1
|
Arrestin-mediated desensitization enables intraneuronal olfactory discrimination in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2022; 119:e2116957119. [PMID: 35878038 PMCID: PMC9351366 DOI: 10.1073/pnas.2116957119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In the mammalian olfactory system, cross-talk between olfactory signals is minimized through physical isolation: individual neurons express one or few olfactory receptors among those encoded in the genome. Physical isolation allows for segregation of stimuli during signal transduction; however, in the nematode worm Caenorhabditis elegans, ∼1,300 olfactory receptors are primarily expressed in only 32 neurons, precluding this strategy. Here, we report genetic and behavioral evidence that β-arrestin-mediated desensitization of olfactory receptors, working downstream of the kinase GRK-1, enables discrimination between intraneuronal olfactory stimuli. Our findings suggest that C. elegans exploits β-arrestin desensitization to maximize responsiveness to novel odors, allowing for behaviorally appropriate responses to olfactory stimuli despite the large number of olfactory receptors signaling in single cells. This represents a fundamentally different solution to the problem of olfactory discrimination than that which evolved in mammals, allowing for economical use of a limited number of sensory neurons.
Collapse
|
2
|
Zabihihesari A, Hilliker AJ, Rezai P. Fly-on-a-Chip: Microfluidics for Drosophila melanogaster Studies. Integr Biol (Camb) 2020; 11:425-443. [DOI: 10.1093/intbio/zyz037] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/21/2019] [Accepted: 10/26/2019] [Indexed: 12/16/2022]
Abstract
Abstract
The fruit fly or Drosophila melanogaster has been used as a promising model organism in genetics, developmental and behavioral studies as well as in the fields of neuroscience, pharmacology, and toxicology. Not only all the developmental stages of Drosophila, including embryonic, larval, and adulthood stages, have been used in experimental in vivo biology, but also the organs, tissues, and cells extracted from this model have found applications in in vitro assays. However, the manual manipulation, cellular investigation and behavioral phenotyping techniques utilized in conventional Drosophila-based in vivo and in vitro assays are mostly time-consuming, labor-intensive, and low in throughput. Moreover, stimulation of the organism with external biological, chemical, or physical signals requires precision in signal delivery, while quantification of neural and behavioral phenotypes necessitates optical and physical accessibility to Drosophila. Recently, microfluidic and lab-on-a-chip devices have emerged as powerful tools to overcome these challenges. This review paper demonstrates the role of microfluidic technology in Drosophila studies with a focus on both in vivo and in vitro investigations. The reviewed microfluidic devices are categorized based on their applications to various stages of Drosophila development. We have emphasized technologies that were utilized for tissue- and behavior-based investigations. Furthermore, the challenges and future directions in Drosophila-on-a-chip research, and its integration with other advanced technologies, will be discussed.
Collapse
Affiliation(s)
| | | | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, ON, Canada
| |
Collapse
|
3
|
Schleyer M, Fendt M, Schuller S, Gerber B. Associative Learning of Stimuli Paired and Unpaired With Reinforcement: Evaluating Evidence From Maggots, Flies, Bees, and Rats. Front Psychol 2018; 9:1494. [PMID: 30197613 PMCID: PMC6117914 DOI: 10.3389/fpsyg.2018.01494] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/30/2018] [Indexed: 12/02/2022] Open
Abstract
Finding rewards and avoiding punishments are powerful goals of behavior. To maximize reward and minimize punishment, it is beneficial to learn about the stimuli that predict their occurrence, and decades of research have provided insight into the brain processes underlying such associative reinforcement learning. In addition, it is well known in experimental psychology, yet often unacknowledged in neighboring scientific disciplines, that subjects also learn about the stimuli that predict the absence of reinforcement. Here we evaluate evidence for both these learning processes. We focus on two study cases that both provide a baseline level of behavior against which the effects of associative learning can be assessed. Firstly, we report pertinent evidence from Drosophila larvae. A re-analysis of the literature reveals that through paired presentations of an odor A and a sugar reward (A+) the animals learn that the reward can be found where the odor is, and therefore show an above-baseline preference for the odor. In contrast, through unpaired training (A/+) the animals learn that the reward can be found precisely where the odor is not, and accordingly these larvae show a below-baseline preference for it (the same is the case, with inverted signs, for learning through taste punishment). In addition, we present previously unpublished data demonstrating that also during a two-odor, differential conditioning protocol (A+/B) both these learning processes take place in larvae, i.e., learning about both the rewarded stimulus A and the non-rewarded stimulus B (again, this is likewise the case for differential conditioning with taste punishment). Secondly, after briefly discussing published evidence from adult Drosophila, honeybees, and rats, we report an unpublished data set showing that relative to baseline behavior after truly random presentations of a visual stimulus A and punishment, rats exhibit memories of opposite valence upon paired and unpaired training. Collectively, the evidence conforms to classical findings in experimental psychology and suggests that across species animals associatively learn both through paired and through unpaired presentations of stimuli with reinforcement – with opposite valence. While the brain mechanisms of unpaired learning for the most part still need to be uncovered, the immediate implication is that using unpaired procedures as a mnemonically neutral control for associative reinforcement learning may be leading analyses astray.
