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The Functional Effects Of Barium And Hypoxia On The In Vitro Respiratory Activity, Gaofeng Xu
The Functional Effects Of Barium And Hypoxia On The In Vitro Respiratory Activity, Gaofeng Xu
Theses
The hypoxic respiratory response in mammals consists of a transit increase in the respiratory frequency (augmentation phase) followed by a decrease in frequency (depression phase). To understand how the central respiratory system contributes to this response, the in vitro transverse brainstem slice model is used, which contains the pre-Bötzinger Complex, which is responsible for respiratory rhythm generation. The in vitro experiments performed for this thesis provide evidence that external barium exposure alters respiratory activity and significantly increases (P<0.00 1) the voltage of tonic activity under control oxygen conditions (95% FO2). During severe hypoxia (0% FO2), respiratory tonic activity is significantly elevatedduring the depression phase (from 0.55 to 0.95, n=6, P<0.001) by external barium, presumablydue to the closing of K+ channels and a reduction in K+ conductance.
The Effects Of Theophylline On The In Vitro Respiratory Response To Hypoxia, Ke Geng
The Effects Of Theophylline On The In Vitro Respiratory Response To Hypoxia, Ke Geng
Theses
The isolated transverse brainstem slice preparation of neonatal mice is employed to investigate the function of theophylline, a competitive nonselective phophodiesterase inhibitor and adenosine receptor antagonist, on the hypoxic ventilatory response. Brainstem slices are isolated from neonatal mice (4-8 days old) and superfused with artificial cerebrospinal fluid (aCSF), equilibrated with a hyperoxic gas mixture (95% O2, 5% CO2) as a control, and anoxic mixture (0% O2, 5% CO2, 95% N2) to create severe hypoxia at the tissue level. Using suction electrodes, extracellular population activities of respiratory neurons is recorded from …