ATP -a mediator of central chemoreception in brain stem

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Without a mechanical aid, it is impossible to stop breathing by will power. Why? Because the levels of CO2 in inspired air and in blood are an extremely powerful drive to breathe ?if these levels go up (as they would during self-willed asphyxiation or re-breathing from a plastic bag) we breathe more powerfully and rapidly. Specialized areas of the brain stem have long been known to detect CO2 in brain and relay this information to the neural networks that control breathing. Despite this, the detailed mechanisms of CO2 detection (chemoreception), and indeed the chemosensory cells themselves remain unknown. We have recently made a breakthrough in discovering that ATP is released from these specialized areas of the brain stem during elevated CO2 and is an essential link in the chemosensory reflex. We shall now exploit this finding by using experimentally simpler in vitro preparations of the brain stem. We shall look at the mechanisms of ATP release, as these will lead us to a fundamental understanding of the mechanisms of chemoreception. Thus we shall produce detailed maps of the locations of ATP release. We shall look at the characteristics of ATP release, which may highlight the types of cells that release ATP during elevated CO2. We shall identify the ion channels within the chemosensory cells responsible for detecting changes in CO2 and ultimately causing the release of ATP. Finally we shall examine release from of ATP from isolated cells in response to CO2 to allow us to identify them.