Dummies versus air puffs: efficient stimulus delivery for low-volatile odors.
Aiming to unravel how animals perceive odors, a variety of neurophysiological techniques are used today. For olfactory stimulation, odors are commonly incorporated into a constant airstream that carries odor molecules to the receptor organ (air-delivered stimulation). Such odor delivery works well for odors of high volatility (naturally effective over long distances) but less or not at all for low-volatile odors (usually only received at short range). We developed a new odor stimulation technique especially suited for low-volatile odors and compared it with conventional air-delivered stimulation using 2 neurophysiological approaches. Odor-loaded dummies were moved into close vicinity of the receptor organs on the antenna of the Florida carpenter ant Camponotus floridanus (dummy-delivered stimulation). Neuronal activity was monitored either at receptor neuron level using electroantennography or in the first olfactory neuropile, the antennal lobes, using calcium imaging. We tested 3 odors of different volatility: C. floridanus' highly volatile alarm pheromone undecane, its low-volatile trail pheromone nerolic acid, and an even less volatile, behaviorally active C23 alkene, cis-9-tricosene. For low-volatile odors, dummy-delivered stimulation was particularly efficient. We conclude that dummy-delivered stimulation is advantageous compared to the commonly used air-delivered stimulation when studying an animal's detection and processing of low-volatile odors.
Brandstaetter
Andreas Simon
AS
Department of Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Biozentrum, Am Hubland, D-97074 Würzburg, Germany. brandstaetter@biozentrum.uni-wuerzburg.de
Rössler
Wolfgang
W
Kleineidam
Christoph Johannes
CJ
D000388:Air; D000473:Alkanes / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D001000:Ants / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D008348:Manikins; D009474:Neurons / Q000502:physiology; D009812:Odorants; D018035:Receptors, Odorant / Q000502:physiology; D012903:Smell / Q000502:physiology; D013268:Stimulation, Chemical; D014835:Volatilization
D000473:Alkanes; D018035:Receptors, Odorant; C022884:undecane; D002118:Calcium