The Experts below are selected from a list of 3267 Experts worldwide ranked by ideXlab platform
Thomas C Baker - One of the best experts on this subject based on the ideXlab platform.
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reduction in host finding behaviour in fungus infected mosquitoes is correlated with reduction in Olfactory Receptor Neuron responsiveness
Malaria Journal, 2011Co-Authors: Justin George, Michael J Domingue, Simon Blanford, Matthew B Thomas, Andrew F Read, Thomas C BakerAbstract:Chemical insecticides against mosquitoes are a major component of malaria control worldwide. Fungal entomopathogens formulated as biopesticides and applied as insecticide residual sprays could augment current control strategies and mitigate the evolution of resistance to chemical-based insecticides. Anopheles stephensi mosquitoes were exposed to Beauveria bassiana or Metarhizium acridum fungal spores and sub-lethal effects of exposure to fungal infection were studied, especially the potential for reductions in feeding and host location behaviours related to olfaction. Electrophysiological techniques, such as electroantennogram, electropalpogram and single sensillum recording techniques were then employed to investigate how fungal exposure affected the Olfactory responses in mosquitoes. Exposure to B. bassiana caused significant mortality and reduced the propensity of mosquitoes to respond and fly to a feeding stimulus. Exposure to M. acridum spores induced a similar decline in feeding propensity, albeit more slowly than B. bassiana exposure. Reduced host-seeking responses following fungal exposure corresponded to reduced Olfactory Neuron responsiveness in both antennal electroantennogram and maxillary palp electropalpogram recordings. Single cell recordings from Neurons on the palps confirmed that fungal-exposed behavioural non-responders exhibited significantly impaired responsiveness of Neurons tuned specifically to 1-octen-3-ol and to a lesser degree, to CO2. Fungal infection reduces the responsiveness of mosquitoes to host odour cues, both behaviourally and Neuronally. These pre-lethal effects are likely to synergize with fungal-induced mortality to further reduce the capacity of mosquito populations exposed to fungal biopesticides to transmit malaria.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the ‘‘univoltine Z-strain’’ European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F1 hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F1 hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spikeamplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain. 2009 Published by Elsevier Ltd.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the "univoltine Z-strain" European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F(1) hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F(1) hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spike-amplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain.
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altered Olfactory Receptor Neuron responsiveness is correlated with a shift in behavioral response in an evolved colony of the cabbage looper moth trichoplusia ni
Journal of Chemical Ecology, 2009Co-Authors: Michael J Domingue, Julie L. Todd, Kenneth F Haynes, Thomas C BakerAbstract:There is little understanding of how sex pheromone blends might change during speciation events. For the cabbage looper, Trichoplusia ni, there is a mutant laboratory strain that has exhibited characteristics of a shift to a new pheromone blend. Mutant females produce a blend that is significantly different from wild-type females in having a much higher proportion of a minor pheromone component and lower quantity of the major component. Males in this colony have changed over the years to become more broadly tuned and fly upwind equally well to both the wild-type and mutant female pheromone blends. They also exhibit reduced overall sensitivity to pheromone, flying upwind to either blend at a lower success rate than is typical when wild-type males respond to the wild-type blend. Using single-cell recordings, we examined the Olfactory Receptor Neurons (ORNs) of males from evolved and wild-type colonies for evidence of changes in response characteristics that might explain the above-described behavioral evolution. We found that in evolved-colony males the ORNs tuned to the major sex pheromone component exhibited a somewhat lower responsiveness to that compound than the ORNs of wild-type males. In addition, the minor pheromone component, emitted at excessively high rates by mutant females, elicited a drastically reduced ORN responsiveness in evolved-colony males compared to wild-type males. This alteration in ORN responsiveness may be responsible for allowing evolved males to tolerate the excessive amounts of the minor pheromone component in the mutant female blend, which would normally antagonize the upwind flight of unevolved males. Thus, peripheral Olfactory alterations have occurred in T. ni males that are correlated with the evolution of the more broadly tuned, but less sensitive, behavioral response profile.
