Dynamic Research On Dendritic Mixed Bursting In The Pre-B(?)tzinger Complex

Respiratory movement is a crucial physiological activity for mammals to maintain individual life,which contains abundant rhythmic behaviors.Researches suggest that the pre-B(?)tzinger complex(pre-B(?)tC)in the ventrolateral medulla of mammals is the center for the generation and regulation of respiratory rhythm.There exist a special class of neurons,which produce rhythmic firing activities individually or jointly through synaptic coupling.And these electrical behaviors are closely related to the generation of respiratory rhythm.Biological experiments have reported a special bursting pattern,mixed bursting(MB),which is characterized by two or more different types of short bursts in one periodic cycle.Through further theoretical studies,investigators studied specific neural model and believed that MB depends on the joint action of persistent sodium current(I_NaP)and intracellular calcium oscillations.In this thesis,we study the firing activity of single neuron,based on the inspiratory single-compartment model established by Park and Rubin.We numerically find that MB could also be driven by the sole action of the calcium oscillations which arise from the dendritic subsystem.We call this mixed bursting pattern as dendritic mixed bursting(DMB).The thesis contains five chapters.The first section is the introduction,including the research background,recent researches,analytical methods and the structure of the thesis.The second part involves some knowledge of the nervous system and dynamic system concerned with this study.The third part displays several interesting dendritic mixed bursting(DMB)in the pre-B(?)tC based on different ion conductance,and we discuss the underlying dynamics by kinetic methods in details.Moreover,the effect of g_CAN on DMB pattern is detected.In chapter.4,we consider the effect of electromagnetic induction and explore the transition of electrical patterns within DMB rhythms,by changing the influence of magnetic current on membrane potential.The transition from sigh-like bursting to eupnea bursting is observed,which is in good agreement with biological experiments.In addition,more complex types of DMB,which has never been studied,are presented under the external direct current.The last chapter is the summary and prospect.This thesis not only enriches the understanding of the mixed bursting modes,but also provides a new idea to integrate the dynamics of irregular discharge in pre-B(?)tC.