Martin K A, Whitteridge D
J Physiol. 1984 Nov;356:291-302. doi: 10.1113/jphysiol.1984.sp015465.
In this study, we examined the hypothesis that some features of the receptive fields of cortical neurones are determined by the extent to which their dendrites can sample from different parts of the visual field representation on the cortex. In particular, the orientation selectivity and size of the receptive fields of cortical neurones were examined for their relationship to the tangential organization of the dendrites of cortical neurones. Single neurones in the visual cortex of anaesthetized and paralysed cats were physiologically characterized and injected intracellularly with horseradish peroxidase (HRP). In some cases it was possible to identify whether the neurones received direct (monosynaptic) or indirect (polysynaptic) input from afferents of the lateral geniculate nucleus. The dendritic arborizations of the HRP-filled cells, sampled from all layers, were reconstructed in three dimensions with computer assistance, and rotated to give the tangential or surface view. The bias in the tangential arrangement of the dendrites was determined by calculating the mean vector angle for the distribution of the dendrites of each cell. This bias was related to the orientation selectivity of the neurones. There was no consistent relationship between orientation selectivity and the tangential bias of the dendritic tree. The width of the receptive fields was compared to the equivalent 'width' of the tangential extent of the dendrites. There was no significant relationship between the two widths. The tangential arrangement of the dendritic field does not appear to be important in determining the orientation selectivity or the size of the receptive fields of neurones in the cat visual cortex. The former feature of the receptive fields may be determined by inhibitory processes, while the extent and number of the afferents providing input to a single neurone may determine the latter property.
在本研究中，我们检验了这样一个假设：皮层神经元感受野的某些特征是由其树突从皮层上视野表征的不同部分进行采样的程度所决定的。具体而言，研究了皮层神经元感受野的方向选择性和大小与皮层神经元树突的切向组织之间的关系。对麻醉和瘫痪猫的视觉皮层中的单个神经元进行生理特性分析，并向其细胞内注射辣根过氧化物酶（HRP）。在某些情况下，可以确定这些神经元是从外侧膝状体核的传入纤维接收直接（单突触）还是间接（多突触）输入。从所有层中采样的HRP填充细胞的树突分支在计算机辅助下进行三维重建，并旋转以给出切向或表面视图。通过计算每个细胞树突分布的平均向量角来确定树突切向排列的偏差。这种偏差与神经元的方向选择性有关。方向选择性与树突树的切向偏差之间没有一致的关系。将感受野的宽度与树突切向范围的等效“宽度”进行比较。这两个宽度之间没有显著关系。在猫视觉皮层中，树突野的切向排列在决定神经元感受野的方向选择性或大小时似乎并不重要。感受野的前一个特征可能由抑制过程决定，而向单个神经元提供输入的传入纤维的范围和数量可能决定后一个特性。