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Olfactory Neuron responsiveness and pheromone blend preference in hybrids between ostrinia furnacalis and ostrinia nubilalis lepidoptera crambidae
Journal of Insect Physiology, 2008Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:The Olfactory Receptor Neuron (ORN) and behavioral responses of hybrids between the Asian corn borer (ACB), Ostrinia furnacalis, and the E-strain European corn borer (ECB(E)), Ostrinia nubilalis were examined and compared to the parental populations. In hybrids and both parents, the large-spike-size ORN was capable of responding to all four pheromone components of ACB and ECB, despite differences in which compounds elicited the greatest spike frequency in each population. There was a small-spiking ORN more narrowly tuned to the minor pheromone components in both ACB and ECB(E). In hybrids the homologous small-spiking ORN was tuned primarily to the ECB(E) minor pheromone component, with some responsiveness to the ACB minor component. Both species and all the hybrids had an intermediate spike-size ORN tuned primarily to their common behavioral antagonist. Dominance of responsiveness to the ECB(E) versus the ACB minor pheromone component on the small-spiking ORN may explain the greater tendency of hybrids to fly upwind to the ECB(E) pheromone blend than the ACB blend. This finding points toward a distinct evolutionary role for this ORN in allowing a pheromone shift.
Michael J Domingue - One of the best experts on this subject based on the ideXlab platform.
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reduction in host finding behaviour in fungus infected mosquitoes is correlated with reduction in Olfactory Receptor Neuron responsiveness
Malaria Journal, 2011Co-Authors: Justin George, Michael J Domingue, Simon Blanford, Matthew B Thomas, Andrew F Read, Thomas C BakerAbstract:Chemical insecticides against mosquitoes are a major component of malaria control worldwide. Fungal entomopathogens formulated as biopesticides and applied as insecticide residual sprays could augment current control strategies and mitigate the evolution of resistance to chemical-based insecticides. Anopheles stephensi mosquitoes were exposed to Beauveria bassiana or Metarhizium acridum fungal spores and sub-lethal effects of exposure to fungal infection were studied, especially the potential for reductions in feeding and host location behaviours related to olfaction. Electrophysiological techniques, such as electroantennogram, electropalpogram and single sensillum recording techniques were then employed to investigate how fungal exposure affected the Olfactory responses in mosquitoes. Exposure to B. bassiana caused significant mortality and reduced the propensity of mosquitoes to respond and fly to a feeding stimulus. Exposure to M. acridum spores induced a similar decline in feeding propensity, albeit more slowly than B. bassiana exposure. Reduced host-seeking responses following fungal exposure corresponded to reduced Olfactory Neuron responsiveness in both antennal electroantennogram and maxillary palp electropalpogram recordings. Single cell recordings from Neurons on the palps confirmed that fungal-exposed behavioural non-responders exhibited significantly impaired responsiveness of Neurons tuned specifically to 1-octen-3-ol and to a lesser degree, to CO2. Fungal infection reduces the responsiveness of mosquitoes to host odour cues, both behaviourally and Neuronally. These pre-lethal effects are likely to synergize with fungal-induced mortality to further reduce the capacity of mosquito populations exposed to fungal biopesticides to transmit malaria.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the ‘‘univoltine Z-strain’’ European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F1 hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F1 hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spikeamplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain. 2009 Published by Elsevier Ltd.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the "univoltine Z-strain" European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F(1) hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F(1) hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spike-amplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain.
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altered Olfactory Receptor Neuron responsiveness is correlated with a shift in behavioral response in an evolved colony of the cabbage looper moth trichoplusia ni
Journal of Chemical Ecology, 2009Co-Authors: Michael J Domingue, Julie L. Todd, Kenneth F Haynes, Thomas C BakerAbstract:There is little understanding of how sex pheromone blends might change during speciation events. For the cabbage looper, Trichoplusia ni, there is a mutant laboratory strain that has exhibited characteristics of a shift to a new pheromone blend. Mutant females produce a blend that is significantly different from wild-type females in having a much higher proportion of a minor pheromone component and lower quantity of the major component. Males in this colony have changed over the years to become more broadly tuned and fly upwind equally well to both the wild-type and mutant female pheromone blends. They also exhibit reduced overall sensitivity to pheromone, flying upwind to either blend at a lower success rate than is typical when wild-type males respond to the wild-type blend. Using single-cell recordings, we examined the Olfactory Receptor Neurons (ORNs) of males from evolved and wild-type colonies for evidence of changes in response characteristics that might explain the above-described behavioral evolution. We found that in evolved-colony males the ORNs tuned to the major sex pheromone component exhibited a somewhat lower responsiveness to that compound than the ORNs of wild-type males. In addition, the minor pheromone component, emitted at excessively high rates by mutant females, elicited a drastically reduced ORN responsiveness in evolved-colony males compared to wild-type males. This alteration in ORN responsiveness may be responsible for allowing evolved males to tolerate the excessive amounts of the minor pheromone component in the mutant female blend, which would normally antagonize the upwind flight of unevolved males. Thus, peripheral Olfactory alterations have occurred in T. ni males that are correlated with the evolution of the more broadly tuned, but less sensitive, behavioral response profile.
