Kelley A E, Domesick V B
Neuroscience. 1982 Oct;7(10):2321-35. doi: 10.1016/0306-4522(82)90198-1.
We have investigated the distribution and organization of the projection from the hippocampal formation to the nucleus accumbens in the rat. In the first experiments, horseradish peroxidase was injected into the fimbria fornicis. This procedure resulted in massive anterograde labelling of fornix fibers, and enabled the hippocampo--accumbens projection to be charted in detail. Labelled fornix fibers are distributed to the entire length of the nucleus accumbens and do not spread lateral to the anterior limb of the anterior commissure, that is, the projection is limited to the medial nucleus accumbens. Terminal labelling is particularly dense in a caudal dorsomedial sector of accumbens immediately adjacent to the septum. In the second part of the study, horseradish peroxidase was microelectrophoretically injected into the nucleus accumbens, in order to confirm the findings from the anterograde experiments. When the deposit was localized within the fornix distribution field, as indicated by the first experiment, retrogradely-labelled cells were observed in the subiculum, prosubiculum, and to a lesser extent, in hippocampal field CAI. When the deposit was located outside of the fornix distribution field, no hippocampal labelling was noted. The topography of the projection, suggested by the retrograde labelling experiments, is discussed. The findings confirm earlier reports of such a projection from the hippocampal formation to the nucleus accumbens, and with the use of a relatively novel anterograde-horseradish peroxidase technique, provide a picture of fiber labelling representing the entire field of origin of the fornix system. The striatal projection field of this pathway is discussed in relation to other striatal afferents, with particular emphasis on limbic afferentation of the striatum. Finally, the so-called 'hippocampal district' of striatum is discussed with respect to its neurotransmitter composition, as well as its functional importance regarding limbic system influence on central motor mechanisms.
我们研究了大鼠海马结构向伏隔核投射的分布和组织情况。在最初的实验中，将辣根过氧化物酶注入穹窿伞。这一操作导致穹窿纤维大量顺行标记，从而能够详细描绘出海马-伏隔核投射。标记的穹窿纤维分布于伏隔核的全长，且不会延伸到前连合前肢的外侧，也就是说，投射仅限于伏隔核内侧。终末标记在紧邻隔区的伏隔核尾侧背内侧区尤为密集。在研究的第二部分，将辣根过氧化物酶微电泳注入伏隔核，以证实顺行实验的结果。当注入部位位于如第一个实验所示的穹窿分布区域内时，在海马下托、前海马下托以及程度较轻的海马CA1区观察到逆行标记的细胞。当注入部位位于穹窿分布区域之外时，则未观察到海马标记。讨论了逆行标记实验所提示的投射拓扑结构。这些发现证实了早期关于海马结构向伏隔核投射的报道，并通过使用一种相对新颖的顺行-辣根过氧化物酶技术，提供了一幅代表穹窿系统整个起源区域的纤维标记图。讨论了该通路的纹状体投射区域与其他纹状体传入纤维的关系，特别强调了纹状体的边缘传入。最后，讨论了纹状体所谓的“海马区”的神经递质组成，以及其在边缘系统对中枢运动机制影响方面的功能重要性。
