The Morphological Study On Connection Between Raphe Nuclei Of Medulla Oblongata And Vestibular Nuclei Complex And Its Function In Motion Sickness

Objective At present, it is believed that motion sickness happens in riding, navigation or aviation and is mostly induced by the abnormal activity of vestibular system. Signs and symptoms of motion sickness include headache, dizziness, and nausea, vomiting which influence remarkably the ability for navy or air members. Although there are many hypothesis for the pathogenesis, none of' them can thoroughly explain the occurrence, development and all kinds of symptoms in MS. The pathogenesis of MS is not clarificated. This study aims to observe the change of neurotrasmitter in the brain stem during motion sickness so as to render the foundation of the disease and investigate the relationship. The illumination of the mechanism has important academic and practical significance which to prevent and treat motion sickness. Materials and methods1. Establish and testify the MS model in rats. SD male rats were randomly divided into MS group and control group. We set up rat MS model using complex rotation stimulator made by our laboratory and gave rats one-hour stimulation everyday. The establishment of MS was measured by their kaolin consumption.2. After one-hour simulation, the changes of Fos protein expression in VNC and RNC of rats were observed by immunohistochemitry.3. TMR retrograde tracing technique was used to observe the position of stained positive cells in VNC.4. After injecting FG to the RNC, we used antibodies against SPR and Fos to testify the co-expression by immunofluorescence histochemistry in MVN. The stained sections were observed using a confocal laser-scanning microscope.Results1. Compared with the control group, the kaolin consumption of MS group increased markedly. The results indicated the establishment of MS in rats is successful.2. In the control group, we found the expression of Fos protein in cells of VNC and RNC were hardly observed. Compared with the control group, the number of Fos-positive cells increased markedly after the stimulation by complex rotation. The Fos protein were distributed in the different subnuclei of VNC and RNC. The results indicate that this stimulation can activate the vestibular neurons, some neurons in RNC were activated through direct or indirect connections with VNC.3. After injected TMR to the RMg,RPa,a number of TMR retrogradely labeled neurons were mainly distributed in the MVN,LVN and IVN. 4. The rats were stimulated after 6-day injection of FG, triple-labeled neurons of FG/Fos/SPR were found in MVN.Conclusion1. The motion sickness model in rats was established successfully.2. Fos protein were increased markedly in VNC and RNC by motion sickness model .This suggested that RNC play a role in MS.3. There are reciprocal connection between VNC and RNC in medulla oblongata.4. In the MVN, some neurons with Fos immunoreactivity transmitting the move information and projecting directly to the RNC might receive SPergic afferents.