Dynamic Properties of Antennal Responses to Pheromone in Two Moth Species

Abstract

. Dynamic properties of pheromone plumes are behaviorally important in some moths for inducing upwind flight, but little is known about the time-dependent properties of odor transduction or the mechanisms that limit receptor dynamic sensitivity. We stimulated male antennae of two moth species, Cadra cautella and Spodoptera exigua, with pheromone plumes in a wind tunnel while recording electroantennograms (EAG) and concentration of a surrogate plume (propylene, which mimics a pheromone plume) using a photoionization detector (PID). Turbulent plumes were produced by mechanical baffles, creating broad frequency range dynamic concentration changes at the antennae. Frequency response functions and coherence functions between PID and EAG signals were used to measure the dynamic responses of the two species to pheromone blends and individual components. A single time constant filter fitted the responses of both species, but S. exigua was about three times faster than C. cautella. Responses to individual pheromone components were significantly different in S. exigua but not in C. cautella. We also fitted the data with a simple blockstructured nonlinear cascade. This supported the simple filter model but also suggested that the response saturates at an early stage of chemotransduction.

High-speed odor transduction and pulse tracking by insect olfactory receptor neurons

“…provides a tool to measure the ORNs' temporal resolution (15,16). We identified the antennae's temporal resolution as the maximum stimulus frequencies at which the coherence between the EAG response and the TiCl 4 smoke signal was significant at the 5 sigma level (Fig.…”

“…Olfactory transduction speed has never been measured directly, and estimates range from 10 to 30 ms (8)(9)(10)(11). Previous studies suggest that the maximum pulse tracking frequency of ORNs is species specific and ranges from 5 to 50 Hz (12)(13)(14)(15)(16)(17)(18)(19). However, these numbers do not match the high temporal resolution observed in behavioral studies (2)(3)(4)(5)(6)(7).…”

A model of visual–olfactory integration for odour localisation in free-flying fruit flies

“…Thus the model fly's olfactory input signal can be taken as a scalar value. Olfactory receptor neurons are known to have low-pass (Justus et al, 2004;Schuckel et al, 2008) as well as high-pass (i.e. adaptation) characteristics (Störtkuhl et al, 1999).…”

The spatial and temporal patterns of odors sampled by lobsters and crabs in a turbulent plume

“…The bursts of firing by antennule olfactory receptor neurons of P. argus adapt selectively to odor pulses at frequencies of 0.5-0.1Hz (Marschall and Ache, 1989). Moth antennal receptor cells can resolve odor pulses at 2-5Hz (Rumbo and Kaissling, 1989) but show flicker fusion at 10Hz (Justus and Cardé, 2002), while electroantennograms show that odor pulses of 5-33Hz can be resolved, depending on the type of odorant and species of moth (Bau et al, 2002;Bau et al, 2005;Justus et al, 2005;Tripathy et al, 2010). The output of the moth olfactory antennal lobe, where local field potentials can track pulses up to 30Hz (Tripathy et al, 2010), also varies with the frequency of signal input (Vickers et al, 2001).…”