This research project will uncover neuronal network mechanisms that allow animals to recognize, and learn to recognize, different odors in their dynamic environment. The early stages of the hawkmoth Manduca sexta's olfactory system generate odor-specific responses which are spatiotemporally complex. Electrophysiological experiments, in conjunction with conditioning trials, will be carried out to determine which features of the complex response are in fact relevant to the moth's adaptive encoding of its olfactory environment, and how these features are resculpted when the moth learns to appreciate a new odor. Specifically, we will direct experiments measuring (a) high-order dynamical structures associated with odor-response in the hawkmoth's antennal lobe and other synaptic centers including the lateral protocerebrum and mushroom bodies, and (b) the plasticity-induced shift in these structures following a conditioning paradigm. These experiments will facilitate development of both computational and theoretical models of neuronal networks. Specifically, we will develop (c) a large-scale spiking network model of the hawkmoth olfactory system which will be benchmarked using the experiments mentioned above, and (d) a theoretical framework capable of analyzing the rich dynamics found in these networks.
An abundance of recent experiments indicate that insects as well as other animals such as mammals, primates and humans, exhibit brain states that are incredibly rich, some directly induced by stimuli and some born from learning processes, all possessing dynamic properties on a variety of scales. The intricacies of these dynamic regimes are still a mystery. We currently do not know what these brain states are capable of, nor how they are used to drive decision making or learning. The hawkmoth -- "Manduca sexta" -- has a brain which is considerably simpler than a human's, but nevertheless has an olfactory system not too dissimilar from our own. By investigating the link between neuronal network dynamics, behavior and learning within this animal, we will draw conclusions relevant to some of our basic cognitive functions.
