Groenewegen H J
Department of Anatomy and Embryology, Vrije Universiteit, Amsterdam, The Netherlands.
Neuroscience. 1988 Feb;24(2):379-431. doi: 10.1016/0306-4522(88)90339-9.
The aim of the present study was to determine the organization of the afferents of the mediodorsal thalamic nucleus in relation to the reciprocal connections of this nucleus with different areas of the prefrontal cortex. For this purpose injections of horseradish peroxidase, or horseradish peroxidase conjugated to wheatgerm agglutinin were placed in different parts of the mediodorsal nucleus. These experiments revealed the organization of the reciprocal mediodorsal-prefrontal connections since wheatgerm agglutinin-horseradish peroxidase is transported effectively in anterograde and retrograde directions. Injections of wheatgerm agglutinin-horseradish peroxidase or fluorescent tracers were placed in different portions of the prefrontal cortex, and the lectin Phaseolus vulgaris leucoagglutinin was injected in the mediodorsal nucleus in order to verify in more detail the point-to-point relationship in the mediodorsal-prefrontal connections. The organization of a number of the subcortical afferents to the mediodorsal nucleus was determined in detail using injections of Phaseolus vulgaris leucoagglutinin, wheatgerm agglutinin-horseradish peroxidase, or tritiated amino acids in areas identified as a source of mediodorsal afferents in the retrograde tracing experiments. These anterograde tracers were injected in different parts of the pallidal complex, the amygdala, the lateral hypothalamus, the lateral entorhinal cortex, the ventral mesencephalon, the superior colliculus and the dorsal tegmental region. The results of the present experiments indicate that the mediodorsal nucleus, on the basis of its cyto-, myelo- and chemoarchitecture as well as the organization of its reciprocal connections with the prefrontal cortex, can be subdivided into a medial, a central, a lateral and a paralamellar segment. Apart from this subdivision along a mediolateral axis, rostrocaudal and dorsoventral differences are also evident in the structural organization and connectivity of the mediodorsal nucleus. A number of subcortical structures send fibres to all parts of the mediodorsal nucleus. The reticular thalamic nucleus projects to the mediodorsal nucleus in a topographical way such that its rostral part is connected with the rostral part of the nucleus, whereas more caudal and ventral areas in the reticular thalamic nucleus are connected with more caudal parts of the mediodorsal nucleus. Regions in the brainstem that project to all parts of the mediodorsal nucleus include the mesencephalic raphé nuclei, the locus coeruleus, the rostral part of the central gray substance and the reticular formation.(ABSTRACT TRUNCATED AT 400 WORDS)
本研究的目的是确定丘脑背内侧核传入纤维的组织方式，以及该核与前额叶皮质不同区域的相互连接关系。为此，将辣根过氧化物酶或与麦胚凝集素结合的辣根过氧化物酶注入丘脑背内侧核的不同部位。由于麦胚凝集素 - 辣根过氧化物酶能有效地进行顺行和逆行运输，这些实验揭示了丘脑背内侧核与前额叶皮质之间相互连接的组织方式。将麦胚凝集素 - 辣根过氧化物酶或荧光示踪剂注入前额叶皮质的不同部位，并将菜豆白细胞凝集素注入丘脑背内侧核，以更详细地验证丘脑背内侧核与前额叶皮质连接中的点对点关系。使用菜豆白细胞凝集素、麦胚凝集素 - 辣根过氧化物酶或氚标记氨基酸注入在逆行追踪实验中被确定为丘脑背内侧核传入纤维来源的区域，详细确定了丘脑背内侧核的一些皮质下传入纤维的组织方式。这些顺行示踪剂被注入苍白球复合体、杏仁核、外侧下丘脑、外侧内嗅皮质、腹侧中脑、上丘和背侧被盖区的不同部位。本实验结果表明，基于丘脑背内侧核的细胞结构、髓鞘结构和化学结构以及其与前额叶皮质相互连接的组织方式，可将其分为内侧、中央、外侧和旁板层段。除了沿内外侧轴的这种细分外，丘脑背内侧核的结构组织和连接性在前后和背腹方向上也存在明显差异。一些皮质下结构向丘脑背内侧核的所有部位发送纤维。丘脑网状核以拓扑方式投射到丘脑背内侧核，使其 Rostral 部分与该核的 Rostral 部分相连，而丘脑网状核中更靠尾侧和腹侧的区域与丘脑背内侧核更靠尾侧的部分相连。投射到丘脑背内侧核所有部位的脑干区域包括中脑缝核、蓝斑、中央灰质的 Rostral 部分和网状结构。（摘要截断于400字）