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Olfactory Neuron responsiveness and pheromone blend preference in hybrids between ostrinia furnacalis and ostrinia nubilalis lepidoptera crambidae
Journal of Insect Physiology, 2008Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:The Olfactory Receptor Neuron (ORN) and behavioral responses of hybrids between the Asian corn borer (ACB), Ostrinia furnacalis, and the E-strain European corn borer (ECB(E)), Ostrinia nubilalis were examined and compared to the parental populations. In hybrids and both parents, the large-spike-size ORN was capable of responding to all four pheromone components of ACB and ECB, despite differences in which compounds elicited the greatest spike frequency in each population. There was a small-spiking ORN more narrowly tuned to the minor pheromone components in both ACB and ECB(E). In hybrids the homologous small-spiking ORN was tuned primarily to the ECB(E) minor pheromone component, with some responsiveness to the ACB minor component. Both species and all the hybrids had an intermediate spike-size ORN tuned primarily to their common behavioral antagonist. Dominance of responsiveness to the ECB(E) versus the ACB minor pheromone component on the small-spiking ORN may explain the greater tendency of hybrids to fly upwind to the ECB(E) pheromone blend than the ACB blend. This finding points toward a distinct evolutionary role for this ORN in allowing a pheromone shift.
Wendell L. Roelofs - One of the best experts on this subject based on the ideXlab platform.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the ‘‘univoltine Z-strain’’ European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F1 hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F1 hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spikeamplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain. 2009 Published by Elsevier Ltd.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the "univoltine Z-strain" European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F(1) hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F(1) hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spike-amplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain.
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Olfactory Neuron responsiveness and pheromone blend preference in hybrids between ostrinia furnacalis and ostrinia nubilalis lepidoptera crambidae
Journal of Insect Physiology, 2008Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:The Olfactory Receptor Neuron (ORN) and behavioral responses of hybrids between the Asian corn borer (ACB), Ostrinia furnacalis, and the E-strain European corn borer (ECB(E)), Ostrinia nubilalis were examined and compared to the parental populations. In hybrids and both parents, the large-spike-size ORN was capable of responding to all four pheromone components of ACB and ECB, despite differences in which compounds elicited the greatest spike frequency in each population. There was a small-spiking ORN more narrowly tuned to the minor pheromone components in both ACB and ECB(E). In hybrids the homologous small-spiking ORN was tuned primarily to the ECB(E) minor pheromone component, with some responsiveness to the ACB minor component. Both species and all the hybrids had an intermediate spike-size ORN tuned primarily to their common behavioral antagonist. Dominance of responsiveness to the ECB(E) versus the ACB minor pheromone component on the small-spiking ORN may explain the greater tendency of hybrids to fly upwind to the ECB(E) pheromone blend than the ACB blend. This finding points toward a distinct evolutionary role for this ORN in allowing a pheromone shift.