Collapse
Affiliation(s)
- Michael Schleyer
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Markus Fendt
- Institute for Pharmacology and Toxicology, Otto von Guericke University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Sarah Schuller
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Bertram Gerber
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Behavior Genetics, Institute for Biology, Otto von Guericke University Magdeburg, Magdeburg, Germany
| |
Collapse
|
4
|
Sfara V, Mougabure-Cueto GA, González-Audino PA. Modulation of the behavioral and electrical responses to the repellent DEET elicited by the pre-exposure to the same compound in Blattella germanica. PeerJ 2016; 4:e2150. [PMID: 27375967 PMCID: PMC4928467 DOI: 10.7717/peerj.2150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/27/2016] [Indexed: 11/20/2022] Open
Abstract
Insects under different stimuli from the environment modify behavioural responses due to changes in the sensitivity of neurons at the peripheral and/or at the central level of the nervous system. This phenomenon is called neuronal plasticity, and sensory adaptation is an example of it. An insect repellent is a chemical that produces oriented movements of the insects away from its source. In this work we studied the modulation of the behavioural and electrical response to the repellent N, N-diethyl-3-methylbenzamide (DEET) in males of the German cockroach B. germanica produced by previous exposure to the same repellent. Methods. We determined repellency using a circular arena, one half of which was treated with DEET. The time spent by insects in each half of the arena was measured, and a repellency coefficient (RC) was calculated. The RCs of pre-exposed and non-pre-exposed insects were compared. To determine a possible role of nitric oxide in the modulation of the response to DEET after pre-exposure, the nitric oxide donor S-nitroso-acetyl-cysteine (SNAC) was applied on cockroaches’ antennae. The electrical activity of the cockroaches’ antennae in response to DEET was recorded using electroantennogram (EAG) technique. The response to DEET was recorded also after a long stimulation with the same repellent, and after topical application of SNAC and dbcGMP (a cGMP analogue) on the antennae. Results. We found that previous exposure of B. germanica males to the repellent DEET produced an increase of the repellency at the behavioural level, measured as RC. A possible role of nitric oxide (NO) in the transduction pathway of this phenomenon is suggested, since treatment of the cockroaches with the NO donor SNAC also produced an increase of the repellency elicited by DEET. On the other hand, the response of the cockroaches’ antennae exposed to DEET was determined electrophysiologically. The electrical activity in response to DEET decreased when the insects’ antennae were stimulated with a long pulse of the repellent. The activity of the antennae was restored after 10 min. Treatment of the antennae either with SNAC or dbGMPc also produced a decrease in the response of the antennae to the repellent. Discussion.The previous exposure to a chemical stimulus can modify the behaviour associated to the same stimulus, increasing or decreasing the behavioural response. In the case of DEET we found that pre-exposure increased DEET repellency in male cockroaches. We also found NO involvement in a similar phenomenon. On the other hand, the test showed that DEET is perceived by insects’ antennae as an odour. A long exposure of the antennae to DEET caused a transient decrease in the response of the antennae to the same compound. The same effect was achieved by treating the antennae with SNAC or dbcGMP, suggesting the involvement of the NO/cGMP system in the transduction pathway of the sensory adaptation phenomenon elicited by an odour in this species.
Collapse
Affiliation(s)
- Valeria Sfara
- Instituto de Investigación e Ingeniería Ambiental (3iA), Universidad Nacional de San Martín (UNSAM) , San Martín, Buenos Aires , Argentina
| | - Gastón A Mougabure-Cueto
- Centro de Referencia de Vectores (CeReVe), Ministerio de Salud de la Nación , Santa María de Punilla , Córdoba , Argentina
| | - Paola A González-Audino
- Centro de Investigaciones de Plagas e Insecticidas (CIPEIN-UNIDEF-CONICET) , Buenos Aires , Argentina
| |
Collapse
|
5
|
Ardeshiri R, Hosseini L, Amini N, Rezai P. Cardiac screening of intact Drosophila melanogaster larvae under exposure to aqueous and gaseous toxins in a microfluidic device. RSC Adv 2016. [DOI: 10.1039/c6ra14159e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We present a semi-automated microfluidic chip for orientation, immobilization, chemical exposure, and cardiac screening of 3rd instar Drosophila melanogaster larvae.
Collapse
Affiliation(s)
- R. Ardeshiri
- Department of Mechanical Engineering
- York University
- Toronto
- Canada
| | - L. Hosseini
- Department of Mechanical Engineering
- York University
- Toronto
- Canada
| | - N. Amini
- Department of Mechanical Engineering
- York University
- Toronto
- Canada
| | - P. Rezai
- Department of Mechanical Engineering
- York University
- Toronto
- Canada
| |
Collapse
|
6
|
Abstract
Adverse life events can induce two kinds of memory with opposite valence, dependent on timing: "negative" memories for stimuli preceding them and "positive" memories for stimuli experienced at the moment of "relief." Such punishment memory and relief memory are found in insects, rats, and man. For example, fruit flies (Drosophila melanogaster) avoid an odor after odor-shock training ("forward conditioning" of the odor), whereas after shock-odor training ("backward conditioning" of the odor) they approach it. Do these timing-dependent associative processes share molecular determinants? We focus on the role of Synapsin, a conserved presynaptic phosphoprotein regulating the balance between the reserve pool and the readily releasable pool of synaptic vesicles. We find that a lack of Synapsin leaves task-relevant sensory and motor faculties unaffected. In contrast, both punishment memory and relief memory scores are reduced. These defects reflect a true lessening of associative memory strength, as distortions in nonassociative processing (e.g., susceptibility to handling, adaptation, habituation, sensitization), discrimination ability, and changes in the time course of coincidence detection can be ruled out as alternative explanations. Reductions in punishment- and relief-memory strength are also observed upon an RNAi-mediated knock-down of Synapsin, and are rescued both by acutely restoring Synapsin and by locally restoring it in the mushroom bodies of mutant flies. Thus, both punishment memory and relief memory require the Synapsin protein and in this sense share genetic and molecular determinants. We note that corresponding molecular commonalities between punishment memory and relief memory in humans would constrain pharmacological attempts to selectively interfere with excessive associative punishment memories, e.g., after traumatic experiences.
