Hamilton Sophomore Investigating Role of Neurotransmitter in Metamorphosis

Anna Arnold is one of a select few Hamilton College science students chosen to participate in the school's summer science research program. This opportunity requires the committment of ten summer weeks to a partnership with a Hamilton professor, carrying out laboratory and field work on a specific project. Arnold is concentrating on Assistant Professor of Biology Herman Lehman's specialty, insect neurotransmitters. Anna is studying octopamine, an insect chemical messenger about which little is known. Her primary interest is the relationship between octopamine levels and the production and expression of steroid hormones in the moth Manduca sexta. In order to address this issue, Arnold is attempting to determine where and when the steroid receptors appear in the nerve cord, an early evolutionary precursor to our spinal cord, throughout metamorphosis. By using a technique known as "immunocytochemistry," which provides evidence for the presence of chemicals through recognizing and staining them, Anna will be able to gather data that will prove critical in her research. This topic of inquiry is important not only because it will help to characterize a relatively new neurotransmitter, but also because it may provide information about the evolutionary path that insects have taken. Octopamine is similar in structure to the human neurotransmitter dopamine, although the two carry out vastly different functions. It will be of interest to gain information on the role that changing octopamine levels play throughout the development of insects and to contrast this chemical with neurotransmitters that function in human development