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The Role Of Astrocyte And Purinergic Signaling In Rtn Chemoreception, Ian C. Wenker

Doctoral Dissertations

Central chemoreception is the mechanism by which the brain regulates breathing in response to changes in tissue pH/CO2. It is particularly important during sleep and its disruption has been associated with certain pathologies, including central sleep apnea and central congenital hypoventilation syndrome. A region of the brainstem called the retrotrapezoid nucleus (RTN) is thought to be an important site of central chemoreception. Recent evidence suggests that RTN chemoreception involves two mechanisms. The first appears to be H+-mediated activation of neurons via inhibition of pH-sensitive potassium channels. More recently, a second sensing mechanism has been identified; paracrine release of ATP in …

Inorganic Carbon And Nitrogen Utilization In Mixotrophic Ciliates, Donald M. Schoener

Doctoral Dissertations

Mixotrophy is a common nutritional strategy that uses both heterotrophy and photosynthesis. Kleptoplastidic mixotrophs do not make their own plastids but acquire them from their algal prey. Before we can add mixotrophs to standard ecological models we need to understand how much each nutritional mode contributes to mixotrophic growth, and how this balance may be influenced by plastid acquisition, retention, and turnover.

In order to examine the role of captured chloroplasts in the metabolism of the oligotrich ciliate Strombidium rassoulzadegani. I evaluated the uptake and retention of chloroplasts, the ability of two different algae to supply functional chloroplasts, and …