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altered Olfactory Receptor Neuron responsiveness in rare ostrinia nubilalis males attracted to the o furnacalis pheromone blend
Journal of Insect Physiology, 2007Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:Abstract Three percent of E-strain Ostrinia nubilalis males fly upwind in response to the Ostrinia furnacalis pheromone blend [a 40:60 ratio of ( E )-12-tetradecenyl acetate to ( Z )-12-tetradecenyl acetate (E12-14:OAc to Z12-14:OAc)], in addition to their own pheromone blend [a 99:1 ratio of ( E )-11-tetradecenyl acetate to ( Z )-11-tetradecenyl acetate) (E11-14:OAc to Z11-14:OAc)]. We assessed the Olfactory Receptor Neuron (ORN) responses of these behaviorally “rare” males versus those of normal males. For the three ORNs housed within each sensillum, we tested responsiveness to Z12-14:OAc, E12-14:OAc, Z11-14:OAc, E11-14:OAc, and the behavioral antagonist ( Z )-9-tetradecenyl acetate (Z9-14:OAc). Z11-14:OAc, E11-14:OAc, and Z9-14:OAc stimulated ORNs exhibiting distinct small, large, and medium spike sizes, respectively. For rare and normal males, both Z12-14:OAc and E12-14:OAc usually elicited responses from the largest-spiking ORN. In many ORNs of normal males, Z12-14:OAc or E12-14:OAc stimulated the smaller-spiking ORN that is responsive to Z11-14:OAc. In rare males, detectable ORN responses from the smaller-spiking ORN in response to Z12- and E12-14:OAc were virtually non-existent. These differences in ORN tuning in rare males will tend to create an ORN firing ratio between the large- and small-spiking ORNs in response to the O. furnacalis blend that is similar to that elicited by the O. nubilalis blend.
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support for z 11 hexadecanal as a pheromone antagonist in ostrinia nubilalis flight tunnel and single sensillum studies with a new york population
Journal of Chemical Ecology, 2007Co-Authors: Charles E Linn, Callie J Musto, Michael J Domingue, Thomas C Baker, Wendell L. RoelofsAbstract:The flight-tunnel response of male Z-strain European corn borer moths (ECB), Ostrinia nubilalis, from a population in New York State (USA), was significantly antagonized by addition of 1% (Z)-11-hexadecanal (Z11-16:Ald) to their sex pheromone (a 97:3 mix of (Z)- and (E)-11-tetradecenyl acetate [Z/E11-14:OAc]). The level of antagonism was equivalent to that observed for the previously identified ECB antagonist, (Z)-9-tetradecenyl acetate (Z9-14:OAc), and supports a recent report showing that Z11-16:Ald, a minor pheromone component of the Noctuid moth, Sesamia nonagrioides, caused antagonism of ECB pheromone communication in sympatric populations in the Iberian Peninsula. Single-sensillum recordings from ECB antennae, which included cross-adaptation experiments, showed that the same Olfactory Receptor Neuron processing Z9-14:OAc inputs was responsible for detecting Z11-16:Ald, and that this Neuron was not responsive to two other aldehydes, (Z)-9-tetradecanal (Z9-14:Ald) and (Z)-9-hexadecanal (Z9-16:Ald), found in other moth sex pheromones. Our results show that the antagonism is not confined to one geographic region, is specific for Z11-16:Ald, and that antagonist pathways might have the potential for processing a number of structurally similar compounds.
Charles E Linn - One of the best experts on this subject based on the ideXlab platform.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the ‘‘univoltine Z-strain’’ European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F1 hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F1 hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spikeamplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain. 2009 Published by Elsevier Ltd.
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homology of Olfactory Receptor Neuron response characteristics inferred from hybrids between asian and european corn borer moths lepidoptera crambidae
Journal of Insect Physiology, 2010Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the "univoltine Z-strain" European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F(1) hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F(1) hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spike-amplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain.
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Olfactory Neuron responsiveness and pheromone blend preference in hybrids between ostrinia furnacalis and ostrinia nubilalis lepidoptera crambidae
Journal of Insect Physiology, 2008Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:The Olfactory Receptor Neuron (ORN) and behavioral responses of hybrids between the Asian corn borer (ACB), Ostrinia furnacalis, and the E-strain European corn borer (ECB(E)), Ostrinia nubilalis were examined and compared to the parental populations. In hybrids and both parents, the large-spike-size ORN was capable of responding to all four pheromone components of ACB and ECB, despite differences in which compounds elicited the greatest spike frequency in each population. There was a small-spiking ORN more narrowly tuned to the minor pheromone components in both ACB and ECB(E). In hybrids the homologous small-spiking ORN was tuned primarily to the ECB(E) minor pheromone component, with some responsiveness to the ACB minor component. Both species and all the hybrids had an intermediate spike-size ORN tuned primarily to their common behavioral antagonist. Dominance of responsiveness to the ECB(E) versus the ACB minor pheromone component on the small-spiking ORN may explain the greater tendency of hybrids to fly upwind to the ECB(E) pheromone blend than the ACB blend. This finding points toward a distinct evolutionary role for this ORN in allowing a pheromone shift.
