Mapping of spinal interneurons involved in regulation of the lower urinary tract in juvenile male rats
Mapping of spinal interneurons involved in regulation of the lower urinary tract in juvenile male rats
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DOI：
10.1016/j.ibror.2020.07.002
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发表时间：
2020-12-01
期刊：
影响因子：
2.6
通讯作者：
De Groat, W. C.
中科院分区：
文献类型：
--
作者：
Karnup, S., V;De Groat, W. C.
膀胱（BL）和尿道外括约肌（EUS）之间的协调对于尿液的储存和排泄是必要的。在大鼠中，在脊髓的两个水平（即，L 6-S1和L3-L4）在这种协调中发挥重要作用。在本实验中，伪狂犬病病毒（PRV）编码的荧光标记（GFP和RFP）的逆行跨突触转运被用来跟踪这些电路。为了检查EUS相关和BL相关的神经元间群体的相对定位，我们将PRV-GFP注射到EUS中，将PRV-RFP注射到BL壁中。PRV感染的脊髓中间神经元群体主要位于L 6/S1的背连合（DCM）和中央管（CC）上方和侧面的L3/L4的假设的腰椎协调中心（LSCC）中。在这两个网站共定位的标记发生在大量的标记的interneurons，表明伴随参与这些双标记的神经元在EUS和BL电路，并建议他们的作用，在EUS-BL协调。在两个位点的细胞亚群中检测到强烈的GFP或RFP荧光，表明它们被感染较早，因此可能代表与输出神经元直接突触的一级初级中间神经元。还鉴定了可能代表二级中间神经元的大量弱荧光神经元。在EUS相关的一级中间神经元的群体中，仅3- 8%表现出对GABA能和甘氨酸能抑制性神经元特异性的早期转录因子Pax 2的阳性免疫反应，这表明DCM和LSCC中直接投射到EUS运动神经元的中间神经元中的大多数是兴奋性的。
Coordination between the urinary bladder (BL) and external urethral sphincter (EUS) is necessary for storage and elimination of urine. In rats interneuronal circuits at two levels of the spinal cord (i.e., L6-S1 and L3-L4) play an important role in this coordination. In the present experiments retrograde trans-synaptic transport of pseudorabies virus (PRV) encoding fluorescent markers (GFP and RFP) was used to trace these circuits. To examine the relative localization of EUS-related and BL-related interneuronal populations we injected PRV-GFP into the EUS and PRV-RFP into the BL wall. The PRV infected populations of spinal interneurons were localized primarily in the dorsal commissure (DCM) of L6/S1 and in a hypothesized lumbar spinal coordinating center (LSCC) in L3/L4 above and lateral to central canal (CC). At both sites colocalization of markers occurred in a substantial number of labeled interneurons indicating concomitant involvement of these double-labelled neurons in the EUS- and BL-circuits and suggesting their role in EUS-BL coordination. Intense GFP or RFP fluorescent was detected in a subpopulation of cells at both sites suggesting that they were infected earlier and therefore likely to represent first order, primary interneurons that directly synapse with output neurons. Larger numbers of weakly fluorescent neurons that likely represent second order interneurons were also identified. Within the population of EUS-related first order interneurons only 3-8 % exhibited positive immunoreaction for an early transcription factor Pax2 specific to GABAergic and glycinergic inhibitory neurons suggesting that the majority of interneurons in DCM and LSCC projecting directly to the EUS motoneurons are excitatory.