Mitzdorf U, Singer W
J Comp Neurol. 1979 Sep 1;187(1):71-83. doi: 10.1002/cne.901870105.
The spatio-temporal distributions of excitatory synaptic ensemble activities in A17 and A18 of the visual cortex of the macaque monkey have been investigated. The synaptic activities were elicited by electrical stimulation of the primary efferents and were localized by applying the current source density analysis to the intracortically recorded field potentials. The principal results are as follows: 1. In A17, two groups of activity, evoked by fast and slow afferents, respectively, were distinguishable. 2. The fast afferents induced monosynaptic activity in layer IV C alpha and layer VI, disynaptic activity in layer IV C alpha and in the supragranular layers and trisynaptic activity in layer IV B. 3. The slow efferents induced monosynaptic activity in lower layers IV C beta and layer VI, disynaptic activity via strong connections in upper layer IV C beta, further disynaptic activity in layers III and IV B and trisynaptic activity in layers V A and II. 4. With the exception that the CSD data reveal more polysynaptic activity within layer IV, there is good agreement between the spatio-temporal distribution of synaptic activities and the cortical circuit diagrams proposed in anatomical studies. 5. In A18, activities from the slow and fast conducting afferent systems are revealed in layer IV, both most likely mediated by the monosynaptically activated target cells of A17. These activities are passed on to the supra-and infragranular layers. 6. In the lateral geniculate nucleus the safety factor of transmission is higher for activity conveyed by slow-than by fast-conducting retinal afferents. 7. The spatial distribution of monocularly evoked surface potentials failed to reveal the ocular dominance columns. 8. Comparison with the cat indicates that, with respect to the intracortical circuitry and LHN-transmission, there are more similarities between the fast-group activity in the monkey and the y-system in the cat and between the slow-group activity in the monkey and the x-system in the cat than vice versa.
对猕猴视觉皮层A17和A18中兴奋性突触集合活动的时空分布进行了研究。通过对初级传出纤维进行电刺激来引发突触活动，并通过将电流源密度分析应用于皮层内记录的场电位来定位突触活动。主要结果如下：1. 在A17中，分别由快速和慢速传入纤维诱发的两组活动是可区分的。2. 快速传入纤维在IV Cα层和VI层诱发单突触活动，在IV Cα层和颗粒上层诱发双突触活动，在IV B层诱发三突触活动。3. 慢速传出纤维在IV Cβ下层和VI层诱发单突触活动，通过IV Cβ上层的强连接诱发双突触活动，在III层和IV B层诱发进一步的双突触活动，在V A层和II层诱发三突触活动。4. 除了CSD数据显示IV层内有更多的多突触活动外，突触活动的时空分布与解剖学研究中提出的皮层电路图之间有很好的一致性。5. 在A18中，IV层显示出来自慢速和快速传导传入系统的活动，两者最有可能由A17的单突触激活靶细胞介导。这些活动传递到颗粒上层和颗粒下层。6. 在外侧膝状核中，由慢速传导的视网膜传入纤维传递的活动比由快速传导的视网膜传入纤维传递的活动具有更高的传递安全系数。7. 单眼诱发表面电位的空间分布未能揭示眼优势柱。8. 与猫的比较表明，就皮层内电路和LHN传递而言，猕猴中的快速组活动与猫中的y系统之间以及猕猴中的慢速组活动与猫中的x系统之间的相似性比反之亦然更多。
