论文部分内容阅读
本实验室以往整体水平的工作表明,而神经后核内侧区(the medial area of nucleus retrofacialis,mNRF)在呼吸节律发生中具有关键的作用.近期在新生大鼠离体脑干-脊髓标本上进行的连续切割实验表明包含mNRF的从闩水平至闩前500μm的延髓腹侧半的结构在呼吸节律发生中作用至关重要.本实验采用新生SD大鼠(0～3天),雌雄不拘.乙醚麻醉后制作离休延髓-颈髓标本,用玻璃吸附电极记录颈4或颈5腹根(C_(4v),C_(5v))的节律性吸气样放电(the rhythmic inspiratory-like discharges,RIDs)作为呼吸活动的监测指标.通过红藻氨酸(kainic acid,KA)局部化学损毁双侧mNRF,观察其对RIDs的影响,以进一步证实mNRF是延髓基本呼吸节律发生的部位.结果显示:(1)在正常灌流情况下,RIDs节律较整齐,可稳定记录4～6h;(2)局部微量注射KA(1.17mmol/L,0.25μl/侧)损毁双侧mNRF,RIDs不可逆地消失,而呈癫痫样发放;只损毁对侧mNRF,RIDs略减弱,但不消失,再损毁双侧mNRF,RIDs则不可逆地消失,代之为癫痫样发放;损毁双侧对照区域,RISs无显著性变化.组织学检查证实损毁区域为mWRF.KA为谷氨酸结构类似物,过量KA对受体的过度刺激将引起神经元急性死亡.KA毒性作用的显著特点是只损伤局部神经元胞体而不损伤传入纤维末梢,过路纤维和其
Our previous overall level of work demonstrated that the medial area of the nucleus retrofacialis (mNRF) plays a key role in the development of respiratory rhythm and has recently been performed on isolated brainstem-spinal cord specimens of neonatal rats The results of continuous cutting experiments showed that the structure of ventral half of medulla oblongata including mNRF from the level of latch to 500 μm in front of the latch is very important in the occurrence of respiratory rhythm.The newborn SD rats (0-3 days) After anesthesia, the medulla oblongata - cervical spinal cord specimens were made and the rhythmic inspiratory - like discharges (RIDs) of the cervical 4 or 5 ventral roots (C_ (4v), C_ (5v) As a monitoring index of respiratory activity.Main local damage of mNRF by kainic acid (KA) was observed and its effect on RIDs was observed to further confirm that mNRF is the site of basic respiratory rhythm of medulla oblongata.The results showed that: (1 ) Under normal perfusion, the rhythms of RIDs were relatively stable and could be stably recorded for 4 ~ 6h. (2) Local microinjection of KA (1.17mmol / L, 0.25μl / side) destroyed the bilateral mNRF and RIDs irreversibly disappeared, Like release; only contralateral mNRF is damaged, RIDs slightly reduced , But did not disappear, and then damaged both sides of mNRF, RIDs irreversibly disappear, replaced by epileptogenic delivery; damaged bilateral control area, RISs no significant change.Histological examination confirmed that the damaged area mWRF.KA glutamate Structural analogues, over-stimulation of receptors by excessive KA, will cause acute death of neurons A striking feature of the toxic effects of KA is that it damages only local neuronal soma without damaging afferent fiber tips, crossover fibers and their