Kevin Daly, Ph.D.
Animals, from simple insects to complex mammals like humans, depend upon olfaction to locate and assess a variety of resources such as mates, food and danger. They are capable of tracking odor plumes and trails across remarkable distances. Many insects, such as moths, track odor plumes by tacking back and forth through plumes. Furthermore, as they tack, the wing beat itself causes fluxes in air flow which temporally structures odor exposure. These active odor sampling behaviors are similar to mammals which also tack back and forth across odor trails and periodically sample by sniffing. Thus the timing with which odors contact the olfactory sensory array (the antenna in insects and the olfactory epithelium in mammals) affects how they are encoded by primary olfactory networks in the brain; this in turn affects odor perception. Finally, several lines of evidence establish that these active sampling behaviors, not only affect processing and perception but they are necessary for odors perception to occur. Recently, we showed that there are neural circuits that connect motor centers creating active sampling behaviors directly to the primary
olfactory processing center, the antennal lobe (Figure 1). We have shown that the antennal lobe is only capable of properly encoding odor stimuli when this motor-to-sensory circuit is intact. Furthermore, our intracellular recording of the two neurons making up this circuit demonstrate that they become active when the flight sensory motor system is activated (Figure 2). Furthermore,
disruption of this circuits ability to affect the antennal lobe disrupts the animals ability to properly perceive these odors (Figure 3). These results suggest that motor centers play a role in enhancing the fidelity with which the olfactory system encodes the timing of odors, yet little is known about the mechanisms underlying the integration of information between these two areas of the nervous system.
Currently my laboratory has several projects that leverage neuroanatomical, neurophysiological molecular genetic and behavioral approaches to determine the mechanisms by which input from the flight motor center of insects optimize the function of both the olfactory and auditory processing centers. This multidisciplinary approach will address my central hypothesis that identified neurons from the flight motor center provide direct input about wing beating behavior to the olfactory and auditory processing centers enhancing sensory function during flight and other wing behaviors. These projects involve a team of experts here at West Virginia University and Case Western Reserve University. This innovative approach promises to elucidate how and why a motor system modulates sensory function within the context of the active sampling behaviors that they produce. Discoveries made in this project will provide new insights into: 1) universal principles of active sampling and the temporal constraints that these behaviors place on olfactory processing; 2) the architecture and function of circuits that coordinate active sampling behaviors; 3) the functional consequences of disrupting these circuits on sensory network function and behavioral performance.
If you are a prospective student interested in conducting research in this field of study please contact me.Google Scholar