Collapse
|
7
|
Schleyer M, Reid SF, Pamir E, Saumweber T, Paisios E, Davies A, Gerber B, Louis M. The impact of odor-reward memory on chemotaxis in larval Drosophila. ACTA ACUST UNITED AC 2015; 22:267-77. [PMID: 25887280 PMCID: PMC4408773 DOI: 10.1101/lm.037978.114] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 03/16/2015] [Indexed: 01/29/2023]
Abstract
How do animals adaptively integrate innate with learned behavioral tendencies? We tackle this question using chemotaxis as a paradigm. Chemotaxis in the Drosophila larva largely results from a sequence of runs and oriented turns. Thus, the larvae minimally need to determine (i) how fast to run, (ii) when to initiate a turn, and (iii) where to direct a turn. We first report how odor-source intensities modulate these decisions to bring about higher levels of chemotactic performance for higher odor-source intensities during innate chemotaxis. We then examine whether the same modulations are responsible for alterations of chemotactic performance by learned odor “valence” (understood throughout as level of attractiveness). We find that run speed (i) is neither modulated by the innate nor by the learned valence of an odor. Turn rate (ii), however, is modulated by both: the higher the innate or learned valence of the odor, the less often larvae turn whenever heading toward the odor source, and the more often they turn when heading away. Likewise, turning direction (iii) is modulated concordantly by innate and learned valence: turning is biased more strongly toward the odor source when either innate or learned valence is high. Using numerical simulations, we show that a modulation of both turn rate and of turning direction is sufficient to account for the empirically found differences in preference scores across experimental conditions. Our results suggest that innate and learned valence organize adaptive olfactory search behavior by their summed effects on turn rate and turning direction, but not on run speed. This work should aid studies into the neural mechanisms by which memory impacts specific aspects of behavior.
Collapse
Affiliation(s)
- Michael Schleyer
- Leibniz Institute for Neurobiology (LIN), Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Samuel F Reid
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Evren Pamir
- Leibniz Institute for Neurobiology (LIN), Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Timo Saumweber
- Leibniz Institute for Neurobiology (LIN), Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Emmanouil Paisios
- Leibniz Institute for Neurobiology (LIN), Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Alexander Davies
- University of Edinburgh, School of Informatics, Edinburgh EH8 9AB, United Kingdom
| | - Bertram Gerber
- Leibniz Institute for Neurobiology (LIN), Department Genetics of Learning and Memory, 39118 Magdeburg, Germany Otto von Guericke University Magdeburg, Institute for Biology, Behavior Genetics, 39106 Magdeburg, Germany Center of Behavioural Brain Science (CBBS), Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Matthieu Louis
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| |
Collapse
|
8
|
Chen YC, Gerber B. Generalization and discrimination tasks yield concordant measures of perceived distance between odours and their binary mixtures in larval Drosophila. ACTA ACUST UNITED AC 2015; 217:2071-7. [PMID: 24920835 PMCID: PMC4191342 DOI: 10.1242/jeb.100966] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Similarity between odours is notoriously difficult to measure. Widely used behavioural approaches in insect olfaction research are cross-adaptation, masking, as well as associative tasks based on olfactory learning and the subsequent testing for how specific the established memory is. A concern with such memory-based approaches is that the learning process required to establish an odour memory may alter the way the odour is processed, such that measures of perception taken at the test are distorted. The present study was therefore designed to see whether behavioural judgements of perceptual distance are different for two different memory-based tasks, namely generalization and discrimination. We used odour–reward learning in larval Drosophila as a study case. In order to challenge the larvae's olfactory system, we chose to work with binary mixtures and their elements (1-octanol, n-amyl acetate, 3-octanol, benzaldehyde and hexyl acetate). We determined the perceptual distance between each mixture and its elements, first in a generalization task, and then in a discrimination task. It turns out that scores of perceptual distance are correlated between both tasks. A re-analysis of published studies looking at element-to-element perceptual distances in larval reward learning and in adult punishment learning confirms this result. We therefore suggest that across a given set of olfactory stimuli, associative training does not grossly alter the pattern of perceptual distances.
