not induce heightened reactivity. The same lesions do not cause this dramatic increase in reactivity to the experimenter in gerbils, hamsters, guinea pigs, or rabbits but do heighten some other species typical patterns of defensiveness such as alarm calls and avoidance of contact with conspecifics. Lesions in these same areas in monkeys have not been observed to heighten defensive behaviors. Predatory killing or killing of young conspecifics has been observed in hamsters, mice, rats, and cats in every instance where they have been examined following lesions of the olfactory bulbs, lateral septum, medial accumbens, medial hypothalamus, or the dorsal and median raphe nuclei (or PCPA-induced depletion of serotonin). Social aggression has been decreased with these same lesions in each case where they have been examined except for septal lesions in hamsters which have been reported to heighten social aggression. Across species, the consistency with which lesions of the olfactory region, lateral septum, medial accumbens, medial hypothalamus, and dorsal and median raphe nuclei alter defensiveness and predation but not social aggression supports the inference that neural systems exist which subserve the inhibitory modulation of these dimensions of behavior. Finally, the evidence that the disruption of functioning within these structures in humans results in increased agonistic responses to environmental stimuli serves to further establish the important role of this neural circuitry in the normal inhibitory modulation of agonistic behavior in humans.     

Effects of d-amphetamine and diazepam on paired and grouped primate food competition

Two male and two female rhesus monkeys (Macaca mulatta) were the subjects of an experiment designed to assess the effect of d-amphetamine (DA; 0.125, 0.5 and 2.0 mg/kg, IM) and diazepam (DZP; 0.5 and 2.5 mg/kg, IM) on food-getting behavior in paired and group competition. Paired competition results show that in some cases submissive animals, that had previously failed to obtain apple pieces, were successful in obtaining some apple pieces when either the dominant animal of the pair or both subjects were given 0.5 mg/kg DA or 2.5 mg/kg DZP. Results revealed the same effect when all animals (group competition) were given 0.125 and 2.0 mg/kg DA and 2.5 mg/kg DZP. These results appear to indicate that the effect of drugs on food-getting behavior in competitive situations is in some manner influenced by the social status of the animal.