NAME: Stephen Pennington
 

PROJECT TITLE: The functional distribution of dopamine in the crayfish CNS

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The LG (lateral giant) is a command neuron in the nervous system in a crayfish, that has the ability to trigger a characteristic response of a quick and powerful tail flip as a response to physical stimuli. The LG is able to distinguish between an attack and other non threatening stimuli. LG has been a popular research subject for cellular neurobiology, because the neuron is large and easy to identify in a preparation. Preliminary data suggest that dopamine inhibits the responses of LG, while serotonin enhances them. This project will form a part of a larger project that will address how the two neurotransmitters act together to shape LG's responses.

By locating possible release sites for neurotransmitters in relation to identified targets, it is possible to develop theories concerning how those neurotransmitters may be released and under what circumstances they may influence their targets. The aim of this project is to use immunolabeling techniques to identify neurons that contain dopamine and describe their location compared to the LG neuron. By doing this, it can be determined that dopamine may be released directly on the LG if neurons containing dopamine are found in close contact with LG, or that dopamine may target LG through a global signal if no direct contacts are found.

            In describing the location of dopamine in the crayfish CNS and then developing proposals about how dopamine may influence LG, we will contribute to understanding how dopamine may shape LG's responses in freely behaving crayfish. Furthermore, we may begin to understand how dopamine and serotonin may work together to shape neuron function and behavior.