目的:探讨低氧和运动训练对大鼠学习记忆的作用和交互作用及其与海马突触传递功能之间的关系。方法:采用交互设计的研究方案对SD大鼠进行8周14.2%的低氧暴露或/和60 min的无负重游泳训练后,通过Morris水迷宫检测大鼠的学习和记忆能力,...目的:探讨低氧和运动训练对大鼠学习记忆的作用和交互作用及其与海马突触传递功能之间的关系。方法:采用交互设计的研究方案对SD大鼠进行8周14.2%的低氧暴露或/和60 min的无负重游泳训练后,通过Morris水迷宫检测大鼠的学习和记忆能力,并测定海马组织中γ-氨基丁酸(GABA)含量和N-甲基-D-天门冬氨酸受体(NMDAR)亚基NR1、NR2B的m RNA表达量。结果:1长期的低氧暴露可使大鼠的潜伏期显著增加(P<0.05),穿越平台的次数显著减少(P<0.05),运动训练能使大鼠的潜伏期显著缩短(P<0.05),穿越平台的次数显著增加(P<0.05),低氧联合运动训练对缩短大鼠潜伏期、提高大鼠穿越平台次数没有显著的交互作用(P>0.05)。2慢性低氧暴露能显著降低海马组织中NR1和NR2B m RNA的表达(P<0.05),运动训练能显著提高海马组织中NR1和NR2B的m RNA表达和降低GABA含量(P<0.05),低氧联合运动训练对海马组织中NR1、NR2B m RNA表达的提高和GABA含量的降低没有显著的交互作用(P>0.05)。结论:1长期的低氧暴露可抑制学习记忆能力,而运动训练能够增加学习记忆能力,虽然运动训练在一定程度上可以改善低氧暴露大鼠的学习记忆能力,但是并不能完全逆转低氧暴露所造成的学习能力下降。2长期的低氧暴露或运动训练可下调或上调海马NR1和NR2B m RNA表达,抑制或增强海马突触功能可塑性,这可能是影响学习记忆能力的重要机制。展开更多
目的:阐明运动训练是否能够影响大脑功能可塑性变化,以及不同任务态下运动员如何诱发大脑皮层功能重组。方法:选取18项研究中的任务态下362名被试的功能磁共振成像(functional magnetic resonance imaging,fMRI)数据,采用激活似然估计法...目的:阐明运动训练是否能够影响大脑功能可塑性变化,以及不同任务态下运动员如何诱发大脑皮层功能重组。方法:选取18项研究中的任务态下362名被试的功能磁共振成像(functional magnetic resonance imaging,fMRI)数据,采用激活似然估计法(activation likelihood estimation,ALE)计算体素被激活的分布情况。结果:运动员组在任务状态下的脑活动产生4个达到显著水平的激活簇;对照组在任务状态下的脑活动产生5个达到显著水平的激活簇;运动员组与对照组相比,运动员组显著激活左侧上顶叶和下顶叶、右侧额下回和额中回,对照组显著激活辅助运动区;在预判任务中,运动员有更广泛的脑区激活,而在执行任务中,对照组有更广泛的脑区激活。结论:长期的运动训练使得运动员的大脑出现功能可塑性变化,表现为减少了在动作执行时与动作控制有关的脑区活动,增加了在预判时与认知理解有关的脑区活动。展开更多
Memristors are designed to mimic the brain’s integrated functions of storage and computing,thus breaking through the von Neumann framework.However,the formation and breaking of the conductive filament inside a conven...Memristors are designed to mimic the brain’s integrated functions of storage and computing,thus breaking through the von Neumann framework.However,the formation and breaking of the conductive filament inside a conventional memristor is unstable,which makes it difficult to realistically mimic the function of a biological synapse.This problem has become a main factor that hinders memristor applications.The ferroelectric memristor overcomes the shortcomings of the traditional memristor because its resistance variation depends on the polarization direction of the ferroelectric thin film.In this work,an Au/Hf0.5Zr0.5O2/p+-Si ferroelectric memristor is proposed,which is capable of achieving resistive switching characteristics.In particular,the proposed device realizes the stable characteristics of multilevel storage,which possesses the potential to be applied to multi-level storage.Through polarization,the resistance of the proposed memristor can be gradually modulated by flipping the ferroelectric domains.Additionally,a plurality of resistance states can be obtained in bidirectional continuous reversibility,which is similar to the changes in synaptic weights.Furthermore,the proposed memristor is able to successfully mimic biological synaptic functions such as long-term depression,long-term potentiation,paired-pulse facilitation,and spike-timing-dependent plasticity.Consequently,it constitutes a promising candidate for a breakthrough in the von Neumann framework.展开更多
Most studies of predator-induced plasticity have focused on documenting how prey species re- spond to predators by modifying phenotypic traits and how traits correlate with fitness. We have previously shown that Pleur...Most studies of predator-induced plasticity have focused on documenting how prey species re- spond to predators by modifying phenotypic traits and how traits correlate with fitness. We have previously shown that Pleurodema thaul tadpoles exposed to the dragonfly Rhionaeschna varie- gata responded strongly by showing morphological changes, less activity, and better survival than non-exposed tadpoles. Here, we tested whether there is a functional link between morphological plasticity and increased survival in the presence of predators. Tadpoles that experienced predation risk were smaller, less developed, and much less active than tadpoles without this experience. Burst speed did not correlate significantly with morphological changes and predator-induced deeper tails did not act as a lure to divert predator strikes away from the head. Although we have previously found that tadpoles with predator-induced morphology survive better under a direct predator threat, our results on the functional link between morphology and fitness are not conclu- sive. Our results suggest that in P. thaultadpoles （1） burst speed is not important to evade preda- tors, （2） those exposed to predators reduce their activity, and （3） morphological changes do not divert predator attacks away from areas that compromise tadpole survivalEE. Our results show that morphological changes in P. thaul tadpoles do not explain burst speed or lure attraction, al- though there was a clear reduction of activity, which itself reduces predation. We propose that changes in tadpole activity could be further analyzed from another perspective, with morphological change as an indirect product of behavior mediated by physiological mechanisms.展开更多
