Miller K E, Douglas V D, Richards A B, Chandler M J, Foreman R D
Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City 73190, USA.
Brain Res Bull. 1998 Sep 1;47(1):43-7. doi: 10.1016/s0361-9230(98)00065-3.
Physiological studies indicate that neurons in the upper cervical spinal cord have descending projections to the lumbosacral spinal cord and mediate inhibition of dorsal horn neurons activated from afferent input. In the present study, retrograde tracing techniques were used to examine the distribution of propriospinal neurons in C1-C2 spinal segments that project to lumbosacral spinal segments. Fluorogold or horseradish peroxidase were injected unilaterally or bilaterally into the L5-S1 spinal segments. After 2-4 days, rats were perfused with fixative and C1-C2 spinal segments were processed for retrograde labeling. Numerous neurons were found in the C1-C2 segments. In unilaterally and bilaterally injected rats, retrogradely labeled neurons were located on both the ipsilateral and contralateral sides. Retrogradely labeled neurons were located in the following locations: lateral cervical and spinal nuclei, nucleus proprius, ventral horn and the central gray region (area X). These studies demonstrate a descending projection from C1-C2 segments to the lower lumbar and sacral spinal cord. We hypothesize that many of these C1-C2 propriospinal neurons are important in modulating responses of spinal neurons at lower segmental levels to various peripheral stimuli.
生理学研究表明，颈上脊髓中的神经元具有下行投射至腰骶脊髓，并介导对由传入输入激活的背角神经元的抑制作用。在本研究中，采用逆行追踪技术来检查C1 - C2脊髓节段中投射至腰骶脊髓节段的脊髓固有神经元的分布。将荧光金或辣根过氧化物酶单侧或双侧注入L5 - S1脊髓节段。2 - 4天后，用固定剂灌注大鼠，并对C1 - C2脊髓节段进行逆行标记处理。在C1 - C2节段发现了大量神经元。在单侧和双侧注射的大鼠中，逆行标记的神经元位于同侧和对侧。逆行标记的神经元位于以下部位：外侧颈核和脊髓核、固有核、腹角和中央灰质区域（X区）。这些研究证明了从C1 - C2节段到下腰和骶脊髓的下行投射。我们推测，这些C1 - C2脊髓固有神经元中的许多在调节较低节段水平的脊髓神经元对各种外周刺激的反应中起重要作用。
