大鼠视上核与延髓头端腹外侧区心血管相关神经元间的功能联系

发布时间：2018-01-09 12:01

本文关键词：大鼠视上核与延髓头端腹外侧区心血管相关神经元间的功能联系　出处：《皖南医学院》2017年硕士论文　论文类型：学位论文

【摘要】：目的:在麻醉大鼠,观察刺激视上核(supraoptic nucleus,SON)前后,延髓头端腹外侧区(rostral ventrolateral medulla,RVLM)神经元单位放电以及外周生理指标的变化,探讨SON和RVLM神经元之间是否存在直接或间接的功能联系,再进一步分析SON与RVLM间血管升压素(vasopressin,VP)联系的可能性,为阐明心血管功能的中枢调节机制提供新的理论依据。方法:取250~300g健康成年雄性SD大鼠,腹腔注射氨基甲酸乙酯(700mg/kg)和α-氯醛糖(35 mg/kg)混合麻药麻醉后,固定于脑立体定位仪,采用Powerlab多通道记录系统以及A-M Systems的刺激器和放大器系统,进行大鼠RVLM神经元单位放电、股动脉血压、心电图、呼吸肌肌电以及体温的同步记录。然后将金属刺激电极置于SON核团处,观察电刺激SON前后RVLM神经元单位放电以及其它外周指标的变化,分析SON与RVLM间是否存在功能联系。在RVLM核团微量注射VP受体(V1a受体)阻断剂SR49059,观察注射SR49059前后,电刺激SON,RVLM神经元单位放电及外周指标的改变,以进一步分析SON与RVLM间VP联系的可能性。结果:1.心血管中枢与心血管功能的同步记录技术:在18只大鼠共记录到23个RVLM神经元自发单位放电,其中有16个是连续性放电型式,7个是周期性簇状放电型式。两种类型放电分别对应的同步记录指标进行组间比较,RVLM放电频率、RVLM放电幅值、心率变异性(heart rate variability,HRV)(LF/HF)、心率、体温、收缩压、舒张压、平均动脉压以及呼吸肌肌电频率均无统计学差异,仅呼吸肌肌电幅值变化有统计学意义(P0.05)。血压升高时,观察到RVLM神经元单位放电明显被抑制;针刺大鼠尾部引起RVLM神经元放电活动出现变化,从而使外周各指标也发生相应改变。2.电刺激SON对RVLM神经元单位放电及外周指标的影响:在18只SD大鼠共记录到19个RVLM神经元单位放电。刺激(200μA,0.2ms,100Hz,0.2s)SON后,观察到10个RVLM神经元单位放电频率显著下降(P0.05),放电幅值下降,相应的平均动脉压上升(P0.05),心率、呼吸频率均有下降趋势;9个神经元单位放电频率显著升高(P0.05),其它指标变化不显著。3.RVLM核团微量注射SR49059的作用:在RVLM注射SR49059预处理前,对SON的200μA电刺激在9个RVLM神经元观察到单位放电频率显著下降(P0.05),单位放电幅值下降,心率呈下降趋势。在SR49059预处理后,观察到RVLM神经元单位放电频率和幅值均呈上升趋势,其它外周指标分析均无统计学差异;在注入SR49059立即电刺激SON,观察到各项指标无显著变化;在注入SR49059稳定10min后电刺激SON,观察到RVLM神经元单位放电频率和幅值无明显下降,其他指标亦未见显著变化。对SON进行400μA电刺激后,也观察到RVLM神经元单位放电频率和幅值呈下降趋势;心率、LF/HF呈下降趋势。同样,RVLM注射SR49059预处理后,RVLM神经元单位放电频率和幅值均呈上升趋势,其它外周指标分析均无统计学差异;在注入SR49059后立即电刺激SON,各项指标分析均无统计学差异;在注入SR49059稳定10min后电刺激SON,RVLM神经元单位放电频率和幅值呈下降趋势,其他指标未见显著变化。结论:(1)所建立的心血管中枢神经元单位放电和外周生理指标的同步记录技术,适用于观察心血管各级中枢之间的相互作用,以及心血管中枢与心血管外周活动之间的相互影响。(2)电刺激SON,对RVLM不同心血管相关神经元作用不同,表现为抑制或兴奋作用,并伴有外周指标的相应改变,提示SON与RVLM间存在直接或间接功能联系的可能性,且对心血管活动有一定的调节作用。(3)RVLM核团微量注射VP受体阻断剂SR49059后,电刺激SON后RVLM神经元放电活动抑制作用减弱,提示VP可能参与该通路功能联系。
[Abstract]:Objective: in anesthetized rats, observe the stimulation of supraoptic nucleus (supraoptic, nucleus, SON) and the rostral ventrolateral medulla (rostral ventrolateral, medulla, RVLM) change the unit discharges of neurons and peripheral physiological indexes, discuss whether there is direct or indirect links between SON and RVLM neurons, and further analysis of SON RVLM vasopressin (vasopressin, VP) with the possibility of providing a new theoretical basis for clarifying central cardiovascular function regulation mechanism. Methods: 250~300g healthy adult male SD rats by intraperitoneal injection of urethane (700mg/kg) and alpha chloralose (35 mg/kg) mixed anesthesia after anesthesia, fixed in the brain stereotaxic apparatus, using Powerlab multi channel recording system and A-M Systems stimulator and amplifier system of neurons in rat RVLM, femoral arterial blood pressure, ECG, respiratory muscle and body temperature The synchronous record. Then the metal will stimulate electrodes placed on the SON nucleus, SON changes before and after the unit discharge of RVLM neurons and other indicators of the observation of peripheral electrical stimulation, analysis of SON and RVLM between the existence of functional connections. In the RVLM nucleus microinjection of VP receptor (V1a receptor) blocker SR49059, observed before and after SR49059 injection, electric SON stimulation, unit discharge of RVLM neurons and peripheral index changes, to further analysis of SON between RVLM and VP. Results: the possibility of contact recording technique to 1. central cardiovascular and cardiovascular function in 18 rats were recorded 23 RVLM spontaneous unit discharge, 16 of which are continuous discharge type 7, is a periodic burst discharge type. Comparison of two types of discharge index recorded respectively between