Thompson S M, Robertson R T
Department of Anatomy and Neurobiology, College of Medicine, University of California, Irvine 92717.
J Comp Neurol. 1987 Nov 8;265(2):175-88. doi: 10.1002/cne.902650203.
Subcortical afferent projections to the medial limbic cortex were examined in the rat by the use of retrograde axonal transport of horseradish peroxidase. Small iontophoretic injections of horseradish peroxidase were placed at various locations within the dorsal and ventral cingulate areas, the dorsal agranular and ventral granular divisions of the retrosplenial cortex and the presubiculum. Somata of afferent neurons in the thalamus and basal forebrain were identified by retrograde labeling. Each of the anterior thalamic nuclei was found to project to several limbic cortical areas, although not with equal density. The anterior dorsal nucleus projects primarily to the presubiculum and ventral retrosplenial cortex; the anterior ventral nucleus projects to the retrosplenial cortex and the presubiculum with apparently similar densities; and the anterior medial nucleus projects primarily to the cingulate areas. The projections from the lateral dorsal nucleus to these limbic cortical areas are organized in a loose topographic fashion. The projection to the presubiculum originates in the most dorsal portion of the lateral dorsal nucleus. The projection to the ventral retrosplenial cortex originates in rostral and medial portions of the nucleus, whereas afferents to the dorsal retrosplenial cortex originate in caudal portions of the lateral dorsal nucleus. The projection to the cingulate originates in the ventral portion of the lateral dorsal nucleus. Other projections from the thalamus originate in the intralaminar and midline nuclei, including the central lateral, central dorsal, central medial, paracentral, reuniens, and paraventricular nuclei, and the ventral medial and ventral anterior nuclei. In addition, projections to the medial limbic cortex from the basal forebrain originate in cells of the nucleus of the diagonal band. Projections to the presubiculum also originate in the medial septum. These results are discussed in regard to convergence of sensory and nonsensory information projecting to the limbic cortex and the types of visual and other sensory information that may be relayed to the limbic cortex by these projections.
利用辣根过氧化物酶的逆行轴突运输法，在大鼠中研究了向内侧边缘皮质的皮质下传入投射。将微量辣根过氧化物酶离子电渗注入置于背侧和腹侧扣带区、压后皮质的背侧无颗粒和腹侧颗粒区以及前下托的不同位置。通过逆行标记确定丘脑和基底前脑传入神经元的胞体。发现丘脑前核的每一个都投射到几个边缘皮质区域，尽管密度并不相同。背侧前核主要投射到前下托和腹侧压后皮质；腹侧前核投射到压后皮质和前下托，密度明显相似；内侧前核主要投射到扣带区。从背外侧核到这些边缘皮质区域的投射以松散的拓扑方式组织。投射到前下托的起源于背外侧核的最背侧部分。投射到腹侧压后皮质的起源于该核的嘴侧和内侧部分，而投射到背侧压后皮质的传入纤维起源于背外侧核的尾侧部分。投射到扣带的起源于背外侧核的腹侧部分。丘脑的其他投射起源于板内核和中线核，包括中央外侧核、中央背核、中央内侧核、旁中央核、连合核和室旁核，以及腹内侧核和腹前核。此外，从基底前脑到内侧边缘皮质的投射起源于斜角带核的细胞。投射到前下托的也起源于内侧隔。就投射到边缘皮质的感觉和非感觉信息的汇聚以及这些投射可能传递到边缘皮质的视觉和其他感觉信息的类型对这些结果进行了讨论。
