Multitime Scale Analysis Of Bursting Activities In The Pre-B(?)tzinger Complex

Respiratory movement is a basic activity for maintaining the life of individuals.Abnormal respiratory rhythm caused by high temperature,disease or other special circumstances has plagued human life and threatened human health.To better understand the behaviors of the respiratory system,an important aspect is to know the dynamical mechanism of the respiratory rhythm,so that we can provide a theoretical basis for the control and treatment of abnormal respiratory rhythms.Within the pre-B(?)tzinger complex(lies in the rostral ventrolateral medulla of mammals),there are groups of inspiratory neurons that could autonomously emit spikes at a certain frequency,namely,the rhythmic bursting.Such bursting is believed to have close ties with the generation of respiratory rhythm.In this thesis,we investigate the effects of ion channels on the respiratory rhythm on basis of the pre-B(?)tzinger complex models.Using multi-time scale and bifurcation theories,we study the influences of different fast-slow ion channels on the bursting patterns considering both the single and coupled neural models.The main results of research are as follows:(1)We explore the influence of different slow timescales on the generation of somatic bursting solution in single cells.Our method is based on the fast-slow decomposition and two-parameter bifurcation analysis.We show how the bursting patterns are related to the mean level of excitatory input(gtonic-e)and the maximal conductance associated with the sodium(gNa)by treating the gating variables n and h as a slow variable respectively.(2)Based on coupled complex cells,we investigate the influences of different Vsyn-e values on the bursting patterns.In anti-phase case,there are mixed bursting dynamics.