Eccles J C
Acta Morphol Hung. 1983;31(1-3):261-84.
Lamina I has two principal components: a meshwork of fine unmyelinated fibres, the so-called horizontal fibres (h.f.); the profusely branching apical dendrites of all pyramidal cells. These dendrites are studded with spines on which the h.f.'s make excitatory synapses in a crossing-over manner. The h.f. system is produced by the fibres that ascend through the modules and bifurcate in lamina I, each branch extending for up to 5 mm from its origin. These ascending fibres are axons of Martinotti cells, and of corticocortical fibre inputs to the module, both ipsilateral and callosal. Electrophysiological investigations have shown that the h.f. system has a powerful excitatory action on the pyramidal cells. There will be developed the hypothesis that the h.f.-pyramidal dendrite system of lamina I is a structure specially designed for the storage of memories. Conjunction of cartridge activation of pyramidal cell dendrites with a selection of impulses in h.f.'s could produce a synaptic potentiation encoding the experience that is dependent on that selection of h.f. impulses. On a later occasion these potentiated synapses could be effective in replaying the coded neuronal pattern and so retrieving the memory.
I层有两个主要成分：精细的无髓纤维网络，即所谓的水平纤维（h.f.）；所有锥体细胞大量分支的顶端树突。这些树突上布满了棘突，水平纤维以交叉的方式在这些棘突上形成兴奋性突触。水平纤维系统由穿过各模块并在I层分支的纤维产生，每个分支从其起源处延伸达5毫米。这些上行纤维是马丁诺蒂细胞的轴突，以及模块的同侧和胼胝体皮质-皮质纤维输入。电生理研究表明，水平纤维系统对锥体细胞有强大的兴奋作用。将提出这样的假说，即I层的水平纤维-锥体细胞树突系统是一个专门设计用于记忆存储的结构。锥体细胞树突的柱状激活与水平纤维中特定冲动的结合，可能产生一种编码依赖于该水平纤维冲动选择的经验的突触增强。在以后的某个时候，这些增强的突触可能有效地重放编码的神经元模式，从而检索记忆。
