Steeves J D, Jordan L M
Brain Res. 1984 Jul 30;307(1-2):263-76. doi: 10.1016/0006-8993(84)90480-3.
An autoradiographic tracing technique was used to examine the projections of the classically defined mesencephalic locomotor region (MRL). Injections of [3H]proline and [3H]leucine were made into sites in the caudal mesencephalon which can be stimulated to produce locomotion. The injection sites were confined to the cuneiform nucleus (stereotaxic coordinates P2.0, L4.0, H-1.0). Descending projections were primarily ipsilateral to the gigantocellular and magnocellular reticular formation of the pons and medulla, the dorsal tegmental reticular nucleus, and the nucleus raphe magnus. Some sparse contralateral projections were also observed within the magnocellular and gigantocellular reticular formation. Direct axonal connections with the spinal cord were not consistently observed. Ascending projections were observed to the subthalamic nucleus, caudal hypothalamic nuclei, the centrum medianum nucleus of the thalamus, the ventral tegmental area of Tsai, the superior colliculus, and the periaqueductal gray region. The ascending projections were also ipsilateral, with sparse contralateral labeling confined to areas which received ipsilateral projections. Projections to the contralateral cuneiform nucleus were also consistently observed. The results, when compared to those of another study, suggest that the classical MLR is anatomically distinct from the more medial sites in the mesencephalon which can also induce locomotion.
采用放射自显影示踪技术来研究经典定义的中脑运动区（MRL）的投射。将[3H]脯氨酸和[3H]亮氨酸注射到中脑尾部可被刺激产生运动的部位。注射部位局限于楔形核（立体定位坐标：P2.0，L4.0，H - 1.0）。下行投射主要是同侧至脑桥和延髓的巨细胞和大细胞网状结构、背侧被盖网状核以及中缝大核。在大细胞和巨细胞网状结构内也观察到一些稀疏的对侧投射。未持续观察到与脊髓的直接轴突连接。观察到上行投射至丘脑底核、下丘脑尾侧核、丘脑中央中核、蔡氏腹侧被盖区、上丘以及导水管周围灰质区域。上行投射也是同侧的，稀疏的对侧标记局限于接受同侧投射的区域。也持续观察到了至对侧楔形核的投射。与另一项研究的结果相比，这些结果表明经典的中脑运动区在解剖学上与中脑更内侧也能诱导运动的部位不同。
