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Towards plant-odor-related olfactory neuroethology in Drosophila.

Hansson BS, Knaden M, Sachse S, Stensmyr MC, Wicher D - Chemoecology (2009)

Bottom Line: The future challenge is to tie the progress in different fields together to give us a better understanding of how a fly really behaves.Not in a test tube, but in nature.Here, we review our present state of knowledge regarding Drosophila plant-odor-related olfactory neuroethology to provide a basis for new progress.

View Article: PubMed Central - PubMed

Affiliation: Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans Knoell Strasse 8, 07745 Jena, Germany.

ABSTRACT
Drosophila melanogaster is today one of the three foremost models in olfactory research, paralleled only by the mouse and the nematode. In the last years, immense progress has been achieved by combining neurogenetic tools with neurophysiology, anatomy, chemistry, and behavioral assays. One of the most important tasks for a fruit fly is to find a substrate for eating and laying eggs. To perform this task the fly is dependent on olfactory cues emitted by suitable substrates as e.g. decaying fruit. In addition, in this area, considerable progress has been made during the last years, and more and more natural and behaviorally active ligands have been identified. The future challenge is to tie the progress in different fields together to give us a better understanding of how a fly really behaves. Not in a test tube, but in nature. Here, we review our present state of knowledge regarding Drosophila plant-odor-related olfactory neuroethology to provide a basis for new progress.

No MeSH data available.


Related in: MedlinePlus

Odors evoke specific patterns of glomerular activity in the Drosophila antennal lobe. The calcium-sensitive protein G-CaMP has been genetically expressed in either projection neurons (above) or sensory neurons (below). Calcium signals to two different odors have been superimposed onto the morphological image of the antennal lobe. Both odors lead to a specific, but different pattern of activated glomeruli. The activities are bilaterally symmetric between the left and the right antennal lobe. Comparison of the activity patterns between the sensory and the projection neurons to the same odor reveals similar but not identical responses
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Fig3: Odors evoke specific patterns of glomerular activity in the Drosophila antennal lobe. The calcium-sensitive protein G-CaMP has been genetically expressed in either projection neurons (above) or sensory neurons (below). Calcium signals to two different odors have been superimposed onto the morphological image of the antennal lobe. Both odors lead to a specific, but different pattern of activated glomeruli. The activities are bilaterally symmetric between the left and the right antennal lobe. Comparison of the activity patterns between the sensory and the projection neurons to the same odor reveals similar but not identical responses

Mentions: How are odors neuronally represented in the first olfactory neuropil? Optical recording techniques allow visualization of odor-evoked patterns in the AL. Several imaging studies in different insect species using either calcium-sensitive dyes (e.g. Joerges et al. 1997; Galizia et al. 1999; Sachse et al. 1999; Carlsson et al. 2002), genetically encoded reporters to measure intracellular calcium (Fiala et al. 2002; Wang et al. 2003; Silbering et al. 2008) or synaptic vesicle release (Ng et al. 2002; Yu et al. 2004) have shown that odors are encoded as specific spatio-temporal “across-glomeruli” patterns. Each odor evokes activity in several glomeruli, whereas each glomerulus participates in the patterns of several odors (Fig. 3). These activity patterns are species-specific and conserved between different individuals. The olfactory system has in this way developed a strategy to encode a huge number of odors with a limited number of coding units. Although the different studies agree on how odors are encoded, different publications report contradicting results regarding the transformation of odor representations at the different processing levels within the AL (i.e. OSN versus PN responses, Fig. 3). These results reach from sharpening and contrast-enhancement of the olfactory input due to inhibitory processing in honeybees (Sachse and Galizia 2002) to either not processing at all (Ng et al. 2002; Wang et al. 2003) or a broadening of the output pattern in comparison to the input pattern in Dm (Wilson et al. 2004). Adding to the already existing complexity of the AL network, a recently published study in Dm shows that presynaptic inhibition onto OSN terminals leads to an inhibitory network activity (Olsen and Wilson 2008). Odor information processing mechanisms underlying olfactory coding are thus highly diverse and appear to be specific for particular glomerulus-odor combinations (Silbering et al. 2008).Fig. 3


Towards plant-odor-related olfactory neuroethology in Drosophila.