文摘目的:探讨低氧和运动训练对大鼠学习记忆的作用和交互作用及其与海马突触传递功能之间的关系。方法:采用交互设计的研究方案对SD大鼠进行8周14.2%的低氧暴露或/和60 min的无负重游泳训练后,通过Morris水迷宫检测大鼠的学习和记忆能力,并测定海马组织中γ-氨基丁酸(GABA)含量和N-甲基-D-天门冬氨酸受体(NMDAR)亚基NR1、NR2B的m RNA表达量。结果:1长期的低氧暴露可使大鼠的潜伏期显著增加(P<0.05),穿越平台的次数显著减少(P<0.05),运动训练能使大鼠的潜伏期显著缩短(P<0.05),穿越平台的次数显著增加(P<0.05),低氧联合运动训练对缩短大鼠潜伏期、提高大鼠穿越平台次数没有显著的交互作用(P>0.05)。2慢性低氧暴露能显著降低海马组织中NR1和NR2B m RNA的表达(P<0.05),运动训练能显著提高海马组织中NR1和NR2B的m RNA表达和降低GABA含量(P<0.05),低氧联合运动训练对海马组织中NR1、NR2B m RNA表达的提高和GABA含量的降低没有显著的交互作用(P>0.05)。结论:1长期的低氧暴露可抑制学习记忆能力,而运动训练能够增加学习记忆能力,虽然运动训练在一定程度上可以改善低氧暴露大鼠的学习记忆能力,但是并不能完全逆转低氧暴露所造成的学习能力下降。2长期的低氧暴露或运动训练可下调或上调海马NR1和NR2B m RNA表达,抑制或增强海马突触功能可塑性,这可能是影响学习记忆能力的重要机制。
基金the National Natural Science Foundation of China(61674050 and 61874158)the Outstanding Youth Project of Hebei Province(F2016201220)+6 种基金the Outstanding Youth Cultivation Project of Hebei University(2015JQY01)the Training and Introduction of High-level Innovative Talents of Hebei University(801260201300)the Project of Science and Technology Activities for Overseas Researcher(CL 201602)the Project of Distinguished Young of Hebei Province(A2018201231)the Support Program for the Top Young Talents of Hebei Province(70280011807)the Hundred Persons Plan of Hebei Province(E2018050004 and E2018050003)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province(SLRC2019018)。
文摘Memristors are designed to mimic the brain’s integrated functions of storage and computing,thus breaking through the von Neumann framework.However,the formation and breaking of the conductive filament inside a conventional memristor is unstable,which makes it difficult to realistically mimic the function of a biological synapse.This problem has become a main factor that hinders memristor applications.The ferroelectric memristor overcomes the shortcomings of the traditional memristor because its resistance variation depends on the polarization direction of the ferroelectric thin film.In this work,an Au/Hf0.5Zr0.5O2/p+-Si ferroelectric memristor is proposed,which is capable of achieving resistive switching characteristics.In particular,the proposed device realizes the stable characteristics of multilevel storage,which possesses the potential to be applied to multi-level storage.Through polarization,the resistance of the proposed memristor can be gradually modulated by flipping the ferroelectric domains.Additionally,a plurality of resistance states can be obtained in bidirectional continuous reversibility,which is similar to the changes in synaptic weights.Furthermore,the proposed memristor is able to successfully mimic biological synaptic functions such as long-term depression,long-term potentiation,paired-pulse facilitation,and spike-timing-dependent plasticity.Consequently,it constitutes a promising candidate for a breakthrough in the von Neumann framework.
文摘Most studies of predator-induced plasticity have focused on documenting how prey species re- spond to predators by modifying phenotypic traits and how traits correlate with fitness. We have previously shown that Pleurodema thaul tadpoles exposed to the dragonfly Rhionaeschna varie- gata responded strongly by showing morphological changes, less activity, and better survival than non-exposed tadpoles. Here, we tested whether there is a functional link between morphological plasticity and increased survival in the presence of predators. Tadpoles that experienced predation risk were smaller, less developed, and much less active than tadpoles without this experience. Burst speed did not correlate significantly with morphological changes and predator-induced deeper tails did not act as a lure to divert predator strikes away from the head. Although we have previously found that tadpoles with predator-induced morphology survive better under a direct predator threat, our results on the functional link between morphology and fitness are not conclu- sive. Our results suggest that in P. thaultadpoles （1） burst speed is not important to evade preda- tors, （2） those exposed to predators reduce their activity, and （3） morphological changes do not divert predator attacks away from areas that compromise tadpole survivalEE. Our results show that morphological changes in P. thaul tadpoles do not explain burst speed or lure attraction, al- though there was a clear reduction of activity, which itself reduces predation. We propose that changes in tadpole activity could be further analyzed from another perspective, with morphological change as an indirect product of behavior mediated by physiological mechanisms.