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altered Olfactory Receptor Neuron responsiveness in rare ostrinia nubilalis males attracted to the o furnacalis pheromone blend
Journal of Insect Physiology, 2007Co-Authors: Michael J Domingue, Wendell L. Roelofs, Charles E Linn, Callie J Musto, Thomas C BakerAbstract:Abstract Three percent of E-strain Ostrinia nubilalis males fly upwind in response to the Ostrinia furnacalis pheromone blend [a 40:60 ratio of ( E )-12-tetradecenyl acetate to ( Z )-12-tetradecenyl acetate (E12-14:OAc to Z12-14:OAc)], in addition to their own pheromone blend [a 99:1 ratio of ( E )-11-tetradecenyl acetate to ( Z )-11-tetradecenyl acetate) (E11-14:OAc to Z11-14:OAc)]. We assessed the Olfactory Receptor Neuron (ORN) responses of these behaviorally “rare” males versus those of normal males. For the three ORNs housed within each sensillum, we tested responsiveness to Z12-14:OAc, E12-14:OAc, Z11-14:OAc, E11-14:OAc, and the behavioral antagonist ( Z )-9-tetradecenyl acetate (Z9-14:OAc). Z11-14:OAc, E11-14:OAc, and Z9-14:OAc stimulated ORNs exhibiting distinct small, large, and medium spike sizes, respectively. For rare and normal males, both Z12-14:OAc and E12-14:OAc usually elicited responses from the largest-spiking ORN. In many ORNs of normal males, Z12-14:OAc or E12-14:OAc stimulated the smaller-spiking ORN that is responsive to Z11-14:OAc. In rare males, detectable ORN responses from the smaller-spiking ORN in response to Z12- and E12-14:OAc were virtually non-existent. These differences in ORN tuning in rare males will tend to create an ORN firing ratio between the large- and small-spiking ORNs in response to the O. furnacalis blend that is similar to that elicited by the O. nubilalis blend.
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support for z 11 hexadecanal as a pheromone antagonist in ostrinia nubilalis flight tunnel and single sensillum studies with a new york population
Journal of Chemical Ecology, 2007Co-Authors: Charles E Linn, Callie J Musto, Michael J Domingue, Thomas C Baker, Wendell L. RoelofsAbstract:The flight-tunnel response of male Z-strain European corn borer moths (ECB), Ostrinia nubilalis, from a population in New York State (USA), was significantly antagonized by addition of 1% (Z)-11-hexadecanal (Z11-16:Ald) to their sex pheromone (a 97:3 mix of (Z)- and (E)-11-tetradecenyl acetate [Z/E11-14:OAc]). The level of antagonism was equivalent to that observed for the previously identified ECB antagonist, (Z)-9-tetradecenyl acetate (Z9-14:OAc), and supports a recent report showing that Z11-16:Ald, a minor pheromone component of the Noctuid moth, Sesamia nonagrioides, caused antagonism of ECB pheromone communication in sympatric populations in the Iberian Peninsula. Single-sensillum recordings from ECB antennae, which included cross-adaptation experiments, showed that the same Olfactory Receptor Neuron processing Z9-14:OAc inputs was responsible for detecting Z11-16:Ald, and that this Neuron was not responsive to two other aldehydes, (Z)-9-tetradecanal (Z9-14:Ald) and (Z)-9-hexadecanal (Z9-16:Ald), found in other moth sex pheromones. Our results show that the antagonism is not confined to one geographic region, is specific for Z11-16:Ald, and that antagonist pathways might have the potential for processing a number of structurally similar compounds.
Jean-pierre Rospars - One of the best experts on this subject based on the ideXlab platform.
