| Fast oscillatory rhythm, which serves as an index for neuronal synchronization, been widely observed throughout many areas of the central nervous system (CNS). In the respiratory control system, fast oscillatory rhythm within inspiratory bursts are believed reflect an efficient balance between the central respiratory network and motoneuron drive which controls inspiratory muscles. It is well known that synaptic inhibition is critical for the generation of fast oscillatory rhythm. Likewise, it has been well established that the pontine brainstem region provides a potent inhibitory influence on respiratory drive. However, the role of synaptic inhibition on the generation of fast oscillatory rhythms within the respiratory control system is unknown and the contribution of the pontine to the generation of fast oscillations has never been described. For my dissertation, I investigated the role of synaptic inhibition in the generation and modulation of fast oscillatory rhythm recorded from phrenic nerve discharge in an arterially-perfused adult rat preparation. Alteration of central inhibitory inputs is achieved by perturbation or mechanical disruption. A broad range of data processing and analysis techniques are applied to characterize both linear and nonlinear characteristics of fast oscillatory dynamics. To quantitatively describe the effects of inhibitory synaptic transmission on these oscillatory dynamics, a mathematical model was developed and implemented. My results show that synaptic inhibition as well as influence from the pontine region involves a differential combination of linear and nonlinear interactions. With regard to effects of synaptic inhibition, different types of inhibitory have distinct roles in the modulation of fast oscillatory rhythm within the central respiratory network. |
