Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, CNRS UPR3212, 5 rue Blaise Pascal, 67084, Strasbourg, France.
Université de Strasbourg, Strasbourg, France.
Brain Struct Funct. 2018 May;223(4):1747-1778. doi: 10.1007/s00429-017-1585-x. Epub 2017 Dec 6.
The anterior cingulate cortex (ACC), constituted by areas 25, 32, 24a and 24b in rodents, plays a major role in cognition, emotion and pain. In a previous study, we described the afferents of areas 24a and 24b and those of areas 24a' and 24b' of midcingulate cortex (MCC) in mice and highlighted some density differences among cingulate inputs (Fillinger et al., Brain Struct Funct 222:1509-1532, 2017). To complete this connectome, we analyzed here the efferents of ACC and MCC by injecting anterograde tracers in areas 24a/24b of ACC and 24a'/24b' of MCC. Our results reveal a common projections pattern from both ACC and MCC, targeting the cortical mantle (intracingulate, retrosplenial and parietal associative cortex), the non-cortical basal forebrain, (dorsal striatum, septum, claustrum, basolateral amygdala), the hypothalamus (anterior, lateral, posterior), the thalamus (anterior, laterodorsal, ventral, mediodorsal, midline and intralaminar nuclei), the brainstem (periaqueductal gray, superior colliculus, pontomesencephalic reticular formation, pontine nuclei, tegmental nuclei) and the spinal cord. In addition to an overall denser ACC projection pattern compared to MCC, our analysis revealed clear differences in the density and topography of efferents between ACC and MCC, as well as between dorsal (24b/24b') and ventral (24a/24a') areas, suggesting a common functionality of these two cingulate regions supplemented by specific roles of each area. These results provide a detailed analysis of the efferents of the mouse areas 24a/24b and 24a'/24b' and achieve the description of the cingulate connectome, which bring the anatomical basis necessary to address the roles of ACC and MCC in mice.
扣带前皮质（ACC），由啮齿动物的 25、32、24a 和 24b 区组成，在认知、情绪和疼痛中起主要作用。在之前的一项研究中，我们描述了中扣带皮层（MCC）24a 和 24b 区以及 24a'和 24b'区的传入纤维，并强调了扣带传入纤维之间的一些密度差异（Fillinger 等人，Brain Struct Funct 222:1509-1532, 2017）。为了完成这个连接组，我们通过在 ACC 的 24a/24b 区和 MCC 的 24a'/24b'区注射顺行示踪剂，分析了 ACC 和 MCC 的传出纤维。我们的结果揭示了来自 ACC 和 MCC 的共同投射模式，靶区为皮质（扣带内、后扣带回和顶叶联合皮质）、非皮质基底前脑（背侧纹状体、隔核、屏状核、外侧杏仁核基底核）、下丘脑（前、外侧、后）、丘脑（前、背外侧、腹侧、背内侧、中线和板内核）、脑干（导水管周围灰质、上丘、桥脑被盖网状结构、桥脑核、被盖核）和脊髓。与 MCC 相比，ACC 的投射模式总体上更密集，除了这一点之外，我们的分析还揭示了 ACC 和 MCC 之间、背侧（24b/24b'）和腹侧（24a/24a'）区域之间传出纤维的密度和拓扑结构存在明显差异，这表明这两个扣带区域具有共同的功能，每个区域都具有特定的作用。这些结果提供了对小鼠 24a/24b 和 24a'/24b'区传出纤维的详细分析，并实现了扣带连接组的描述，为研究 ACC 和 MCC 在小鼠中的作用提供了必要的解剖学基础。