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Olfactory Receptor Neuron coding in the turbulent realm
BMC Neuroscience, 2013Co-Authors: Jeanbaptiste Masson, Jean-pierre Rospars, Christelle Monsempes, Philippe LucasAbstract:Insects are able to find their mates from the sparse pheromone patches transported by turbulent air streams. This source-finding ability is remarkable because the pheromone patches don’t point towards the source and because the temporal and concentration statistics encountered during the search are highly irregular. The knowledge of the coding dynamics at the single ORN level is presently incomplete and it seems mandatory to decipher these dynamics before further investigating the integration of the signal at higher levels of the Olfactory system. A Receptor that would attempt to infer the distance of a source from the detection dynamics of the pheromone patches would obviously benefit from the complete evolution of the pheromone concentration with time. Yet, it is possible to build a Bayesian model based on the known dynamics of the plume propagation [1] and to infer the distance from the temporal dynamics only. Hence, an interesting question is how much of the temporal dynamics of the patches can be encoded in the ORN signals? For example, the uncorrelated statistics of patch duration is sufficient for inferring the distance, yet including the correlations between the durations of detections and non-detections will greatly improve the decoding rate [2]. As a simplified framework, we investigated the dynamical Olfactory coding of ORNs of a moth, Agrotis ipsilon, stimulated by puffs of pheromone (cis-7-dodecenyl acetate) of variable duration delivered at constant concentration. The spiking responses of ORNs to single puffs varying over four decades of durations (1ms-10s) were recorded and decoded. In the absence of precise knowledge on the decoding mechanism inside the antennal lobe and in higher neural structures of the insect brain, 3 decoding schemes were utilized, based on logistic regression, support vector machine and signal dependent Poisson firing model designed to include bursting dynamics. With this protocol the relative selectivity of ORNs coding with the variation of puff duration and thus the relative information transfer could be analyzed. Then, in order to investigate the possible coding dependency of the currently detected pheromone patch on previous patch detections, double puffs coding were investigated, similarly over four decades of durations. The evolution of the ORN coding showed that the detection of previous puffs influenced the coding of the current puff and hence that instantaneous decoding could bring information on the previous puff duration and timing. Furthermore, we quantified the relative (conditional) sensitivity of the instantaneous coding with respect to the duration and spacing of the previous puff. Interestingly, we also show that the “random spiking” dynamics bears a non-negligible amount of information on the past patch dynamics detection. The coding and decoding procedures were then evaluated on signals mimicking the temporal dynamics of patches in a turbulent stream. We found that training based on one patch and two patches allowed efficient and reliable decoding of patch dynamics in turbulent air streams. Finally, we quantified the amount of information encoded by ORNs about the duration, timing, and most importantly waiting time between consecutive pheromone puffs.
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Dynamical modeling of the moth pheromone-sensitive Olfactory Receptor Neuron within its sensillar environment
PLoS ONE, 2011Co-Authors: Jean-pierre RosparsAbstract:In insects, Olfactory Receptor Neurons (ORNs), surrounded with auxiliary cells and protected by a cuticular wall, form small discrete sensory organs - the sensilla. The moth pheromone-sensitive sensillum is a well studied example of hair-like sensillum that is favorable to both experimental and modeling investigations. The model presented takes into account both the molecular processes of ORNs, i.e. the biochemical reactions and ionic currents giving rise to the Receptor potential, and the cellular organization and compartmentalization of the organ represented by an electrical circuit. The number of isopotential compartments needed to describe the long dendrite bearing pheromone Receptors was determined. The transduction parameters that must be modified when the number of compartments is increased were identified. This model reproduces the amplitude and time course of the experimentally recorded Receptor potential. A first complete version of the model was analyzed in response to pheromone pulses of various strengths. It provided a quantitative description of the spatial and temporal evolution of the pheromone-dependent conductances, currents and potentials along the outer dendrite and served to determine the contribution of the various steps in the cascade to its global sensitivity. A second simplified version of the model, utilizing a single depolarizing conductance and leak conductances for repolarizing the ORN, was derived from the first version. It served to analyze the effects on the sensory properties of varying the electrical parameters and the size of the main sensillum parts. The consequences of the results obtained on the still uncertain mechanisms of Olfactory transduction in moth ORNs - involvement or not of G-proteins, role of chloride and potassium currents - are discussed as well as the optimality of the sensillum organization, the dependence of biochemical parameters on the Neuron spatial extension and the respective contributions of the biochemical and electrical parameters to the overall Neuron response.