Collapse
Affiliation(s)
- Yi-chun Chen
- Universität Würzburg, Biozentrum, Lehrstuhl für Genetik und Neurobiologie, 97074 Würzburg, Germany
| | - Bertram Gerber
- Universität Würzburg, Biozentrum, Lehrstuhl für Genetik und Neurobiologie, 97074 Würzburg, Germany Otto von Guericke Universität Magdeburg, Institut für Biologie, Verhaltensgenetik, 39106 Magdeburg, Germany Center for Behavioral Brain Science (CBBS), 39106 Magdeburg, Germany Leibniz Institut für Neurobiologie (LIN), Abteilung Genetik von Lernen und Gedächtnis, 39118 Magdeburg, Germany
| |
Collapse
|
9
|
Grewal JS, Nguyen C, Robles R, Cho C, Kir K, Fledderman N, Gacharna G, Wesolowski M, Klinger C, Vallejo P, Menhennett L, Nagaraj A, Ebo C, Peacy G, Davelis E, Kucher D, Giers S, Kreher SA. Complex and non-redundant signals from individual odor receptors that underlie chemotaxis behavior in Drosophila melanogaster larvae. Biol Open 2014; 3:947-57. [PMID: 25238759 PMCID: PMC4197443 DOI: 10.1242/bio.20148573] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The rules by which odor receptors encode odors and allow behavior are still largely unexplored. Although large data sets of electrophysiological responses of receptors to odors have been generated, few hypotheses have been tested with behavioral assays. We use a data set on odor responses of Drosophila larval odor receptors coupled with chemotaxis behavioral assays to examine rules of odor coding. Using mutants of odor receptors, we have found that odor receptors with similar electrophysiological responses to odors across concentrations play non-redundant roles in odor coding at specific odor concentrations. We have also found that high affinity receptors for odors determine behavioral response thresholds, but the rules for determining peak behavioral responses are more complex. While receptor mutants typically show loss of attraction to odors, some receptor mutants result in increased attraction at specific odor concentrations. The odor receptor mutants were rescued using transgenic expression of odor receptors, validating assignment of phenotypes to the alleles. Vapor pressures alone cannot fully explain behavior in our assay. Finally, some odors that did not elicit strong electrophysiological responses are associated with behavioral phenotypes upon examination of odor receptor mutants. This result is consistent with the role of sensory neurons in lateral inhibition via local interneurons in the antennal lobe. Taken together, our results suggest a complexity of odor coding rules even in a simple olfactory sensory system.
Collapse
Affiliation(s)
- Jeewanjot S Grewal
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Christine Nguyen
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Raquel Robles
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Christina Cho
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Karolina Kir
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Nicole Fledderman
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - George Gacharna
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Michael Wesolowski
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Christie Klinger
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Pedro Vallejo
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Lorien Menhennett
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Abhiram Nagaraj
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Chineze Ebo
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Garrett Peacy
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Eftihia Davelis
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - David Kucher
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Sarah Giers
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| | - Scott A Kreher
- Department of Biological Sciences, Dominican University, 7900 West Division Street, Parmer Hall 244, River Forest, IL 60305, USA
| |
Collapse
|
10
|
Abstract
The ability of organisms to seamlessly ignore familiar, inconsequential stimuli improves their selective attention and response to salient features of the environment. Here, I propose that this fundamental but unexplained phenomenon substantially derives from the ability of any pattern of neural excitation to create an enhanced inhibitory (or "negative") image of itself through target-specific scaling of inhibitory inputs onto active excitatory neurons. Familiar stimuli encounter strong negative images and are therefore less likely to be transmitted to higher brain centers. Integrating historical and recent observations, the negative-image model described here provides a mechanistic framework for understanding habituation, which is connected to ideas on dynamic predictive coding. In addition, it suggests insights for understanding autism spectrum disorders.
Collapse
|
11
|
Lutz A, Sfara V, Alzogaray RA. Repellence produced by monoterpenes on Rhodnius prolixus (Hemiptera: Reduviidae) decreases after continuous exposure to these compounds. JOURNAL OF INSECT SCIENCE (ONLINE) 2014; 14:254. [PMID: 25525113 PMCID: PMC5634126 DOI: 10.1093/jisesa/ieu116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 02/18/2014] [Indexed: 06/04/2023]
Abstract
Botanical monoterpenes are secondary metabolites present in essential oils produced by plants. Some of them are insect repellents. The bloodsucking bug Rhodnius prolixus Ståhl (Hemiptera: Reduviidae) is one of the main vectors of Chagas disease in the north of South America and some countries in Central America. In this study, we studied the repellence produced by two monoterpenes, menthyl acetate and geraniol, on fifth instar nymphs of R. prolixus. In the absence of other stimuli, both menthyl acetate and geraniol produced a repellent effect from 740 μg/cm(2) and 74 μg/cm(2), respectively. Pre-exposure to each monoterpene reduced the repellent activity produced by the same substance. Additionally, pre-exposure to one monoterpene decreased the behavioral response of the nymphs to the other one. The repellent effect of both monoterpenes also decreased when nymphs' antennae were previously treated with the nitric oxide donor S-nitroso-N-acetyl-cysteine.