Hansson BS, Knaden M, Sachse S, Stensmyr MC, Wicher D - Chemoecology (2009)

Odors evoke specific patterns of glomerular activity in the Drosophila antennal lobe. The calcium-sensitive protein G-CaMP has been genetically expressed in either projection neurons (above) or sensory neurons (below). Calcium signals to two different odors have been superimposed onto the morphological image of the antennal lobe. Both odors lead to a specific, but different pattern of activated glomeruli. The activities are bilaterally symmetric between the left and the right antennal lobe. Comparison of the activity patterns between the sensory and the projection neurons to the same odor reveals similar but not identical responses
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2864897&req=5

Fig3: Odors evoke specific patterns of glomerular activity in the Drosophila antennal lobe. The calcium-sensitive protein G-CaMP has been genetically expressed in either projection neurons (above) or sensory neurons (below). Calcium signals to two different odors have been superimposed onto the morphological image of the antennal lobe. Both odors lead to a specific, but different pattern of activated glomeruli. The activities are bilaterally symmetric between the left and the right antennal lobe. Comparison of the activity patterns between the sensory and the projection neurons to the same odor reveals similar but not identical responses
Mentions: How are odors neuronally represented in the first olfactory neuropil? Optical recording techniques allow visualization of odor-evoked patterns in the AL. Several imaging studies in different insect species using either calcium-sensitive dyes (e.g. Joerges et al. 1997; Galizia et al. 1999; Sachse et al. 1999; Carlsson et al. 2002), genetically encoded reporters to measure intracellular calcium (Fiala et al. 2002; Wang et al. 2003; Silbering et al. 2008) or synaptic vesicle release (Ng et al. 2002; Yu et al. 2004) have shown that odors are encoded as specific spatio-temporal “across-glomeruli” patterns. Each odor evokes activity in several glomeruli, whereas each glomerulus participates in the patterns of several odors (Fig. 3). These activity patterns are species-specific and conserved between different individuals. The olfactory system has in this way developed a strategy to encode a huge number of odors with a limited number of coding units. Although the different studies agree on how odors are encoded, different publications report contradicting results regarding the transformation of odor representations at the different processing levels within the AL (i.e. OSN versus PN responses, Fig. 3). These results reach from sharpening and contrast-enhancement of the olfactory input due to inhibitory processing in honeybees (Sachse and Galizia 2002) to either not processing at all (Ng et al. 2002; Wang et al. 2003) or a broadening of the output pattern in comparison to the input pattern in Dm (Wilson et al. 2004). Adding to the already existing complexity of the AL network, a recently published study in Dm shows that presynaptic inhibition onto OSN terminals leads to an inhibitory network activity (Olsen and Wilson 2008). Odor information processing mechanisms underlying olfactory coding are thus highly diverse and appear to be specific for particular glomerulus-odor combinations (Silbering et al. 2008).Fig. 3

Bottom Line: The future challenge is to tie the progress in different fields together to give us a better understanding of how a fly really behaves.Not in a test tube, but in nature.Here, we review our present state of knowledge regarding Drosophila plant-odor-related olfactory neuroethology to provide a basis for new progress.

View Article: PubMed Central - PubMed

Affiliation: Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans Knoell Strasse 8, 07745 Jena, Germany.

ABSTRACT
Drosophila melanogaster is today one of the three foremost models in olfactory research, paralleled only by the mouse and the nematode. In the last years, immense progress has been achieved by combining neurogenetic tools with neurophysiology, anatomy, chemistry, and behavioral assays. One of the most important tasks for a fruit fly is to find a substrate for eating and laying eggs. To perform this task the fly is dependent on olfactory cues emitted by suitable substrates as e.g. decaying fruit. In addition, in this area, considerable progress has been made during the last years, and more and more natural and behaviorally active ligands have been identified. The future challenge is to tie the progress in different fields together to give us a better understanding of how a fly really behaves. Not in a test tube, but in nature. Here, we review our present state of knowledge regarding Drosophila plant-odor-related olfactory neuroethology to provide a basis for new progress.

No MeSH data available.


Related in: MedlinePlus