Physiological And Modelling Study Of Mechanisms Underling Neural Information Processing In Spinal Motor System

Mammalian central nervous system not only receive the regulation of endogenous neurotransmitters,but also process a large amount of exogenous regulatory information such as environmental changes and motor interventions.The regulatory mechanisms of the signaling pathways from the mesencephalic locomotor region to the spinal neurnal network are not fully understood,yet.Similarly,the endogenous mechanisms underlying the changes in excitability of spinal interneurons in the different training intensities remain poorly understood.There are still many important and unresolved problems in the research field of the neural information processing in the motor system,including:(1)How does the neurotransmitter acetylcholine regulate the excitability of brainstem serotonin(5-HT)neurons for processing and transmission of neural information?(2)How can the three-week treadmill training reshape and improve the signal processing capacity of the spinal cord motor system through the regulation of ionic channels and neurnal morphology?(3)What are the differences in the mechanisms on which the spinal cord motor system relies in information transmission and processing? To solve the above problems,we can explain the mechanism underlying neural information processing and regulation by the motor system in the perspective of the neurnal excitability,and explain the law of spinal cord motor system for exogenous information processing.Traditionally,studies of the above problems are usually limited to the neurophysiological experiments,but in this thesis I take the advantage of my research team for interdisciplinary research and study the problems with patch clamp technology and neural modeling.The main results are summarized as follows:(1)Based on the physiological experimental data,the models of 5-HT neurons in the brainstem and spinal lamina X neurons are completely constructed,from which the neural information simulation platform of the spinal cord motor system is established.(2)The acetylcholinergic mechanism underlying the signaling function of brainstem 5-HT neurons is explained,based on ionic channel PIC,and the key role of M receptor in neural information processing is revealed.(3)Through the verification of physiological experiment and model simulation results,this study explains the regulatory law of spinal nervous system by exercise intervention and reveals the mechanism of adaptive system based on PIC and neurnal morphology.(4)This study describes the different mechanisms by which different exercise intensity or strengthen rely on the spinal motor system to process external neural information.It also concludes that the effect of moderate intensity training on PIC and neuronal excitability is better than high intensity training.Simulation results further reveal the hidden channel mechanism: exercise training reshapes the nervous system by enhancing the conductance of Na-PIC and Ca-PIC or hyperpolarizing the activation of Na-PIC.