The tractable contribution of synapses and their component molecules to individual differences in learning.
The tractable contribution of synapses and their component molecules to individual differences in learning.
复制标题
突触及其组成分子对学习个体差异的易于处理的贡献。
DOI：
10.1016/s0166-4328(99)00184-9
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发表时间：
2000
影响因子：
2.7
通讯作者：
Gandhi,CC
中科院分区：
文献类型：
--
作者：
Matzel,LD;Gandhi,CC
尽管曾经对心理学家和神经生理学家都具有中心重要性，但对学习中个体差异的神经基础的阐明不再吸引广泛的研究努力，而是在当代学科中占据了很大的历史兴趣。人们对这门学科的兴趣下降，部分原因是几十年前形成的一种观念，即学习方面的个体差异不像以前认为的那样容易量化。此外，该领域的主流假设在复杂且难以接近的脊椎动物神经系统所施加的限制下无法验证。使用“模型系统”的方法，可以识别组成神经网络的单个细胞和突触相互作用，我们已经回到了这个问题，并建立了一个框架，通过这个框架，我们可以开始辨别个体之间学习能力差异的基础。在海洋软体动物Hermissenda中，我们发现对递质胞分泌的共同影响在整个神经系统中均匀表达，无论递质系统或受体类别如何。虽然在个体内表达一致，但这种对突触效能的影响在动物之间表达不同。重要的是，单个神经系统中表达的胞吐的基础效率与该神经系统中神经元/突触易化的活动依赖形式的诱导程度密切相关，并预测了完整动物学习巴甫洛夫联想的能力。此外，我们已经确定，老年动物的基础突触效能下降，由慢性突触前Ca2+“泄漏”引起，可能导致与年龄相关的学习障碍。由于胞外级联的某些基本成分在细胞类型、传递系统和物种中广泛保守，因此我们所描述的原理可能对理解学习中的正常变异性具有广泛的意义，而且对于开发补偿轻度学习缺陷和与年龄相关的认知衰退的特定策略也具有广泛的意义。
Though once of central importance to psychologists and neurophysiologists alike, the elucidation of neural substrates for individual differences in learning no longer attracts a broad research effort and occupies a place of largely historical interest to the contemporary disciplines. The decline in interest in this subject ensued in part from the perception, arrived at decades ago, that individual differences in learning were not quantified as easily as had once been presumed. Furthermore, the dominant hypotheses in the field defied testing within the constraints imposed by the complex and largely inaccessible vertebrate nervous system. Using a ‘model systems’ approach where the individual cells and synaptic interactions that comprise a neural network can be identified, we have returned to this question and have established a framework by which we can begin to discern the basis for much of the variability between individuals in their capacity to learn. In the marine mollusc Hermissenda, we have found that a common influence on transmitter exocytosis is expressed homogeneously throughout the nervous system regardless of transmitter system or receptor class. Though uniformly expressed within an individual, this influence on synaptic efficacy is differentially expressed between animals. Importantly, the basal efficiency of exocytosis expressed in an individual nervous system is strongly correlated with the degree to which activity-dependent forms of neuronal/synaptic facilitation can be induced in that nervous system, and predicts the capacity for the intact animal to learn a Pavlovian association. Furthermore, we have established that a decline in basal synaptic efficacy in aged animals, arising from chronic presynaptic Ca2+‘leak’, may contribute to age-related learning impairments. Because certain fundamental components of the exocytotic cascade are conserved widely across cell types, transmitter systems and species, the principles that we describe may have broad implications for understanding normal variability in learning, but also, in the development of specific strategies to compensate for mild learning deficits and age-related cognitive decline.