Vogt B A, Rosene D L, Peters A
J Comp Neurol. 1981 Sep 10;201(2):265-83. doi: 10.1002/cne.902010210.
The distribution of degenerating thalamic and callosal afferents to cingulate cortex in the rat is analyzed. Both light microscopic silver impregnation and quantitative electron microscopic techniques demonstrate differences in the form, number, and laminar distribution of these two afferents in anterior and posterior cingulate cortices. Afferents from the mediodorsal thalamic nucleus terminate in area 24. Most terminals are in layer IIIb, fewer in layer Ia-b, and least in layers V and VI. In contrast, callosal afferents terminate mainly in layers Ib-c, II, IIIa, V, and VI. Thus, thalamic and callosal afferents terminate in a complementary pattern except in layers Ib and IIIb where they overlap. Quantitative analysis of degenerating axon terminals in area 24 indicates that there may be as many as seven times more callosal than mediodorsal thalamic terminals in this cortex. Projections of the anterior thalamic nuclei terminate in areas 29b and 29c, primarily in layer Ia, with fewer in layers Ib-IV and least in layers V and VI. Callosal afferents end mainly in layers V and VI and less densely in layers I-IV, which results in some overlap of thalamic and callosal afferents in layers Ic, IV, and V. In addition, patterns of termination of callosal afferents in posterior cingulate cortex change at borders between previously defined cytoarchitectural areas. Anterior thalamic terminals in area 29c differ from other thalamocortical afferents described previously in that they form two types of terminals. One is large (2-4 micrometer in diameter) and occurs mainly in layer Ia, whereas the second type is smaller and is present in layers Ib-V. Both types of terminals form asymmetric synapses mainly with dendritic spines.
分析了大鼠中退化的丘脑和胼胝体传入纤维在扣带回皮质的分布。光学显微镜银浸染和定量电子显微镜技术均显示，这两种传入纤维在前扣带回皮质和后扣带回皮质中的形态、数量和层状分布存在差异。来自丘脑背内侧核的传入纤维终止于24区。大多数终末位于IIIb层，Ia - b层较少，V层和VI层最少。相比之下，胼胝体传入纤维主要终止于Ib - c层、II层、IIIa层、V层和VI层。因此，丘脑和胼胝体传入纤维以互补模式终止，除了在Ib层和IIIb层有重叠。对24区退化轴突终末的定量分析表明，该皮质中胼胝体终末数量可能比丘脑背内侧核终末多多达7倍。丘脑前核的投射终止于29b区和29c区，主要在Ia层，Ib - IV层较少，V层和VI层最少。胼胝体传入纤维主要终止于V层和VI层，I - IV层密度较低，这导致丘脑和胼胝体传入纤维在Ic层、IV层和V层有一些重叠。此外，胼胝体传入纤维在后扣带回皮质的终止模式在先前定义的细胞构筑区域边界处发生变化。29c区的丘脑前终末与先前描述的其他丘脑皮质传入纤维不同，它们形成两种类型的终末。一种较大（直径2 - 4微米），主要出现在Ia层，而第二种较小，存在于Ib - V层。两种类型的终末主要与树突棘形成不对称突触。
