Increased spinal expression of c-Fos following stimulation of the lower urinary tract in chronic spinal cord-injured rats
Increased spinal expression of c-Fos following stimulation of the lower urinary tract in chronic spinal cord-injured rats
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DOI：
10.1007/s004180050392
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发表时间：
1999-07-01
影响因子：
2.3
通讯作者：
Mense, S
中科院分区：
文献类型：
--
作者：
Callsen-Cencic, P;Mense, S
c-Fos的表达进行了研究，在腰和骶脊髓区域参与处理传入输入从下尿路和比较脊髓损伤（SCI）的动物和对照动物与完整的神经轴。从下尿路传入途径被激活，通过插入导管通过尿道进入膀胱或通过导管插入加上膀胱内生理盐水输注诱导反射性排尿收缩。单独放置一个导管引起Fos的表达在类似数量的神经元在SCI和对照组大鼠主要是在内侧背角（MDH）和背连合（DCM）的节段L1-2和L5-S1的最大值在L5。额外的生理盐水输注诱导低频率，高振幅，有节奏的膀胱收缩的持续时间长的大鼠与完整的脊髓，而在SCI大鼠，膀胱扩张引起反射性收缩在更高的频率，更小的振幅和更短的持续时间。然而，基础和平均膀胱压力，以及总收缩时间相对于整个记录时间，没有显着差异。扩张引起的膀胱收缩显着增加Fos的表达主要在脊髓节段L5-S1在对照组大鼠，其中大多数膀胱和尿道传入纤维终止。Fos阳性细胞分布于MDH、LDH、DCM和V-VII层外侧。与对照组相比，脊髓损伤（SCI）后的Fos表达发生在一个显着更多的神经元在整个节段L3-S1诱导膀胱反射。Fos阳性细胞数量的最大比例增加发生在L3-5中，L3-5通常只接受来自膀胱的少量传入输入。LDH和外侧板V-VII中的细胞数量主要增加。这些数据与SCI后脊髓通路的神经可塑性重组的概念一致。沉默的突触或形成新的连接的传入轴突发芽尾部的病变，从膀胱扩张后表达Fos的细胞数量增加明显，可能是反射性排尿的出现在慢性SCI大鼠的潜在因素。
c-Fos expression was studied in the lumbar and sacral spinal cord regions involved in processing afferent input from the lower urinary tract and a comparison was made between spinal cord-injured (SCI) animals and control animals with intact neuraxes. Afferent pathways from the lower urinary tract were activated either by insertion of a catheter through the urethra into the urinary bladder or by catheterisation plus induction of reflex micturition contractions by intravesical saline infusion. Placement of a catheter alone elicited Fos expression in a similar number of neurones in SCI and control rats mainly in the medial dorsal horn (MDH) and dorsal commissure (DCM) in the segments L1-2 and L5-S1 with a maximum in L5. Additional saline infusion induced low-frequency, high-amplitude, rhythmic bladder contractions of long duration in the rats with intact spinal cords, whereas in SCI rats, bladder distension elicited reflex contractions at a higher frequency, smaller amplitude and shorter duration. However, the basal and mean bladder pressure, as well as the total contraction time relative to the whole recording time, was not significantly different. Distension-induced bladder contractions markedly increased Fos expression primarily in the spinal segments L5-S1 in the control rats, where the majority of bladder and urethral afferent fibres terminates. Fos-positive cells were located in the MDH, lateral dorsal horn (LDH), DCM and the lateral aspect of laminae V-VII. Compared to controls, Fos expression after spinal cord injury (SCI) occurred in a significantly greater number of neurones throughout the segments L3-S1 following induction of bladder reflexes. The greatest proportional increase in the number of Fos-positive cells occurred in L3-5 which normally receive only little afferent input from the urinary bladder. Cell numbers predominantly increased in the LDH and lateral lamina V-VII. The data are consistent with the concept of a neuroplastic reorganisation of spinal pathways after SCI. Unmasking of silent synapses or formation of new connections by afferent axonal sprouting caudal to the lesion, as evident from the increased numbers of cells expressing Fos after bladder distension, could be factors underlying the emergence of reflexogenic micturition in chronic SCI rats.