Gil Krzysztof, Bugajski Andrzej, Skowron Beata, Thor Piotr
Department of Pathophysiology, Jagiellonian University Medical College, Kraków, Poland.
Folia Med Cracov. 2011;51(1-4):45-58.
Central nervous system receives information from the gut and modifies food intake mainly by vagus nerves. Some our data show that long-term electrical vagus nerve stimulation (VNS), which "mimics" satiety signal from gut, may cause reduction of body mass and decrease in food intake.
The purpose of this study was to assess the effects of chronic vagal stimulation on neurons in the nodose ganglions of vagus nerves, analyzed by c-Fos expression and image analysis.
Male Wistar rats (n = 24) were implanted with microstimulator (MS) and kept during the whole study (3 months) on high calorie diet. Sub-diaphragmatic left vagal nerve was stimulated by electrical rectangular pulses duration 10 ms, amplitude 200 mV, frequency 0.05 Hz generated by MS. Twelve rats (6--control and 6--MS implanted) were used for 3-week and 3-month experiments respectively. At the end of experiments the nodose ganglions of both vagus nerves (left and right) were taken, formalin fixed and paraffin-embedded specimens were made. The nodose ganglions neurons were identified by immunochemistry (PGP 9.5 as a marker) and the percentage of c-Fos positive neurons (anti c-Fos as a marker) were evaluated.
Assessment of c-Fos positive neurons in nodose ganglia of vagal nerve showed significant increase in percentage of positive cells in the left nodose ganglion (4.19%) and non significant in the right nodose ganglion (2.64 %) compared to control (1.44%) in 3-week experiment. Data obtained from 3-month experiment were similar: (4.97%; 2.66% and 1.68%) for left, right and control respectively. In both experiments number of c-Fos positive neurons was higher in left vagal ganglion compared to the right ganglion and control. There were no significant differences between 3-week and 3-month experimental groups.
Increase in c-Fos expression in left nodose ganglion neurons confirms the afferent transmission of the signal (generated by MS) from periphery to the brain by the vagal nerves.
中枢神经系统从肠道接收信息，并主要通过迷走神经调节食物摄入。我们的一些数据表明，长期电刺激迷走神经（VNS），即“模拟”来自肠道的饱腹感信号，可能会导致体重减轻和食物摄入量减少。
本研究旨在通过c-Fos表达和图像分析评估慢性迷走神经刺激对迷走神经结状神经节中神经元的影响。
雄性Wistar大鼠（n = 24）植入微刺激器（MS），并在整个研究期间（3个月）给予高热量饮食。由MS产生的持续时间为10毫秒、幅度为200毫伏、频率为0.05赫兹的矩形电脉冲刺激膈下左迷走神经。12只大鼠（6只作为对照，6只植入MS）分别用于3周和3个月的实验。实验结束时，取出双侧迷走神经（左、右）的结状神经节，用福尔马林固定并制成石蜡包埋标本。通过免疫化学（以PGP 9.5为标记）鉴定结状神经节神经元，并评估c-Fos阳性神经元的百分比（以抗c-Fos为标记）。
在3周实验中，与对照组（1.44%）相比，迷走神经结状神经节中c-Fos阳性神经元的评估显示，左结状神经节阳性细胞百分比显著增加（4.19%），右结状神经节阳性细胞百分比无显著增加（2.64%）。3个月实验获得的数据相似：左、右和对照组分别为（4.97%；2.66%和1.68%）。在两个实验中左迷走神经节中c-Fos阳性神经元的数量均高于右神经节和对照组。3周和3个月实验组之间无显著差异。
左结状神经节神经元中c-Fos表达的增加证实了由MS产生的信号通过迷走神经从外周向大脑的传入传递。