Collapse
Affiliation(s)
- Alejandra Lutz
- Cátedra de Sanidad Vegetal, Departamento de Producción Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional del Litoral, Provincia de Santa Fe, Argentina
| | - Valeria Sfara
- Centro de Investigaciones de Plagas e Insecticidas (CIPEIN-UNIDEF-CONICET), JB de La Salle 4397, (1603) Villa Martelli, Provincia de Buenos Aires, Argentina Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, San Martín, Provincia de Buenos Aires, Argentina
| | - Raúl Adolfo Alzogaray
- Centro de Investigaciones de Plagas e Insecticidas (CIPEIN-UNIDEF-CONICET), JB de La Salle 4397, (1603) Villa Martelli, Provincia de Buenos Aires, Argentina Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, San Martín, Provincia de Buenos Aires, Argentina
| |
Collapse
|
12
|
Lavagnino NJ, Arya GH, Korovaichuk A, Fanara JJ. Genetic architecture of olfactory behavior in Drosophila melanogaster: differences and similarities across development. Behav Genet 2013; 43:348-59. [PMID: 23563598 PMCID: PMC3691330 DOI: 10.1007/s10519-013-9592-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 03/18/2013] [Indexed: 01/22/2023]
Abstract
In the holometabolous insect Drosophila melanogaster, genetic, physiological and anatomical aspects of olfaction are well known in the adult stage, while larval stages olfactory behavior has received some attention it has been less studied than its adult counterpart. Most of these studies focus on olfactory receptor (Or) genes that produce peripheral odor recognition. In this paper, through a loss-of-function screen using P-element inserted lines and also by means of expression analyses of larval olfaction candidate genes, we extended the uncovering of the genetic underpinnings of D. melanogaster larval olfactory behavior by demonstrating that larval olfactory behavior is, in addition to Or genes, orchestrated by numerous genes with diverse functions. Also, our results point out that the genetic architecture of olfactory behavior in D. melanogaster presents a dynamic and changing organization across environments and ontogeny.
Collapse
Affiliation(s)
- N J Lavagnino
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina.
| | | | | | | |
Collapse
|
13
|
Abstract
We studied complete dose-response curves for 53 odorants in the third instar larvae of Drosophila melanogaster. All odorants, except one, elicited an attraction response. Some odorants also elicited a decrease from their peak response at higher concentrations. This concentration-dependent decrease in olfactory response could be due to either desensitization or repulsion, 2 possibilities that we cannot distinguish in our current assay. We observed high variations in factors like slopes, thresholds, and peaks of responses that, in agreement with previous studies, suggest that the responses of different receptors are quite different for the similar change in concentration of various ligands. We also observed that lower attraction thresholds predicted higher peak amplitude. This suggests that if odor responses encompassed wider concentration range than can be covered by the dynamic range of a single receptor, then responses tend to be high in magnitude.
Collapse
Affiliation(s)
- Sukant Khurana
- National Center for Biological Sciences, GKVK Campus, Bangalore, Karnataka, India.
| | | |
Collapse
|
14
|
Sfara V, Mougabure-Cueto G, Zerba EN, Alzogaray RA. Adaptation of the repellency response to DEET in Rhodnius prolixus. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:1431-1436. [PMID: 21801727 DOI: 10.1016/j.jinsphys.2011.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 07/08/2011] [Accepted: 07/13/2011] [Indexed: 05/31/2023]
Abstract
For many years it has been accepted that DEET interferes with the detection of odours from the host instead of having a repellent effect. However, recent work showed that DEET acts as an odorant molecule and elicits a behavioural response in the absence of other stimuli. Therefore, DEET must promote some phenomenon connected with the stimuli-sensory system interaction, such as a sensory adaptation, where the sensory system regulates its sensitivity to different stimuli intensities during continuous or repetitive exposure. In this work, we studied different aspects of the insect-DEET interaction through behavioural observations. Previous exposure of fifth instar Rhodnius prolixus nymphs to DEET decreased the behavioural response to this repellent. We observed a decrease in repellence after different times of continuous stimulation with DEET in a time-dependent manner. The response to DEET was recovered 10 min after exposure, when insects were continuously stimulated during 5 or 10 min; maximum repellence was recovered 20 min after exposure when insects were stimulated for 20 min. DEET produced a repellent effect when nymphs were exposed only to its vapours. These results suggest that exposure to DEET produces adaptation in R. prolixus nymphs, and that the behavioural response elicited by DEET occurs via olfaction when no other stimuli are present.
Collapse
Affiliation(s)
- Valeria Sfara
- Centro de Investigaciones de Plagas e Insecticidas (CONICET), Juan Bautista de La Salle 4397, Buenos Aires, Argentina.
| | | | | | | |
Collapse
|
15
|
Schleyer M, Saumweber T, Nahrendorf W, Fischer B, von Alpen D, Pauls D, Thum A, Gerber B. A behavior-based circuit model of how outcome expectations organize learned behavior in larval Drosophila. Learn Mem 2011; 18:639-53. [PMID: 21946956 DOI: 10.1101/lm.2163411] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Drosophila larvae combine a numerically simple brain, a correspondingly moderate behavioral complexity, and the availability of a rich toolbox for transgenic manipulation. This makes them attractive as a study case when trying to achieve a circuit-level understanding of behavior organization. From a series of behavioral experiments, we suggest a circuitry of chemosensory processing, odor-tastant memory trace formation, and the "decision" process to behaviorally express these memory traces--or not. The model incorporates statements about the neuronal organization of innate vs. conditioned chemosensory behavior, and the types of interaction between olfactory and gustatory pathways during the establishment as well as the behavioral expression of odor-tastant memory traces. It in particular suggests that innate olfactory behavior is responsive in nature, whereas conditioned olfactory behavior is captured better when seen as an action in pursuit of its outcome. It incorporates the available neuroanatomical and behavioral data and thus should be useful as scaffold for the ongoing investigations of the chemo-behavioral system in larval Drosophila.