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Calcium activates a chloride conductance likely involved in Olfactory Receptor Neuron repolarization in the moth Spodoptera littoralis
Journal of Neuroscience, 2010Co-Authors: Adeline Pezier, Jean-pierre Rospars, Christelle Monsempes, Marta Grauso, Adrien Acquistapace, Philippe LucasAbstract:The response of insect Olfactory Receptor Neurons (ORNs) to odorants involves the opening of Ca2+-permeable channels, generating an increase in intracellular Ca2+ concentration. Here, we studied the downstream effect of this Ca2+ rise in cultured ORNs of the moth Spodoptera littoralis. Intracellular dialysis of Ca2+ from the patch pipette in whole-cell patch-clamp configuration activated a conductance with a K-1/2 of 2.8 mu M. Intracellular and extracellular anionic and cationic substitutions demonstrated that Cl- carries this current. The anion permeability sequence I- > NO3- > Br- > Cl- > CH3SO(3)(-) >> gluconate(-) of the Ca2+-activated Cl- channel suggests a weak electrical field pore of the channel. The Ca2+-activated current partly inactivated over time and did not depend on protein kinase C (PKC) and CaMKII activity or on calmodulin. Application of Cl- channel blockers, flufenamic acid, 5-nitro-2-(3-phenylpropylamino) benzoic acid, or niflumic acid reversibly blocked the Ca2+-activated current. In addition, lowering Cl- concentration in the sensillar lymph bathing the ORN outer dendrites caused a significant delay in pheromone response termination in vivo. The present work identifies a new Cl- conductance activated by Ca2+ in insect ORNs presumably required for ORN repolarization.
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Selectivity improvement in a model of Olfactory Receptor Neuron with adsorption-desorption noise
Journal of Biological Systems, 2008Co-Authors: Alexander Vidybida, A.s. Usenko, Jean-pierre RosparsAbstract:In biological Olfactory systems, interaction of odorant molecules with Olfactory Receptor proteins is driven by Brownian motion. As a result, at chemical equilibrium, the total number of bound Receptors changes randomly in time. Here we investigate the role of this effect, known in physics as adsorption-desorption noise, in the discriminating ability of Olfactory Receptor Neurons. For this purpose we developed a computer program, which generates the adsorption-desorption process in a model Neuron. We compared the processes resulting from two different odorants with different affinities for the Receptor proteins. We took into account the threshold at which spikes are triggered and we calculated the Neuronal selectivity due to the differences in the threshold-crossing statistics for the processes resulting from both odorants. We conclude that selectivity of the spiking response of the whole Neuron is much greater than that of its Receptor proteins in the near-threshold range of odorant concentrations.
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quantitative analysis of Olfactory Receptor Neuron projections in the antennal lobe of the malaria mosquito anopheles gambiae
The Journal of Comparative Neurology, 2004Co-Authors: Sylvia Anton, Jean-pierre RosparsAbstract:Mosquitoes are highly dependent on the Olfactory sense to find their hosts. How Olfactory information concerning host odors is represented and processed in the brain to elicit Olfactory guided behavior is not known. We present an exploratory analysis of central projections of Olfactory Receptor Neurons originating from antennal and maxillary palp sensilla known to be involved in the detection of host odors in the malaria mosquito, Anopheles gambiae. We developed computational neuroanatomic methods to determine quantitatively the positions of Olfactory Receptor Neuron terminal arborizations and compare them between brains. These quantitative analyses suggested the existence of five nonoverlapping projection zones within the antennal lobe, with one zone receiving exclusive input from maxillary palp sensilla and two zones each receiving exclusive input from trichoid or grooved-peg antennal sensilla. Projection patterns were not found to depend significantly on the odorants used during the staining procedure. The separate zones receiving input from different sensillum types seemed to represent a functional segregation because Olfactory Receptor Neurons present in the different sensilla differed in their response profiles. J. Comp. Neurol. 475:315–326, 2004. © 2004 Wiley-Liss, Inc.
