Dissociation of the effects of nucleus raphe obscurus or rostral ventrolateral medulla lesions on eliminatory and sexual reflexes.
Dissociation of the effects of nucleus raphe obscurus or rostral ventrolateral medulla lesions on eliminatory and sexual reflexes.
复制标题
中缝暗核或延髓腹外侧病变对消除反射和性反射影响的分离。
DOI：
10.1016/s0031-9384(01)00631-x
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发表时间：
2002
影响因子：
2.9
通讯作者：
Beattie,MS
中科院分区：
文献类型：
--
作者：
Holmes,GM;Hermann,GE;Rogers,RC;Bresnahan,JC;Beattie,MS
采用大鼠标本，观察电解损毁中缝暗核(NRO)或延髓吻端腹外侧部后，肛门外括约肌(EAS)收缩和反射性阴茎勃起的长期变化。用5 mm探头扩张EAS后进行肌电(EAS-EMG)测量。阴茎勃起采用标准的前联结反射测试范式进行测量。在损伤后48小时，100%的NRO损毁动物表现出反射性勃起，损毁动物EAS肌电的幅度明显大于假手术对照组。这些结果提示EAS在破坏NRO后出现反射亢进。到损伤后14天，NRO损伤动物的EAS反应性已恢复到与非损伤动物相当的水平。NRO损伤不影响阴茎勃起的测量。在巨细胞核(GI)和巨细胞旁外侧核(GI-LPGi)损毁的动物中，在任何时间点都没有观察到明显的EAS反射变化。术后48h，GI-LPGi损伤组与对照组相比，首次勃起潜伏期显著缩短，勃起次数显著增加。在损伤后14天观察到类似的勃起潜伏期的易化，而勃起次数和翻转总数不再与对照组有显著差异。这些和以前的研究表明，NRO调节大鼠的排便反射。这些数据进一步表明，合并的EAS和球脊神经(BS)运动神经元受离散和独立的脑干回路控制，脊髓损伤后EAS和阴茎反射的增加是通过失去不同的下行输入来调节的。
Rat preparations were used to investigate long-term changes in external anal sphincter (EAS) contractions and reflexive penile erection following electrolytic lesions of the nucleus raphe obscurus (nRO) or the rostral ventrolateral medulla. EAS contractions were measured electromyographically (EAS EMG) following distention of the EAS with a 5-mm probe. Penile erections were measured using a standard ex copula reflex testing paradigm. At 48 h postlesion, 100% of nRO-lesioned animals displayed reflexive erections and the magnitude of EAS EMG was significantly greater in lesioned animals than in sham controls. These results suggested EAS hyperreflexia following destruction of the nRO. By 14 days postlesion, EAS responsiveness in nRO-lesioned animals had returned to levels comparable to nonlesioned animals. No measures of penile erection were affected by nRO lesions. In animals with nucleus gigantocellularis (Gi) and lateral nucleus paragigantocellularis (Gi-lPGi) lesions, no significant changes to EAS reflexes were observed at any time point. At 48 h postoperative, Gi-lPGi lesions significantly reduced the latency to first erection and increased the number of erections elicited relative to controls. Similar facilitation of erection latency was observed at 14 days postlesion, while erection number and flip total were no longer significantly different from controls. These and previous studies suggest that the nRO regulates defecatory reflexes in the rat. These data further suggest that the comingled EAS and bulbospongiosus (BS) motoneurons are controlled by discrete and separate brainstem circuits and that increases in EAS and penile reflexes after spinal cord lesions are mediated by loss of different descending inputs.