Collapse
Affiliation(s)
- Michael Schleyer
- Universität Würzburg, Biozentrum, Neurobiologie und Genetik, Am Hubland, 970 74 Würzburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Plasticity of local GABAergic interneurons drives olfactory habituation. Proc Natl Acad Sci U S A 2011; 108:E646-54. [PMID: 21795607 DOI: 10.1073/pnas.1106411108] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Despite its ubiquity and significance, behavioral habituation is poorly understood in terms of the underlying neural circuit mechanisms. Here, we present evidence that habituation arises from potentiation of inhibitory transmission within a circuit motif commonly repeated in the nervous system. In Drosophila, prior odorant exposure results in a selective reduction of response to this odorant. Both short-term (STH) and long-term (LTH) forms of olfactory habituation require function of the rutabaga-encoded adenylate cyclase in multiglomerular local interneurons (LNs) that mediate GABAergic inhibition in the antennal lobe; LTH additionally requires function of the cAMP response element-binding protein (CREB2) transcription factor in LNs. The odorant selectivity of STH and LTH is mirrored by requirement for NMDA receptors and GABA(A) receptors in odorant-selective, glomerulus-specific projection neurons(PNs). The need for the vesicular glutamate transporter in LNs indicates that a subset of these GABAergic neurons also releases glutamate. LTH is associated with a reduction of odorant-evoked calcium fluxes in PNs as well as growth of the respective odorant-responsive glomeruli. These cellular changes use similar mechanisms to those required for behavioral habituation. Taken together with the observation that enhancement of GABAergic transmission is sufficient to attenuate olfactory behavior, these data indicate that habituation arises from glomerulus-selective potentiation of inhibitory synapses in the antennal lobe. We suggest that similar circuit mechanisms may operate in other species and sensory systems.
Collapse
|
17
|
Mishra D, Louis M, Gerber B. Adaptive adjustment of the generalization-discrimination balance in larval Drosophila. J Neurogenet 2011; 24:168-75. [PMID: 20807100 DOI: 10.3109/01677063.2010.498066] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Learnt predictive behavior faces a dilemma: predictive stimuli will never 'replay' exactly as during the learning event, requiring generalization. In turn, minute differences can become meaningful, prompting discrimination. To provide a study case for an adaptive adjustment of this generalization-discrimination balance, the authors ask whether Drosophila melanogaster larvae are able to either generalize or discriminate between two odors (1-octen-3-ol and 3-octanol), depending on the task. The authors find that after discriminatively rewarding one but not the other odor, larvae show conditioned preference for the rewarded odor. On the other hand, no odor specificity is observed after nondiscriminative training, even if the test involves a choice between both odors. Thus, for this odor pair at least, discrimination training is required to confer an odor-specific memory trace. This requires that there is at least some difference in processing between the two odors already at the beginning of the training. Therefore, as a default, there is a small yet salient difference in processing between 1-octen-3-ol and 3-octanol; this difference is ignored after nondiscriminative training (generalization), whereas it is accentuated by odor-specific reinforcement (discrimination). Given that, as the authors show, both faculties are lost in anosmic Or83b(1) mutants, this indicates an adaptive adjustment of the generalization-discrimination balance in larval Drosophila, taking place downstream of Or83b-expressing sensory neurons.
Collapse
Affiliation(s)
- Dushyant Mishra
- Biozentrum Am Hubland, Lehrstuhl für Neurobiologie und Genetik, Universität Würzburg, Würzburg, Germany
| | | | | |
Collapse
|
18
|
Störtkuhl KF, Fiala A. The Smell of Blue Light: A New Approach toward Understanding an Olfactory Neuronal Network. Front Neurosci 2011; 5:72. [PMID: 21647413 PMCID: PMC3103046 DOI: 10.3389/fnins.2011.00072] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 05/06/2011] [Indexed: 11/13/2022] Open
Abstract
Olfaction is one of the most important senses throughout the animal kingdom. It enables animals to discriminate between a wide variety of attractive and repulsive odorants and often plays a decisive role in species specific communication. In recent years the analysis of olfactory systems both invertebrates and invertebrates has attracted much scientific interest. In this context a pivotal question is how the properties and connectivities of individual neurons contribute to a functioning neuronal network that mediates odor-guided behavior. As a novel approach to analyze the role of individual neurons within a circuitry, techniques have been established that make use of light-sensitive proteins. In this review we introduce a non-invasive, optogenetic technique which was used to manipulate the activity of individual neurons in the olfactory system of Drosophila melanogaster larvae. Both channelrhodopsin-2 and the photosensitive adenylyl cyclase PAC α in individual olfactory receptor neurons (ORNs) of the olfactory system of Drosophila larvae allows stimulating individual receptor neurons by light. Depending on which particular ORN is optogenetically activated, repulsion or attraction behavior can be induced, indicating which sensory neurons underlie which type of behavior.
