PDF(Pubmed)
Abstract：
Spinal cord injury (SCI) disrupts coordination between the bladder and the external urinary sphincter (EUS), leading to transient or permanent voiding impairment, which is more severe in males. Male versus female differences in spinal circuits related to the EUS as well as post-SCI rewiring are essential for understanding of sex-/gender-specific impairments and possible recovery mechanisms. To quantitatively assess differences between EUS circuits in males versus females and in spinal intact (SI) versus SCI animals, we retrogradely traced and counted EUS-related neurons. In transgenic ChAT-GFP mice, motoneurons (MNs), interneurons (INs), and propriospinal neurons (PPNs) were retrogradely trans-synaptically traced with PRV614-red fluorescent protein (RFP) injected into EUS. EUS-MNs in dorsolateral nucleus (DLN) were separated from other GFP+ MNs by tracing them with FluoroGold (FG). We found two morphologically distinct cell types in DLN: FG+ spindle-shaped bipolar (SB-MNs) and FG- rounded multipolar (RM-MNs) cholinergic cells. Number of MNs of both types in males was twice as large as in females. SCI caused a partial loss of MNs in all spinal nuclei. After SCI, males showed a fourfold rise in the number of RFP-labeled cells in retro-DLN (RDLN) innervating hind limbs. This suggests (a) an existence of direct synaptic interactions between spinal nuclei and (b) a post-SCI increase of non-specific inputs to EUS-MNs from other motor nuclei. Number of INs and PPNs deferred between males and females: In SI males, the numbers of INs and PPNs were ∼10 times larger than in SI females. SCI caused a twofold decrease of INs and PPNs in males but not in females.
摘要：
脊髓损伤（SCI）破坏膀胱和尿道外括约肌（EUS）之间的协调，导致暂时性或永久性排尿障碍，这在男性中更严重。与EUS相关的脊髓回路中的男性与女性差异以及SCI后的重新布线对于理解性别/性别特异性损伤和可能的恢复机制至关重要。为了定量评估男性与女性的EUS回路之间的差异，以及脊柱完整（SI）与SCI动物之间的差异，我们逆行追踪和计数EUS相关的神经元。在转基因ChAT-GFP小鼠中，运动神经元（MNs），中间神经元（INs），用注射到EUS中的PRV614-红色荧光蛋白（RFP）逆行跨突触追踪和本体脊髓神经元（PPN）。背外侧核(DLN)中的EUS-MN通过用荧光金(FG)示踪而与其他GFP+MN分离。我们在DLN中发现了两种形态上不同的细胞类型：FG纺锤形双极（SB-MNs）和FG圆形多极（RM-MNs）胆碱能细胞。男性中这两种类型的MN数量是女性的两倍。SCI导致所有脊髓核中的MNs部分丢失。SCI后，雄性在后DLN（RDLN）支配后肢中显示RFP标记的细胞数量增加了四倍。这表明（a）脊髓核之间存在直接的突触相互作用，（b）SCI后其他运动核对EUS-MN的非特异性输入增加。男性和女性之间递延的INs和PPNs数量：在SI男性中，INs和PPN的数量是SI女性的10倍。SCI导致男性的INs和PPNs减少两倍，而女性则没有。
