Habenular Nucleus Mediates Activities Of Dorsal Raphe In Sleep Apnea Syndrome

Sleep apnoea syndrome (SAS) is a disease of breath obstacle during sleep. With an increased risk of cardiovascular disease and stroke.people are paying more attention to it currently.Lee etc demonstrated that respiratory center had snaptic fiber connecting with Dorsal raphe nucleus and reticulopontine nucleus related to REM in 1995.A recent study shows that DR and 5-HT reduction is the main cause of OSA.However, little is known about the detail way and the function machanism..Habenula pay an important role in the center nerve system situating in epithalamus. The habenula, as the chief relay nucleus of the descending dorsal diencephalic system (consisting of stria medullaris, habenula and fasciculus retroflexus), is an important link between limbic and striatal forebrain and lower diencephalic and mesencephalic centers. It represents one of the major inputs in brain to the raphe nuclei and has anatomical and functional connections to modulate important functions such as sensory gating through thalamus, pain gating through central gray and raphe and motor stereotypies and reward mechanisms through substantia nigra and the ventral tegmental area. The habenula has been shown to play an important role in a diverse set of behavioural systems, which include olfaction, ingestion, mating, endocrine function.Habenula is the focus of many physiological function modulation.It can not only affect sleep but also modulate the cardiovascular,it can also promote stess-indueded hypertension.some study show that it can affect respiration.A lot of techonology such as ratio self-develop and immunochemistry show that efferents from the LHb form the main forebrain projection to the DRN and exert a functional inhibitory tone on neuronal activity. In turn, ascending 5-HT projections from the DRN can modulate stress responses in target forebrain regions that send outputs to the LHb.There are fiber connections between Hb and DR each other.To investigate the regulation activity of LHb and DRN,we performed the following: Electrical stimulation of DR caused an increase in respiratory rate and blood pressure . These phenomenon indicates that DR can modulate the respiratory movement and cardiovascular activity .DR can cause blood pressure increasing obviously through afferent fiber. Electric-stimulating DR exciting respiration maybe depend on the following two ways: one is the efferent fiber from DR projecting to hypoglossal nucleus,then increasing the respiratory rate by stimulating the activity of genioglossus.The other way may be related to the nervous fiber projecting to Habenula from DR,then complete the modulation of respiration by habenula. In order to explore if Hb affect the respiratory activity induced by electric-stimulating DR,We microinject lidocaine into habenula.conclutionly, the respiratory rate increasing effect induced by electric-stimulus obviously strengthen.However,injection lidocaine into habenula can decrease the bood pressure-increasing effect related to DR.All these show that Hb is the main nulei that exiting the respiration.DR modulating the repiratory function by injecting fiber to habenula and through the habenula.moreover, the inceasing blood pressure effect by stimulating DR is modulated by Hb. It has been reported that a lot of fibers in DR is efferent,and projecting to Hb .It is maybe related to 5-HT.We inject 5-HT into habenula,the respiratory rates and blood pressure increased. These can show that 5-HT is one of the...