Levesque M, Charara A, Gagnon S, Parent A, Deschenes M
Centre de Recherche en Neurobiologie, Hopital de l'Enfant-Jesus, Universite Laval, Quebec, Canada.
Brain Res. 1996 Feb 19;709(2):311-5. doi: 10.1016/0006-8993(95)01333-4.
Corticostriatal projections arising from the infragranular layers of the motor and second somatosensory cortices were studied in rats after labeling small pools of neurons with biocytin. Camera lucida reconstruction of 263 fibers arising from laminae V and VI revealed that all corticostriatal projections derive from collaterals of lamina V cells whose main axons descend into the cerebral peduncle. In contrast, lamina VI cells do not branch upon the striatum, but upon the thalamus. Together with the results obtained in previous tracing studies, the present data raise the possibility that no neuron is exclusively corticostriatal. We therefore propose that all corticostriatal projections are collaterals given off by the axons of two types of neurons: layer V cells whose main axon project to the brainstem and/or spinal cord, and layer III cells that project to the contralateral hemisphere.
在用生物胞素标记小群神经元后，对大鼠运动皮层和第二躯体感觉皮层颗粒下层产生的皮质纹状体投射进行了研究。对来自V层和VI层的263条纤维进行的明视野重建显示，所有皮质纹状体投射均来自V层细胞的侧支，其主要轴突向下进入大脑脚。相比之下，VI层细胞不在纹状体上分支，而是在丘脑上分支。结合先前追踪研究获得的结果，目前的数据增加了不存在专门的皮质纹状体神经元的可能性。因此，我们提出所有皮质纹状体投射都是由两种类型神经元的轴突发出的侧支：主要轴突投射到脑干和/或脊髓的V层细胞，以及投射到对侧半球的III层细胞。