the groups, the discharge frequency of RVLM, RVLM discharge amplitude, heart rate variability (heart rate, variability, HRV) (LF/HF), Heart rate, body temperature, systolic blood pressure, diastolic blood pressure, there was no significant difference in mean arterial pressure and respiratory muscle EMG frequency, only respiratory muscle EMG amplitude change was statistically significant (P0.05). Blood pressure, observed the unit discharge of RVLM neurons were inhibited obviously by acupuncture; rat tail caused changes in firing of RVLM neurons, which the peripheral indicators of the impact on the change of.2. SON stimulation on unit discharges of RVLM neurons and peripheral index: 18 SD rats were recorded to discharge 19 RVLM neurons. Stimulation (200 A, 0.2ms, 100Hz, SON, 0.2S) were significantly decreased to the discharge rate of 10 RVLM neurons (P0.05), discharge amplitude decreased, the mean arterial pressure increased accordingly (P0.05), heart rate, respiratory rate decreased; the discharge frequency of 9 units increased significantly (P0.05), the other indexes did not change significantly.3.RVLM nucleus trace The role of SR49059 in RVLM injection: the injection of SR49059 before the pretreatment of 200 A electric stimulation, SON to the unit discharge were observed in 9 neurons in the RVLM frequency decreased significantly (P0.05), the unit discharge amplitude decreased, heart rate decreased in SR49059. After the pretreatment, the observed frequency and amplitude of unit discharge of RVLM neurons were the rise, other peripheral indexes were not statistically significant; the SR49059 injection in the electrical stimulation of the SON immediately, observed no significant changes in the indicators; SR49059 injection in the SON stable 10min after electrical stimulation, unit discharge of RVLM neurons observed frequency and amplitude decreased significantly, there was no significant changes in other indicators of 400 A. Electrical stimulation of the SON, also observed the frequency and amplitude of unit discharge of RVLM neurons was decreased; heart rate, LF/HF decreased. Similarly, RVLM injection after pretreatment with SR49059, a single RVLM neuron discharge frequency and amplitude Showed an upward trend, other peripheral index analysis showed no significant differences; in the injection of SR49059 immediately after SON stimulation, there was no significant difference in each index analysis; SR49059 SON injection stimulation stable after 10min, the frequency and amplitude of unit discharge of RVLM neurons decreased, other indexes had no significant changes. Conclusion: (1) the technique of simultaneous recording discharge and peripheral physiological indexes of neurons cardiovascular center established, the interaction between observation for cardiovascular center at all levels, the mutual influence between central and peripheral cardiovascular and cardiovascular activities. (2) the electrical stimulation of SON, different RVLM of different cardiovascular related neurons showed inhibitory or excitatory effect. The corresponding change, accompanied by peripheral index, suggesting the existence of possibility of direct or indirect connections between RVLM and SON function, and has a certain role in the regulation of cardiovascular activity. (3) RV After microinjection of VP receptor blocker SR49059 in the LM nucleus, the inhibitory effect of RVLM neuron discharge activity was weakened after the electrical stimulation of SON, suggesting that VP may be involved in the function of the pathway.

【学位授予单位】：皖南医学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R33

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