Mitral cell beta1 and 5-HT2A receptor colocalization and cAMP coregulation: a new model of norepinephrine-induced learning in the olfactory bulb

In the present study we assess a new model for classical conditioning of odor preference learning in rat pups. In preference learning beta(1)-adrenoceptors activated by the locus coeruleus mediate the unconditioned stimulus, whereas olfactory nerve input mediates the conditioned stimulus, odor. Serotonin (5-HT) depletion prevents odor learning, with 5-HT(2A/2C) agonists correcting the deficit. Our new model proposes that the interaction of noradrenergic and serotonergic input with odor occurs in the mitral cells of the olfactory bulb through activation of cyclic adenosine monophosphate (cAMP). Here, using selective antibodies and immunofluorescence examined with confocal microscopy, we demonstrate that beta(1)-adrenoceptors and 5-HT(2A) receptors colocalize primarily on mitral cells. Using a cAMP assay and cAMP immunocytochemistry, we find that beta-adrenoceptor activation by isoproterenol, at learning-effective and higher doses, significantly increases bulbar cAMP, as does stroking. As predicted by our model, the cAMP increases are localized to mitral cells. 5-HT depletion of the olfactory bulb does not affect basal levels of cAMP but prevents isoproterenol-induced cAMP elevation. These results support the model. We suggest the mitral-cell cAMP cascade converges with a Ca(2+) pathway activated by odor to recruit CREB phosphorylation and memory-associated changes in the olfactory bulb. The dose-related increase in cAMP with isoproterenol implies a critical cAMP window because the highest dose of isoproterenol does not produce learning.     

一份特殊的礼物:论宝髻的施舍及其宗教意义

本文以佛典中关于宝髻的故事为例,论述了佛教施舍自己身体的宗教意义。     

从世界到生活形式--维特根斯坦前后期哲学转变原因探析

一般认为,维特根斯坦前后期哲学转变的原因是语言观的变化。本文结合维特根斯坦跨越两种哲学传统的背景,认为哲学转变的根本原因是由于前期本体论的内在缺陷而导致的本体论变化,维特根斯坦前期哲学本体论只局限于可说的“世界”,而不可说的神秘之物则被排除在世界之外,这与维特根斯坦珍视神秘之物的初衷相悖,这种内在矛盾促成了前期本体论向后期本体论的转变,这一转变的重大意义在于后期本体论消泯了可说与不可说的界限,是人类社会实践的坚实基础。     

Personal Relative Deprivation Boosts Materialism

Five studies investigated the relationship between personal relative deprivation and materialism. Study 1 was a cross-sectional survey that revealed a positive association between trait relative deprivation and materialism. In Studies 2a and 2b, we found that relative deprivation, as induced by unjust government policies in an imaginary scenario, increased individuals’ preferences for making more profit than others. Individuals may experience relative deprivation due to unjust treatment or other factors. Study 3 manifested that sense of relative deprivation, resulting from either being treated unjustly or not, gave rise to materialistic desires. In Study 4, we found that relative deprivation influenced materialistic aspirations, above and beyond negative outcomes. Moreover, the impact of relative deprivation could be generalized to aspirations for fame.     

Tensile deformation mechanisms of the hierarchical structure consisting of both twin-free grains and nanotwinned grains

A series of large-scale molecular dynamics simulations have been performed to investigate the tensile properties and atomistic deformation mechanisms for the nanostructured Cu with three typical microstructures: the hierarchical structure consisting of both twin-free grains (d?=?70?nm) and grains with bundles of smaller nanotwins (d?=?70?nm, λ?=?10?nm), the fully nanograined structure and the fully nanotwinned structure. The average flow stress of the hierarchically structure is found to be higher than that calculated by rule of mixture. As compared with that of fully nanograined structure, the strength for the twin-free grains in the hierarchical structure is promoted and gives extra hardening due to the increased dislocation density and dislocation behaviours. It is also found that the nanotwin bundles are more deformable than the twin-free grains in the hierarchical structure according to the deviatoric strain invariant contour. This indicates that the fully nanograined structure cannot only be strengthened to a higher level, but also obtain better ductility by embedded with stronger bundles of smaller nanotwins. Thus, a superior strength–ductility synergy could be obtained in this kind of hierarchical structures, and this novel strategy has also been implemented in bulk austenitic steels or copper by recent experiments.     

Vortex dynamics in La1.86Sr0. 14CuO4 studied by magnetoresistivity

Abstract

Vortex dynamics in La_1.86Sr_0.14CuO₄ have been studied by the measurement of ρ_c ^//i (T, H), where ρ_c ^//i is the c-axis resistivity for H//i (i = c or a-b). We argue that, at temperatures higher than the irreversibility temperature T _irr, the usual vortex picture breaks down owing to the thermal motion of vortices, resulting in a T- and T _in-dependent anisotropic parameter γ. After taking into account the dependence of γ on T and T _irr, we show that at each given temperature we can rescale the ρ_c ^//a-b (T, H) data onto the corresponding ρ_c ^//c (T, H) curves. This scaling property clearly indicates that the Lorentz-force-free mechanism is responsible for ρ_c ^//a-b (T, H). Furthermore, we also show that the measured ρ_c ^//a-b (T, H) data can be explained in terms of the recently developed extended Josephson coupling model which is verified by rescaling ρ_c ^//a-b (T) data for various fields onto a single curve.     

Functional connectivity abnormalities during contextual processing in schizophrenia and in Parkinson’s disease

Functional connectivity was evaluated in patients with schizophrenia (SC) and in patients with Parkinson’s disease (PD) during the performance of a local contextual processing paradigm, to investigate the proposition that functional disconnection is involved with contextual processing deficits in these populations. To this end, we utilized event-related EEG signals, synchronization likelihood and graph theoretical analysis. Local context was defined as the occurrence of a predictive sequence of stimuli before the presentation of a target event. In the SC patients, we observed a decrease in path length (L) in the beta band, for the predictive sequence and for predicted and random targets, compared with controls. These abnormalities were associated with weaker frontal-temporal-parietal connections. In the PD patients we found longer L (theta band) for predicted targets, and higher cluster coefficients for both the predictive sequence (theta band) and predicted targets (alpha and theta bands), compared with controls. Detection of predicted targets was associated with weaker frontal-parietal connections in PD. No group differences were found for randomized standard stimuli in both SC and PD patients. These findings provide evidence of task-specific functional connectivity abnormalities within frontal networks during local contextual processing.     

羞怯与互联网使用的关系

羞怯是在面对新的社会环境和/或意识到社会评价的情境中个体的紧张和不适的一种性格特征。羞怯会阻碍人际交往,互联网的出现可以弥补羞怯的个体在面对面交往时的紧张或不适。互联网的使用对羞怯个体会有双重影响,积极方面的影响可以降低羞怯水平,消极方面的影响会使羞怯个体网络成瘾。未来研究中,需要进一步研究羞怯与互联网使用之间的中介或调节变量,考察羞怯与互联网使用的关系,深入了解二者的关系。