Mechanisms for mixture suppression in olfactory receptors of the spiny lobster

Ache, Barry W.; Gleeson, Richard A.; Thompson, Holly

doi:10.1093/chemse/13.3.425

Cited by 33 publications

(21 citation statements)

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“…Competitive inhibition at the peripheral level is one suppression mechanism (Gleeson and Ache, 1985;Cagan, 1986;Bruch and Rulli, 1988;Ache et al, 1988). Under this scenario, a binary mixture of TTX and arginine would compete for a single receptor subtype resulting in a loss of, or reduction in, neuronal stimulation relative to TTX alone.…”

Section: Discussionmentioning

confidence: 99%

The scent of danger: arginine as an olfactory cue of reduced predation risk

Ferrer

Zimmer

2007

Journal of Experimental Biology

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SUMMARY Animal perception of chemosensory cues is a function of ecological context. Larvae of the California newt (Taricha torosa), for example, exhibit predator-avoidance behavior in response to a chemical from cannibalistic adults. The poison tetrodotoxin (TTX), well known as an adult chemical defense, stimulates larval escape to refuges. Although they are cannibals,adult newts feed preferentially on worms (Eisenia rosea) over conspecific young. Hence, larval avoidance reactions to TTX are suppressed in the presence of odor from these alternative prey. The free amino acid,arginine, is abundant in fluids emitted by injured worms. Here, we demonstrate that arginine is a natural suppressant of TTX-stimulated larval escape behavior. Compared to a tapwater control, larvae initiated vigorous swimming in response to 10–7 mol l–1 TTX. This excitatory response was eliminated when larval nasal cavities were blocked with an inert gel, but not when gel was placed on the forehead (control). In additional trials, a binary mixture of arginine and 10–7 mol l–1 TTX failed to induce larval swimming. The inhibitory effect of arginine was, however, dose dependent. An arginine concentration as low as 0.3-times that of TTX was significantly suppressant. Further analysis showed that suppression by arginine of TTX-stimulated behavior was eliminated by altering the positively-charged guanidinium moiety, but not by modifying the carbon chain, carboxyl group, or amine group. These results are best explained by a mechanism of competitive inhibition between arginine and TTX for common, olfactory receptor binding sites. Although arginine alone has no impact on larval behavior, it nevertheless signals active adult predation on alternative prey, and hence, reduced cannibalism risk.

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Section: Discussionmentioning

confidence: 99%

The scent of danger: arginine as an olfactory cue of reduced predation risk

Ferrer

Zimmer

2007

Journal of Experimental Biology

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“…It is possible that mixture interactions occur between odorants not tested in this study. Indeed, interactions have been observed between carboxylic acids and amino acids in zebrafish (Fuss and Korsching, 2001) and in OSNs of other species (Ache et al, 1988;Laing et al, 1989;Ache and Zhainazarov, 1995;Kang and Caprio, 1997;Cromarty and Derby, 1998;Spehr et al, 2002). The occurrence of mixture interactions therefore may depend on the odor and species.…”

Section: Discussionmentioning

confidence: 99%

“…In OSNs, mixture interactions have been observed in vertebrates and invertebrates and may be mediated by competitive inhibition or synergistic activation of odorant receptors or by cross-talking signal transduction pathways (Ache et al, 1988;Laing et al, 1989;Ache and Zhainazarov, 1995;Kang and Caprio, 1997;Cromarty and Derby, 1998;Spehr et al, 2002). Mixture interactions also have been observed in the OB (Kang and Caprio, 1995;Giraudet et al, 2002;Wilson, 2003); however, the origin of the interactions has remained unknown.…”

Section: Introductionmentioning

confidence: 99%

Processing of Odor Mixtures in the Zebrafish Olfactory Bulb

Tabor¹,

Yaksi²,

Weislogel³

et al. 2004

J. Neurosci.

129

127

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Components of odor mixtures often are not perceived individually, suggesting that neural representations of mixtures are not simple combinations of the representations of the components. We studied odor responses to binary mixtures of amino acids and food extracts at different processing stages in the olfactory bulb (OB) of zebrafish. Odor-evoked input to the OB was measured by imaging Ca 2ϩ signals in afferents to olfactory glomeruli. Activity patterns evoked by mixtures were predictable within narrow limits from the component patterns, indicating that mixture interactions in the peripheral olfactory system are weak. OB output neurons, the mitral cells (MCs), were recorded extra-and intracellularly and responded to odors with stimulus-dependent temporal firing rate modulations. Responses to mixtures of amino acids often were dominated by one of the component responses. Responses to mixtures of food extracts, in contrast, were more distinct from both component responses. These results show that mixture interactions can result from processing in the OB. Moreover, our data indicate that mixture interactions in the OB become more pronounced with increasing overlap of input activity patterns evoked by the components. Emerging from these results are rules of mixture interactions that may explain behavioral data and provide a basis for understanding the processing of natural odor stimuli in the OB.

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“…Chemical stimuli were injected into this flow by activation of a pneumatic valve. Activation of the valve presented to the filament a stimulus with little dilution and a fast rise time that remained constant for over 5 s as determined by resistance measurements using distilled water as background flow and a NaCI solution as the injected stimulus (Ache et al 1988). The interval between stimulations was at least two rain.…”

Section: Antennular Preparation and Electrophysiological Recordingsmentioning

confidence: 99%

Responses of olfactory receptor neurons in the spiny lobster to binary mixtures are predictable using a noncompetitive model that incorporates excitatory and inhibitory transduction pathways

1996

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Coding of binary mixtures by a population of olfactory receptor neurons in the spiny lobster (Panulirus argus) was examined. Extracellular single-unit responses of 50 neurons to seven compounds and their binary mixtures were recorded. The ability of a noncompetitive model with correction for binding inhibition to predict responses to mixtures based on responses to their components was compared with the predictive abilities of other models. This model assumes that different compounds activate different transduction processes in the same neuron leading to excitation or inhibition, and it includes a term quantifying the degree to which binding of an odorant to its receptor sites is inhibited by other compounds. The model accurately predicted the absolute response magnitude of the population of neurons for 13 of 15 mixtures assessed, which is superior to the predictive power of any of the other models. The model also accurately predicted the across neuron patterns generated by the binary mixtures, as evaluated by multidimensional scaling analysis. The results suggest that there is no emergence of unique qualities for binary mixtures relative to components of these mixtures.

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Mechanisms for mixture suppression in olfactory receptors of the spiny lobster

Cited by 33 publications

References 0 publications

The scent of danger: arginine as an olfactory cue of reduced predation risk

The scent of danger: arginine as an olfactory cue of reduced predation risk

Processing of Odor Mixtures in the Zebrafish Olfactory Bulb

Responses of olfactory receptor neurons in the spiny lobster to binary mixtures are predictable using a noncompetitive model that incorporates excitatory and inhibitory transduction pathways

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