The human brain remains one of the great mysteries to modern science. A further understanding of the function of the brain has great implications both for how we understand ourselves as well as how we might design modern computational devices. Perhaps the greatest obstacle towards understanding the brain is the vast number and complexity of its component unit cells, or neurons. Current cellular and imaging tools have now advanced to the point where it might now be possible to build complete maps of relatively simple brains, such as that of the fruit fly. This project will support the training and efforts of a team of students who will help assemble the first complete neuron-scale set of structures for a part of the fly brain. Using high-resolution images of individual neurons, the structures of each cell will be determined, and using sophisticated computational tools a complete digital map will be assembled. This map can be used to develop simulations of regional brain function as well as to develop ideas for how complex brains are structured. Experience from this project will pave the way for developing methods to automate the mapping of brains. Finally, a team of students, from high school to graduate level will receive training in modern neuroscience.
The aim of this project was to categorize all neurons of fruit fly larval ventral nerve cord. The function of the central nervous system (CNS) is based on the structure of its constituent neurons. So for instance, in the human spinal cord, there are interneurons that coordinate movements between each hand so you can clap or perform other tasks that require cooperative planning. These interneurons should have dual cellular processes in regions that plan the movements for each hand. However, the vertebrate spinal cord is extremely complex and it would be at present difficult to identify such interneurons let alone test their function. The ventral nerve cord of the fly CNS is the equivalent of the spinal cord and is responsible for coordinating crawling in the larva. Through efforts of the Condron lab in this proposal as well as a team of scientists at the Howard Hughes Janelia Farm Research Center, all or most of the interneurons of the larval ventral cord have been identified. This now puts us in a position to describe entire circuit for each kind of movement. While it will likely be many years before these circuits are understood, their initial characterization as part of this project is the first critical step. For instance, we can see interneurons that have the right structure to coordinate movements on each side. These can now be tested experimentally and will have broad implications for how we understand the CNS function as well as future pre-clinical applications in the mouse. The work for this proposal was mostly carried out by a team of undergraduates, many of whom got to experience Janelia Farm. Therefore, this had a very high impact on training of future scientists, including underrepresented minorities.
