Buchanan S L, Thompson R H, Maxwell B L, Powell D A
Jennings Bryan Dorn VA Medical Center, Columbia, SC 29201.
Exp Brain Res. 1994;100(3):469-83. doi: 10.1007/BF02738406.
The different cytoarchitectonic regions of the medial prefrontal cortex (mPFC) have recently been shown to play divergent roles in associative learning in rabbits. To determine if these subareas of the mPFC, including areas 24 (anterior cingulate cortex), 25 (infralimbic cortex), and 32 (prelimbic cortex) have differential efferent connections with other cortical and subcortical areas in the rabbit, anterograde and retrograde tracing experiments were performed using the Phaseolus vulgaris leukoagglutinin (PHA-L), and horseradish peroxidase (HRP) techniques. All three areas showed local dorsal-ventral projections into each of the other areas, and a contralateral projection to the homologous area on the other side of the brain. All three also revealed a trajectory through the striatum, resulting in heavy innervation of the caudate nucleus, the claustrum, and a lighter projection to the agranular insular cortex. The thalamic projections of areas 24 and 32 were similar, but not identical, with projections to the mediodorsal nucleus (MD) and all of the midline nuclei. However, the primary thalamic projections from area 25 were to the intralaminar and midline nuclei. All three areas also projected to the ventromedial and to a lesser extent to the ventral posterior thalamic nuclei. Projections were also observed in the lateral hypothalamus, in an area just lateral to the descending limb of the fornix. Amygdala projections from areas 32 and 24 were primarily to the lateral, basolateral and basomedial nuclei, but area 25 also projected to the central nucleus. All three areas also showed projections to the midbrain periaqueductal central gray, median raphe nucleus, ventral tegmental area, substantia nigra, locus coeruleus and pontine nuclei. However, only areas 24 and the more dorsal portions of area 32 projected to the superior colliculus. Area 25 and the ventral portions of area 32 also showed a bilateral projection to the parabrachial nuclei and dorsal and ventral medulla. The dorsal portions of area 32, and all of area 24 were, however, devoid of these projections. It is suggested that these differential projections are responsible for the diverse roles that the cytoarchitectonic subfields of the mPFC have been demonstrated to play in associative learning.
内侧前额叶皮质（mPFC）的不同细胞构筑区域最近被证明在兔子的联想学习中发挥着不同的作用。为了确定mPFC的这些子区域，包括24区（前扣带回皮质）、25区（边缘下皮质）和32区（边缘前皮质）与兔子其他皮质和皮质下区域是否有不同的传出连接，使用菜豆白细胞凝集素（PHA-L）和辣根过氧化物酶（HRP）技术进行了顺行和逆行追踪实验。所有这三个区域都显示出向其他每个区域的局部背腹投射，以及向大脑另一侧同源区域的对侧投射。所有这三个区域还显示出一条穿过纹状体的轨迹，导致尾状核、屏状核有大量神经支配，向无颗粒岛叶皮质的投射较轻。24区和32区的丘脑投射相似但不完全相同，投射到内侧背核（MD）和所有中线核。然而，25区的主要丘脑投射是到板内核和中线核。所有这三个区域也投射到腹内侧丘脑核，在较小程度上投射到腹后丘脑核。在外侧下丘脑，在穹窿降支外侧的一个区域也观察到了投射。32区和24区向杏仁核的投射主要到外侧核、基底外侧核和基底内侧核，但25区也投射到中央核。所有这三个区域还显示出向中脑导水管周围中央灰质、中缝正中核、腹侧被盖区、黑质、蓝斑和脑桥核的投射。然而，只有24区和32区更靠背侧的部分投射到上丘。25区和32区腹侧部分也显示出向臂旁核以及背侧和腹侧延髓的双侧投射。然而，32区的背侧部分和整个24区没有这些投射。有人认为，这些不同的投射是mPFC细胞构筑子区域在联想学习中发挥不同作用的原因。
