2009 Abstracts - Association for Chemoreception Sciences

#P86 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyAntennular Waving in Spiny Lobsters is Enhanced byOdorants: A 3D Kinematic AnalysisPeter C. Daniel, Calvin CarterHofstra University Hempstead, NY, USAA major goal of chemosensory guidance research is to elucidatehow animals extract information from the complex spatial andtemporal structure of odorant plumes. Studies using lobsters asmodel organisms have examined orientation and locomotion ofthe whole animal as it encounters odorant plumes, as well as theflicking behavior of the antennules, the olfactory organ.Antennules can also move independently of general bodymovements by adjusting the joints of segments of the antennulesmore proximal to the body than the lateral and medial flagella thatcontain chemosensilla. These movements, referred to asantennular waving, have been observed anecdotally to increase inthe presence of chemical stimuli. This hypothesis was tested bystereoscopic filming of antennular waving of 10 spiny lobsters,Panulirus argus, towards control seawater and squid extract. 3Dkinematic analysis software was used to measure the second bysecond coordinates of antennules and the body over 60 secfollowing stimulus introduction. Antennule coordinates werecorrected for body position. Antennular waving increased about50% upon introduction of squid extract relative to controlresponses. However antennular waving and body movement arepositively correlated independent of stimulus type. Left and rightantennular waving averaged over 60 sec were strongly correlated.However second by second velocities of the two antennules werenot correlated. Thus left and right antennule movements, whilenot synchronized, are both tightly coupled to body movement.We also report preliminary results of ablation studies designed todetermine contributions of nonolfactory and olfactory inputs toantennular waving. These results suggest that antennular wavingcontributes to increased spatial sampling in the presence ofodorants.#P87 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyThe effect of sniffing frequency on odor behaviorKeiichi TonosakiMeikai Univ Sakatoshi, JapanMany animals, such as horses, sheep, dogs, cats, rats and micecommonly exhibit the sniffing behavior when they are searchingthe foods or the odors. It is believed that the sniffing is one of theimportant behaviors in their life. It is possible that change insniffing frequency and (or) strengthen, then the odor samplingbehavior and the olfactory receptor cell responses may be changedand alter higher order coding. Standard respiration rate in rats is1-2 Hz but sniffing varies between 4-12 Hz. Olfactory receptorcells are elicited the responses by the absorption of the chemicalsubstances. We used continuously or intermittent (mimicked thesniffing respiration pattern) application of odor stimulationmethods, and have investigated that changes in sniff frequencycould be changed the level of odor behavior or not, and howsniffing alters odor responses during the different sniffingbehavior.#P88 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyDetailed Analysis of the Effects of Periodic Input on BehavioralMeasures of Odor Detection in the Moth Manduca sextaMandy N. Hatfield , Faizan R. Kalwar , Kevin C. DalyWest Virginia University Morgantown, WV, USAIn mammals, sniffing is an active odor sampling process.In moths, the wing beat oscillates airflow over the antennaeaffecting olfactory input, which may affect sensitivity. To test thishypothesis, we generated concentration response functions usingtrained Manduca sexta moths. Moths were conditioned toassociate a conditioning stimulus (odor; CS) with sucrose usingclassical conditioning. At 24 then 48 hours after conditioning,moths were tested with either a pulsed or continuous CS. Pulsetrains were 4 s long, 20 Hz (the approximate wing beatfrequency), with either a 10:40 ms (ON:OFF) or 40:10 ms dutycycle. Duration of continuous stimuli was normalized to theintegrated pulse duration. Stimuli were presented across a 5 logstepdilution series from low to high. Flow velocity was ~30 or~80 cm/s (speeds consistent with odor-guided flight). To controlfor extinction effects, 5 groups were tested with one dilution. Tocorrect for the total stimulus duration, one group received thecontinuous stimuli at 1/5 the concentration (replicating the 10:40duty cycle). We also statistically normalized responses to percentresponse/ms on-time. To control for stimulus-specific mechanicaleffects, responses to blanks were recorded for both stimuli andused for normalization of odor responses. Results of ANOVAindicated that the percentage of moths responding to the CSincreased significantly as a function of concentration. Importantly,pulsed stimuli significantly enhanced sensitivity to odor; this wastrue across all control groups. Results of these behavioralexperiments support the hypothesis that periodic stimuli increaseodor salience in this moth species.#P89 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyPeriodic Odor Stimulation Affects Antennal Input,Antennal Lobe Processing, and Behavioral Measures ofPerception in the Moth Manduca sextaKevin C. Daly 1 , Shreejoy Tripathy 2 , Erich M. Staudacher 1 ,Oakland J. Peters 1 , Mandy N. Hatfield 1 , Faizan R. Kalwar 11West Virginia University Morgantown, WV, USA, 2 CarnegieMellon University Pittsburgh, PA, USABiomechanical studies of the insect wing beat show that eachdown stroke increases air flow over the antennae. This couldaffect penetration of odor on the sensilla, thus, providing atemporally patterned antennal lobe (AL) input in a manner similarto mammalian sniffing. Does the antenna and AL respond to odorstimulation on a wing beat timescale (18-28Hz) and can this affectperceptual acuity? To address these questions, we varied stimulusfrequency and measured antennal responses in Manduca sextamoths, via electroantennograms (EAGs). Spectral analysis ofEAG responses indicated significant pulse tracking up to 30Hz.Responses to blanks were significant up to 25Hz, but weresignificantly smaller than pulsed odor. Using in vivo multielectrode methods, we show that both AL local field potential andunitary responses tightly track periodic stimuli at wing beatfrequencies. Local field potentials tracked stimuli beyond thewing beat frequency (up to 72Hz). Furthermore ~25% of54 | AChemS Abstracts 2009