Trok K, Freund R K, Palmer M R, Olson L
Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Brain Res. 1994 Oct 3;659(1-2):138-46. doi: 10.1016/0006-8993(94)90873-7.
Skeletal muscle from embryonic day 20 (E20) was combined with E15 rat spinal cord in the anterior chamber of the eye of adult albino rats. The two grafts were either transplanted concomitantly or sequentially, in which case muscle tissue was added 4 months after the spinal cord. Control groups received a single graft of either spinal cord or skeletal muscle. Survival and intraocular growth were observed through the cornea. After maturation in oculo, the double grafts were examined immunohistologically utilizing antisera to neurofilament (NF) and acetylcholinesterase (AChE). The grafts were also evaluated using electrical stimulation to determine functional connectivity. The spinal cord and skeletal muscle grafts were found to exert reciprocal trophic effects on each other, evidenced as a larger muscle mass in skeletal muscle grafts allowed to develop in the presence of spinal cord tissue, and a larger volume of spinal cord grafts allowed to develop together with a skeletal muscle graft, respectively. Immunohistochemistry revealed NF-positive nerve fibers leaving the spinal cord graft and entering the muscle tissue. AChE-positive endplates developed in the muscle grafts. Electrical stimulation of the spinal cord part of double-graft combinations generally elicited contractile responses in specific areas of the muscle cograft. These results demonstrate both structural and functional connections between grafts of spinal cord and skeletal muscle tissue in vivo. The fact that such connections were also established between a mature (adult) spinal cord graft and fetal skeletal muscle tissue suggests that some alpha-motoneurons are able to survive for many months in the intraocular grafts without an appropriate target, and that they are able to subsequently innervate skeletal muscle targets.
将胚胎第20天（E20）的骨骼肌与E15大鼠脊髓组合，植入成年白化大鼠眼前房。两种移植物要么同时移植，要么先后移植，在后一种情况下，肌肉组织在脊髓移植4个月后添加。对照组接受单一的脊髓或骨骼肌移植物。通过角膜观察移植物的存活和眼内生长情况。眼内成熟后，利用抗神经丝（NF）和乙酰胆碱酯酶（AChE）抗血清对双重移植物进行免疫组织学检查。还通过电刺激评估移植物，以确定功能连接性。发现脊髓和骨骼肌移植物相互发挥营养作用，表现为在脊髓组织存在的情况下发育的骨骼肌移植物中有更大的肌肉质量，以及与骨骼肌移植物一起发育的脊髓移植物有更大的体积。免疫组织化学显示有NF阳性神经纤维离开脊髓移植物并进入肌肉组织。肌肉移植物中出现了AChE阳性终板。对双重移植物组合的脊髓部分进行电刺激通常会在肌肉联合移植物的特定区域引发收缩反应。这些结果证明了体内脊髓和骨骼肌组织移植物之间的结构和功能连接。成熟（成年）脊髓移植物与胎儿骨骼肌组织之间也建立了这种连接，这一事实表明，一些α运动神经元能够在眼内移植物中在没有合适靶标的情况下存活数月，并且它们能够随后支配骨骼肌靶标。