Collapse
Affiliation(s)
- Klemens F Störtkuhl
- AG Physiology of Senses, Department of Biology and Biotechnology, Ruhr University Bochum Bochum, Germany
| | | |
Collapse
|
19
|
Abstract
The synapse-associated protein of 47 kDa (SAP47) is a member of a phylogenetically conserved gene family of hitherto unknown function. In Drosophila, SAP47 is encoded by a single gene (Sap47) and is expressed throughout all synaptic regions of the wild-type larval brain; specifically, electron microscopy reveals anti-SAP47 immunogold labeling within 30 nm of presynaptic vesicles. To analyze SAP47 function, we used the viable and fertile deletion mutant Sap47(156), which suffers from a 1.7 kb deletion in the regulatory region and the first exon. SAP47 cannot be detected by either immunoblotting or immunohistochemistry in Sap47(156) mutants. These mutants exhibit normal sensory detection of odorants and tastants as well as normal motor performance and basic neurotransmission at the neuromuscular junction. However, short-term plasticity at this synapse is distorted. Interestingly, Sap47(156) mutant larvae also show a 50% reduction in odorant-tastant associative learning ability; a similar associative impairment is observed in a second deletion allele (Sap47(201)) and upon reduction of SAP47 levels using RNA interference. In turn, transgenically restoring SAP47 in Sap47(156) mutant larvae rescues the defect in associative function. This report thus is the first to suggest a function for SAP47. It specifically argues that SAP47 is required for proper behavioral and synaptic plasticity in flies-and prompts the question whether its homologs are required for proper behavioral and synaptic plasticity in other species as well.
Collapse
|
20
|
Saumweber T, Husse J, Gerber B. Innate attractiveness and associative learnability of odors can be dissociated in larval Drosophila. Chem Senses 2011; 36:223-35. [PMID: 21227902 PMCID: PMC3038274 DOI: 10.1093/chemse/bjq128] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2010] [Indexed: 12/25/2022] Open
Abstract
We investigate olfactory associative learning in larval Drosophila. A reciprocal training design is used, such that one group of animals receives a reward in the presence of odor X but not in the presence of odor Y (Train: X+ // Y), whereas another group is trained reciprocally (Train: X // Y+). After training, differences in odor preference between these reciprocally trained groups in a choice test (Test: X - Y) reflect associative learning. The current study, after showing which odor pairs can be used for such learning experiments, 1) introduces a one-odor version of such reciprocal paradigm that allows estimating the learnability of single odors. Regarding this reciprocal one-odor paradigm, we show that 2) paired presentations of an odor with a reward increase odor preference above baseline, whereas unpaired presentations of odor and reward decrease odor preference below baseline; this suggests that odors can become predictive either of reward or of reward absence. Furthermore, we show that 3) innate attractiveness and associative learnability can be dissociated. These data deepen our understanding of odor-reward learning in larval Drosophila on the behavioral level, and thus foster its neurogenetic analysis.
Collapse
Affiliation(s)
- Timo Saumweber
- Department of Neurobiology and Genetics, Universität Würzburg, Biozentrum Am Hubland, 97074 Würzburg, Germany
- Department of Genetics, Institute for Biology, Universität Leipzig, Talstr. 33, 04103 Leipzig, Germany
| | - Jana Husse
- Department of Neurobiology and Genetics, Universität Würzburg, Biozentrum Am Hubland, 97074 Würzburg, Germany
- Present address: Max Planck Institut für Biophysikalische Chemie, Abteilung Genetik und Verhalten, Am Faßberg 11, 37077 Göttingen, Germany
| | - Bertram Gerber
- Department of Neurobiology and Genetics, Universität Würzburg, Biozentrum Am Hubland, 97074 Würzburg, Germany
- Department of Genetics, Institute for Biology, Universität Leipzig, Talstr. 33, 04103 Leipzig, Germany
| |
Collapse
|
21
|
Chen YC, Mishra D, Schmitt L, Schmuker M, Gerber B. A behavioral odor similarity "space" in larval Drosophila. Chem Senses 2011; 36:237-49. [PMID: 21227903 PMCID: PMC3038273 DOI: 10.1093/chemse/bjq123] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To provide a behavior-based estimate of odor similarity in larval Drosophila, we use 4 recognition-type experiments: 1) We train larvae to associate an odor with food and then test whether they would regard another odor as the same as the trained one. 2) We train larvae to associate an odor with food and test whether they prefer the trained odor against a novel nontrained one. 3) We train larvae differentially to associate one odor with food, but not the other one, and test whether they prefer the rewarded against the nonrewarded odor. 4) In an experiment like (3), we test the larvae after a 30-min break. This yields a combined task-independent estimate of perceived difference between odor pairs. Comparing these perceived differences to published measures of physicochemical difference reveals a weak correlation. A notable exception are 3-octanol and benzaldehyde, which are distinct in published accounts of chemical similarity and in terms of their published sensory representation but nevertheless are consistently regarded as the most similar of the 10 odor pairs employed. It thus appears as if at least some aspects of olfactory perception are “computed” in postreceptor circuits on the basis of sensory signals rather than being immediately given by them.
