Animals (including man) require the hippocampus for remembering places. The present exploratory research project will use novel split-brain strategies to investigate a region of the insect brain called the mushroom body (MB) - a functional analogue of the mammalian hippocampus. Previous research by the Principle Investigator' (PI) has shown that neuronal organization in the MBs is like that of the hippocampus and that the MBs are required for remembering places. The planned research, which is based on extensive information on structural, functional, and developmental attributes of MBs, speaks against orthodox opinion that these brain centers are olfactory analyzers storing olfactory data. Comparisons across species by the PI show that MBs process many types of sensations, as does the hippocampus. MBs will be used as models of the hippocampus to investigate changes that occur in neurons during the learning of a spatial task. The research is unique in that it compares the left and right MBs in a large insect species whose brain can be split before the experiment. Experiments test only one side of the brain using a spatial learning paradigm - associating the position of an image with an odor - perceived by the eye and the antenna of that side. The other "naive" side provides the control. The two sides are used to compare molecular, functional, and structural alterations associated with memory acquisition. This method will allow detection in specific neurons of proteins associated with learning and memory, using fluorescent antibodies. These neurons will be further investigated using recording methods and electron microscopy. Broader impacts of this research: 1) provides paradigmatic shift in our understanding of a learning and memory center; 2) generates data for engineering artificial neuromorphic memory circuits; 3) provides an accessible non-vertebrate model for undergraduate research training.
