Origins of callosal projections to the supplementary motor area (SMA): A direct comparison between pre-SMA and SMA-proper in macaque monkeys
Origins of callosal projections to the supplementary motor area (SMA): A direct comparison between pre-SMA and SMA-proper in macaque monkeys
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DOI：
10.1002/cne.10087
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发表时间：
2002-01-28
影响因子：
2.5
通讯作者：
Rouiller, EM
中科院分区：
文献类型：
--
作者：
Liu, J;Morel, A;Rouiller, EM
辅助运动区 (SMA) 的两个细分，即前 SMA（头侧）和 SMA 固有区（尾侧），在与脊髓、丘脑和其他同侧运动皮层区域的连接方面表现出不同的功能特性和明显的差异。本研究的目的是在猴子中确定这些细分在胼胝体连接方面是否也存在差异。将两种荧光逆行示踪剂（固蓝和二脒黄）注射到每只动物中，一种注射在前 SMA 中，另一种注射在 SMA 本身中。在前 SMA 或 SMA 本身中注射示踪剂，会在相对的 SMA、前运动皮层 (PM)、扣带运动区 (CMA) 和扣带回中产生大量标记的神经元。 M1 中标记的神经元很少见，只有在注射到 SMA 本体后才能观察到。 SMA 的两个分支在提供胼胝体输入的区域中发现的标记神经元的比例有所不同。 SMA 本体大约有一半的胼胝体输入来自另一半球的对应部分（猴子为 42-65%）。在注射相反的前 SMA 后，在前 SMA 中发现了相当比例的神经元 (32-47%)。前 SMA 从背侧 PM、腹侧 PM 和 CMA 的头侧半部接收到的胼胝体输入多于从其尾侧半部接收的胼胝体输入。此外，前 SMA（而非 SMA 本身）接收来自前额皮质的胼胝体输入。 SMA 本体从背侧 PM 和腹侧 PM 的尾半部接收到的胼胝体输入多于从其嘴侧半部接收的胼胝体输入。 SMA 的两个分支接收来自相同皮质区域（前额皮质和 M1 除外）的胼胝体输入，但它们在每个起源区域的数量贡献方面有所不同。总之，定量数据现在支持这样的观点，即前 SMA 比 SMA-proper.J.Comp.Neurol.443:71-85,2002 接收更多的经胼胝体输入。 (C) 2002 Wiley-Liss, Inc.
The two subdivisions of the supplementary motor area (SMA), the pre-SMA (rostrally) and SMA-proper (caudally), exhibit distinct functional properties and clear differences with respect to their connectivity with the spinal cord, the thalamus, and other homolateral motor cortical areas. The goal of the present study was to establish in monkeys whether these subdivisions also differ with regard to their callosal connectivity. Two fluorescent retrograde tracers (Fast Blue and Diamidino Yellow) were injected in each animal, one in the pre-SMA and the second in the SMA-proper. Tracer injections in the pre-SMA or in SMA-proper resulted in significant numbers of labeled neurons in the opposite SMA, premotor cortex (PM), cingulate motor areas (CMA), and cingulate gyrus. Labeled neurons in M1 were rare, being observed only after injection in the SMA-proper. The two subdivisions of the SMA differed in the proportion of labeled neurons found across areas providing their callosal inputs. The SMA-proper receives about half of its callosal inputs from its counterpart in the other hemisphere (42-65% across monkeys). A comparable proportion of neurons was found in the pre-SMA after injection in the opposite pre-SMA (32-47%). The pre-SMA receives more callosal inputs from the rostral halves of the dorsal PM, the ventral PM, and the CMA than from their caudal halves. In addition, the pre-SMA, but not the SMA-proper, receives callosal inputs from the prefrontal cortex. The SMA-proper receives more callosal inputs from the caudal halves of the, dorsal PM and ventral PM than from their rostral halves. The two subdivisions of the SMA receive callosal inputs from the same cortical areas except the prefrontal cortex and M1), but they differ with respect to the quantitative contribution of each area of origin. In conclusion, quantitative data now support the notion that pre-SMA receives more transcallosal inputs than the SMA-proper.J.Comp.Neurol.443:71-85,2002. (C) 2002 Wiley-Liss, Inc.