Collapse
Affiliation(s)
- Yi-chun Chen
- Department of Neurobiology and Genetics, Universität Würzburg, Biozentrum Am Hubland, 97074 Würzburg, Germany
| | | | | | | | | |
Collapse
|
22
|
Larkin A, Karak S, Priya R, Das A, Ayyub C, Ito K, Rodrigues V, Ramaswami M. Central synaptic mechanisms underlie short-term olfactory habituation in Drosophila larvae. Learn Mem 2010; 17:645-53. [PMID: 21106688 DOI: 10.1101/lm.1839010] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Naive Drosophila larvae show vigorous chemotaxis toward many odorants including ethyl acetate (EA). Chemotaxis toward EA is substantially reduced after a 5-min pre-exposure to the odorant and recovers with a half-time of ∼20 min. An analogous behavioral decrement can be induced without odorant-receptor activation through channelrhodopsin-based, direct photoexcitation of odorant sensory neurons (OSNs). The neural mechanism of short-term habituation (STH) requires the (1) rutabaga adenylate cyclase; (2) transmitter release from predominantly GABAergic local interneurons (LNs); (3) GABA-A receptor function in projection neurons (PNs) that receive excitatory inputs from OSNs; and (4) NMDA-receptor function in PNs. These features of STH cannot be explained by simple sensory adaptation and, instead, point to plasticity of olfactory synapses in the antennal lobe as the underlying mechanism. Our observations suggest a model in which NMDAR-dependent depression of the OSN-PN synapse and/or NMDAR-dependent facilitation of inhibitory transmission from LNs to PNs contributes substantially to short-term habituation.
Collapse
Affiliation(s)
- Aoife Larkin
- School of Genetics and Microbiology, Smurfit Institute of Genetics and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Yarali A, Ehser S, Hapil FZ, Huang J, Gerber B. Odour intensity learning in fruit flies. Proc Biol Sci 2009; 276:3413-20. [PMID: 19586944 DOI: 10.1098/rspb.2009.0705] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Animals' behaviour towards odours depends on both odour quality and odour intensity. While neuronal coding of odour quality is fairly well studied, how odour intensity is treated by olfactory systems is less clear. Here we study odour intensity processing at the behavioural level, using the fruit fly Drosophila melanogaster. We trained flies by pairing a MEDIUM intensity of an odour with electric shock, and then, at a following test phase, measured flies' conditioned avoidance of either this previously trained MEDIUM intensity or a LOWer or a HIGHer intensity. With respect to 3-octanol, n-amylacetate and 4-methylcyclohexanol, we found that conditioned avoidance is strongest when training and test intensities match, speaking for intensity-specific memories. With respect to a fourth odour, benzaldehyde, on the other hand, we found no such intensity specificity. These results form the basis for further studies of odour intensity processing at the behavioural, neuronal and molecular level.
Collapse
|
24
|
The behaviour of Drosophila melanogaster maggots is affected by social, physiological and temporal factors. Anim Behav 2008. [DOI: 10.1016/j.anbehav.2007.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
25
|
|
26
|
Keller A, Vosshall LB. Influence of odorant receptor repertoire on odor perception in humans and fruit flies. Proc Natl Acad Sci U S A 2007; 104:5614-9. [PMID: 17372215 PMCID: PMC1838502 DOI: 10.1073/pnas.0605321104] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The olfactory system is thought to recognize odors with multiple odorant receptors (ORs) that are activated by overlapping sets of odorous molecules, ultimately generating an odor percept in the brain. We investigated how the odor percept differs between humans and Drosophila melanogaster fruit flies, species with very different OR repertoires. We devised high-throughput single fly behavior paradigms to ask how a given OR contributes to the odor percept in Drosophila. Wild-type flies showed dose- and stimulus-dependent responses to 70 of 73 odors tested, whereas mutant flies missing one OR showed subtle behavioral deficits that could not be predicted from the physiological responses of the OR. We measured human and fly judgments of odor intensity and quality and found that intensity perception is conserved between species, whereas quality judgments are species-specific. This study bridges the gap between the activation of olfactory sensory neurons and the odor percept.
Collapse
Affiliation(s)
- Andreas Keller
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, 1230 York Avenue, Box 63, New York, NY 10021
| | - Leslie B. Vosshall
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, 1230 York Avenue, Box 63, New York, NY 10021
- *To whom correspondence should be addressed. E-mail:
| |
Collapse
|
27
|
Gerber B, Stocker RF. The Drosophila larva as a model for studying chemosensation and chemosensory learning: a review. Chem Senses 2006; 32:65-89. [PMID: 17071942 DOI: 10.1093/chemse/bjl030] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Understanding the relationship between brain and behavior is the fundamental challenge in neuroscience. We focus on chemosensation and chemosensory learning in larval Drosophila and review what is known about its molecular and cellular bases. Detailed analyses suggest that the larval olfactory system, albeit much reduced in cell number, shares the basic architecture, both in terms of receptor gene expression and neuronal circuitry, of its adult counterpart as well as of mammals. With respect to the gustatory system, less is known in particular with respect to processing of gustatory information in the central nervous system, leaving generalizations premature. On the behavioral level, a learning paradigm for the association of odors with food reinforcement has been introduced. Capitalizing on the knowledge of the chemosensory pathways, we review the first steps to reveal the genetic and cellular bases of olfactory learning in larval Drosophila. We argue that the simplicity of the larval chemosensory system, combined with the experimental accessibility of Drosophila on the genetic, electrophysiological, cellular, and behavioral level, makes this system suitable for an integrated understanding of chemosensation and chemosensory learning.
Collapse
Affiliation(s)
- Bertram Gerber
- Universität Würzburg, Biozentrum, Am Hubland, Lehrstuhl für Genetik und Neurobiologie, D-97074 Würzburg, Germany.
| | | |
Collapse
|
28
|
van Bergen Y. WHAT'S THAT SMELL? J Exp Biol 2005. [DOI: 10.1242/jeb.01840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|