Guedes R, Watanabe S, Creutzfeldt O D
Exp Brain Res. 1983;49(1):13-27. doi: 10.1007/BF00235537.
This paper reports on experiments in which the effect of disconnection of association fibres from Area 17/18 to the posterior suprasylvian cortex (PSSC) was investigated. In the control experiments, all neurons had large receptive fields in the central 5-10 degrees of the visual field without detailed retinotopy. In the medial bank of PSSC, receptive fields were located in the contralateral visual field, while receptive fields of neurons in the lateral bank were located ipsilaterally. Neurons in PSSC could be excited by electrical stimulation of the ipsilateral Area 17/18 boundary, of the medial pulvinar (N. lat. post., pars. lat.) and the lateral geniculate body. About 2/3 of all neurons could be excited from all these regions, although with varying latencies. After acute and chronic subpial undercutting of the representation of the central 5-10 degrees of the ipsilateral area 17/18, visual response properties including direction sensitivity, receptive field size and ocularity of PSSC-neurons in the medio-posterior bank did not change significantly. After ablation of the whole contralateral visual cortex (including PSSC and a wide region of the contralateral Clare-Bishop area) the input from the ipsilateral eye was considerably diminished, but other response properties did not change significantly. These essentially negative findings are discussed in relation to different findings of other authors, and it is argued that the subpial undercutting of only the central visual field representation may have prevented damage to the ipsilateral suprasylvian cortex and its afferents, which is difficult to avoid if the whole area 17 is ablated by suction. It is proposed, that association fibres may only "unspecifically" excite neurons in related association areas rather than impose onto them specific response features. These latter are derived, also in association areas, essentially from their thalamic afferents and their intracortical interaction.
本文报道了有关切断从17/18区至后上薛氏回皮质（PSSC）的联合纤维所产生影响的实验研究。在对照实验中，所有神经元在视野中央5 - 10度范围内均具有大的感受野，且无精细的视网膜拓扑结构。在PSSC的内侧壁，感受野位于对侧视野，而外侧壁神经元的感受野则位于同侧。PSSC中的神经元可通过对同侧17/18区边界、内侧丘脑枕（外侧后核，外侧部）以及外侧膝状体的电刺激而兴奋。尽管潜伏期各不相同，但约2/3的神经元可被所有这些区域兴奋。在对同侧17/18区中央5 - 10度的代表区进行急性和慢性软膜下横切后，中后侧壁PSSC神经元的视觉反应特性，包括方向敏感性、感受野大小和眼优势，均未发生显著变化。在切除整个对侧视觉皮质（包括PSSC和对侧克莱尔 - 毕晓普区的广泛区域）后，同侧眼的输入显著减少，但其他反应特性并未发生显著改变。结合其他作者的不同研究结果对这些基本为阴性的发现进行了讨论，并且认为仅对中央视野代表区进行软膜下横切可能避免了对同侧上薛氏回皮质及其传入纤维的损伤，而如果通过抽吸切除整个17区则难以避免这种损伤。有人提出，联合纤维可能只是“非特异性地”兴奋相关联合区域中的神经元，而非赋予它们特定的反应特征。这些后者的特征，同样在联合区域中，主要源自它们的丘脑传入纤维及其皮质内相互作用。
