Sherk H, Ombrellaro M
University of Washington, Department of Biological Structure, Seattle 98195.
Exp Brain Res. 1988;72(2):225-36. doi: 10.1007/BF00250246.
It is widely believed that cells in area 17 send axons specifically to neurons in other cortical areas whose receptive fields coincide with their own. We asked whether this was true in cats for area 17's projection to a large suprasylvian visual area, the Clare-Bishop area. Receptive fields were plotted at multiple sites in the Clare-Bishop area. Then, in area 17, anterograde tracer was injected at a retinotopically-characterized site, giving rise to patches of labeled terminals in the Clare-Bishop area. Receptive field centers recorded within these patches were located close to the visual field location at the injection site in area 17. Receptive fields recorded outside of labeled patches, on the other hand, were never in register with that plotted in area 17. However, due to their large size, even fields located outside of labeled patches often encompassed the visual field point injected in area 17. In other experiments, receptive fields for both neurons and presumed cortical afferents were recorded at the same site in the Clare-Bishop area. The centers of such pairs of receptive fields were on average less than 1 degree apart. Finally, the gaps between widely separated patches of label were investigated. Both physiological and anatomical evidence indicated that a different part of the visual field was represented in gaps than in the adjacent patches.
人们普遍认为，17区的细胞会将轴突专门发送到其他皮层区域中感受野与自身感受野重合的神经元。我们研究了在猫身上，17区向一个大型的上薛氏视觉区域（克莱尔-毕晓普区）的投射是否也是如此。在克莱尔-毕晓普区的多个位点绘制了感受野。然后，在17区，将顺行示踪剂注射到一个经视网膜定位特征化的位点，在克莱尔-毕晓普区产生了标记终末斑块。在这些斑块内记录的感受野中心位于17区注射位点的视野位置附近。另一方面，在标记斑块之外记录的感受野与在17区绘制的感受野从未对齐。然而，由于它们尺寸较大，即使位于标记斑块之外的视野区域通常也包含了在17区注射的视野点。在其他实验中，在克莱尔-毕晓普区的同一位点记录了神经元和假定的皮层传入纤维的感受野。这样一对感受野的中心平均相距不到1度。最后，对广泛分离的标记斑块之间的间隙进行了研究。生理和解剖学证据均表明，间隙所代表的视野部分与相邻斑块不同。
