Kevin Daly, PhD
PO Box 6057
Morgantown, WV 26506
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.
- Chapman, P. D., Burkland, R., Bradley, S. P., Houot, B., Bullman, V., Dacks, A. M., & Daly, K. C. (2018). Flight motor networks modulate primary olfactory processing in the moth Manduca sexta. Proc Natl Acad Sci U S A. (2018) doi:10.1073/pnas.1722379115
- Chapman, P.D., Bradley, S.P., Haught, E.J., Riggs, K.E., Haffar, M.M., Daly, K.C., and Dacks, A.M. Co-option of a motor-to-sensory histaminergic circuit correlates with insect flight biomechanics. Proc. R. Soc. B Biol. Sci. 284, (2017). doi: 10.1098/rspb.2017.0339.
- Klinner, C., König, C., Missbach, C., Werckenthin, A., Daly, K.C., Bisch-Knaden, S., Stengl, M., Hansson, B.S. Große-Wilde, E. Functional olfactory sensory neurons housed in olfactory sensilla on the ovipositor of the hawkmoth Manduca sexta. Frontiers in Ecology and Evolution 4, (2016). doi: 10.3389/fevo.2016.00130.
- Bradley, S.P., Chapman, P.D., Lizbinski, K.M., Daly, K.C., Dacks, A.M. A Flight Sensory-Motor to Olfactory Processing Circuit in the Moth Manduca sexta. Frontiers in Neural Circuits. (2016) 10:5. doi:10.3389/fncir.2016.00005.
- Daly, K.C., Bradley, S., Chapman, P.D., Staudacher, E.M., Tiede, R., Schachtner, J. Space Takes Time: Concentration Dependent Output Codes from Primary Olfactory Networks Rapidly Provide Additional Information at Defined Discrimination Thresholds. Frontiers in Cellular Neuroscience (2015)9:515. doi:10.3389/fncel.2015.00515.
- Houot B, Burkland R, Tripathy S, and Daly KC. Antennal lobe representations are optimized when olfactory stimuli are periodically structured to simulate natural wing beat effects. Frontiers in Cellular Neuroscience (2014) 8: 159.
- Daly KC, Kalwar F, Hatfield M, Staudacher E, Bradley SP. Odor Detection in Manduca sexta Is Optimized when Odor Stimuli Are Pulsed at a Frequency Matching the Wing Beat during Flight. PLoS One (2013 Nov) 8(11):e81863.
- Gage SL, Daly KC, Nighorn A. Nitric oxide affects short-term olfactory memory in the antennal lobe of Manduca sexta. J Exp Biol (2013 Sep) 1;216(Pt 17): 3294-300.
- Daly KC, Galán RF, Peters OJ, Staudacher EM. Detailed Characterization of Local Field Potential Oscillations and Their Relationship to Spike Timing in the Antennal Lobe of the Moth Manduca sexta. Front Neuroeng (2011) 4:12. doi: 10.3389/fneng.2011.00012.
- Farris SM, Pettrey C,Daly KC. A subpopulation of mushroom body intrinsic neurons is generated by protocerebral neuroblasts in the tobacco hornworm moth, Manduca sexta (Sphingidae, Lepidoptera). Arthropod Struct Dev. (2011 Sep) 40(5):395-408. doi: 10.1016/j.asd.2010.10.004.
- Tripathy SJ, Peters OJ, Staudacher EM, Kalwar FR, Hatfield MN, Daly KC. Odors Pulsed at Wing Beat Frequencies are Tracked by Primary Olfactory Networks and Enhance Odor Detection. Front Cell Neurosci (2010), 16;4:1