Clamped Corticosterone (B) Reveals the Effect of Endogenous B on Both Facilitated Responsivity to Acute Restraint and Metabolic Responses to Chronic Stress

To determine the effects of both corticosterone (B) and chronic stressors on acute ACTH responses to restraint, young male rats were exposed to streptozotocin-induced diabetes, cold (5-7 degreesC) or intracerebroventricular (icv) neuropeptide Y (NPY) for 5 d and then exposed to restraint within 2 h after lights on. Two groups of rats were studied: intact and adrenalectomized replaced with B pellets that maintained plasma B in the normal mean 24-h range of intact rats. In addition to ACTH and B responses to restraint on d 5, body weight, food intake, fat depots, glucose and other hormones were measured to determine the role of stress-induced elevations in B on energy balance. ACTH responses to restraint were normal in intact rats subjected to diabetes or cold. By contrast, there was no ACTH or B response to restraint in NPY-infused intact rats. All 3 groups of chronically stimulated adrenalectomized rats with clamped B had facilitated ACTH responses to restraint compared to their treatment controls. Overall food intake increased in all groups of stressed rats; however, augmented intake occurred only during the light in intact rats and equally in the light and dark in B-clamped rats. White adipose depot weights were decreased by both diabetes and cold and increased by NPY in intact rats; the decreases with cold and increases with NPY were both blunted and changes in fat stores were not significant in adrenalectomized, B-clamped rats. We conclude that: 1. diabetes- and cold-induced facilitation of restraint-induced afferent input to hypothalamic control of the hypothalamo-pituitary-adrenal (HPA) axis is opposed in intact rats by the elevated feedback signal of B secretion; 2. NPY does not induce facilitation of afferent stress pathways; 3. chronic stimulation of the HPA axis induces acute hyperresponsiveness of hypothalamic neurons to restraint provided that the afferent input of this acute stimulus is not prevented by B feedback; 4. stimulus-induced elevations in B secretion result in day-time feeding; 5. insensitivity of both caloric efficiency and white fat stores to chronic stress in adrenalectomized, B-clamped rats results from loss of normally variable B levels.     

Test of the violation of local realism in quantum mechanics with no use of Bell's inequalities

A novel and versatile polarization-entanglement scheme is adopted to investigate the violation of the EPR local realism for a non-maximally entangled two-photon system according to the recent nonlocality proof by Lucien Hardy. In this context the adoption of a sophisticated detection method allows direct determination of any element of physical reality (viz., determined with probability equal to unity in the words of Einstein, Podolsky and Rosen) for the pair system within complete measurements that are largely insensitive to the detector quantum-efficiencies and noise.     

Detection of stimulus change: The hypothetical roles of visual transient responses

Two random-dot patterns (D1 and D2) were displayed briefly in close temporal succession, separated by an interstimulus interval (ISI). The two patterns were identical except that D2 could contain one more element (addition) or one less element (subtraction) than D1. Observers were required to detect the addition or subtraction using a two-alternative forced-choice method. Three experiments were designed to examine Phillips and Singer’s (1974) suggestion that detection of additions and subtractions can be explained in terms of neural ON and OFF responses. Experiment 1 replicated Phillips and Singer’s finding that performance is progressively impaired as the ISI is increased. In Experiment 2, sudden shifts in luminance between D1 and D2 were combined with several durations of ISI to produce transient responses in a novel manner. Experiment 3 explored the roles of transient neural responses and of configurational changes as determinants of performance. Most predictions based on Phillips and Singer’s model were confirmed by the experimental outcomes. Some discrepancies between theory and data are noted, and directions for further research are suggested.     

损毁下丘脑弓状核、中缝背核和蓝斑对大鼠应激镇痛的影响

本文用不能躲避的间歇脚底电刺激引起大鼠应激,用电刺激鼠尾-嘶叫法测定镇痛效应,研究下丘脑弓状核(脑内β-内啡肽能神经元胞体集中的部位)、中缝背核(脑内5-羟色胺能神经元胞体主要集中的部位之一)和蓝斑(脑内去甲肾上腺素能神经元胞体主要集中的部位之一)与应激镇痛的关系。 用新生大鼠腹腔注射谷氨酸-钠的方法损毁弓状核后,用海人酸和电解两种方法损毁中缝背核或蓝斑后,应激镇痛效应均明显减弱。由于谷氨酸-钠和海人酸只选择性地损毁神经元胞体,故认为脑内的β-内啡肽能神经元、5-羟色胺能神经元和去甲肾上腺素能神经元均参与应激的行为镇痛。     

The relation of field dependence to signal detection while imaging

Twelve field-dependent (FD) and 12 field-independent (FI) males were administered 260 trials of a signal detection task in four phases. Signal type (auditory, visual, or no signal) was crossed with four sets of imaging treatments (pure visual representations, pure sounds without visual counterparts, and two sets representing sounds with visual counterparts). Detection of a signal in isolation was 90% accurate, as was the detection of no signal while imaging. Cross-modality imaging interfered with detection of the stimulus but to a significantly lesser extent than did same-modality imaging. In all detection/imaging treatments, FIs were significantly more sensitive to the signal than were FDs; however, FDs and FIs did not differ in accuracy of detecting isolated signals. The results are discussed in terms of the commonalities shared by perception and imaging as they appear in the Perky effect and cognitive style.     

A COMPARISON OF COGNITIVE CONFLICT BETWEEN PERSONS IN WESTERN EUROPE AND THE UNITED STATES1

Etude comparative du conflit cognitif interpersonnel en Europe occidentale et aux Etats-Unis. — La recherche a été menée conjointement dans divers pays européens (Grande-Bretagne, France, Italie, RFA) et aux Etats-Unis, selon la même procédure. On induit des différences cognitives détetminées entre les 2 membres d'un groupe, en les entraînant différemment (ce dont ils ne sont pas conscients) dans une tâche d'apprentissage portant sur des problèmes politiques; il s'ensuit un conflit quand on réunit les deux sujets et qu'on leur demande d'aboutir à des solutions communes. Les résultats montrent que — a) les différences cognitives ne sont pas réduites en Europe alors qu'elles le sont, lentement, aux Etats-Unis; — b) les sujets européens aboutissent moins souvent que les sujets américains à des solutions de compromis; — c) les européens réagissent différemment à l'idée de « Contrôle de l'Etat ». Ce type de recherche peut être utilisé pour étudier le conflit cognitif sur une base interculturelle; les résultats font apparaître des problèmes importants qui n'ont pas encore été étudiés.