An evaluation of hedonic responses in taste-potentiated odor aversion using the analysis of licking microstructure and orofacial reactivity.

Two experiments examined the hedonic responses conditioned to odor cues in the phenomenon of taste-potentiated odor aversion. Experiment 1 analyzed the microstructure of licking behavior during voluntary consumption. A tasteless odor (amyl acetate) was delivered to rats either diluted in water or mixed with saccharin before being injected with LiCl.

Neuron-glia interaction at the receptor level affects olfactory perception in adult .

Some types of glia play an active role in neuronal signaling by modifying their activity although little is known about their role in sensory information signaling at the receptor level. In this research, we report a functional role for the glia that surround the soma of the olfactory receptor neurons (OSNs) in adult . Specific genetic modifications have been targeted to this cell type to obtain live individuals who are tested for olfactory preference and display changes both increasing and reducing sensitivity.

The Ntan1 gene is expressed in perineural glia and neurons of adult Drosophila.

The Drosophila Ntan1 gene encodes an N-terminal asparagine amidohydrolase that we show is highly conserved throughout evolution. Protein isoforms share more than 72% of similarity with their human counterparts. At the cellular level, this gene regulates the type of glial cell growth in Drosophila larvae by its different expression levels.

Validation of an Optogenetic Approach to the Study of Olfactory Behavior in the T-Maze of Adults.

Optogenetics enables the alteration of neural activity using genetically targeted expression of light activated proteins for studying behavioral circuits in several species including . The main idea behind this approach is to replace the native behavioral stimulus by the light-induced electrical activation of different points of the circuit. Therefore, its effects on subsequent steps of the circuit or on the final behavior can be analyzed.

The Two Main Olfactory Receptor Families in , ORs and IRs: A Comparative Approach.

Most insect species rely on the detection of olfactory cues for critical behaviors for the survival of the species, e.g., finding food, suitable mates and appropriate egg-laying sites.

Novel genetic approaches to behavior in Drosophila.

The study of behavior requires manipulation of the controlling neural circuits. The fruit fly, Drosophila melanogaster, is an ideal model for studying behavior because of its relatively small brain and the numerous sophisticated genetic tools that have been developed for this animal. Relatively recent technical advances allow the manipulation of a small subset of neurons with temporal resolution in flies while they are subject to behavior assays.

Formation and function of intracardiac valve cells in the heart.

harbours a simple tubular heart that ensures haemolymph circulation within the body. The heart is built by a few different cell types, including cardiomyocytes that define the luminal heart channel and ostia cells that constitute openings in the heart wall allowing haemolymph to enter the heart chamber. Regulation of flow directionality within a tube, such as blood flow in arteries or insect haemolymph within the heart lumen, requires a dedicated gate, valve or flap-like structure that prevents backflow of fluids.

Measuring activity in olfactory receptor neurons in Drosophila: Focus on spike amplitude.

Olfactory responses at the receptor level have been thoroughly described in Drosophila melanogaster by electrophysiological methods. Single sensilla recordings (SSRs) measure neuronal activity in intact individuals in response to odors. For sensilla that contain more than one olfactory receptor neuron (ORN), their different spontaneous spike amplitudes can distinguish each signal under resting conditions.

Elements of olfactory reception in adult Drosophila melanogaster.

The olfactory system of Drosophila has become an attractive and simple model to investigate olfaction because it follows the same organizational principles of vertebrates, and the results can be directly applied to other insects with economic and sanitary relevance. Here, we review the structural elements of the Drosophila olfactory reception organs at the level of the cells and molecules involved. This article is intended to reflect the structural basis underlying the functional variability of the detection of an olfactory universe composed of thousands of odors.

Transcriptional basis of the acclimation to high environmental temperature at the olfactory receptor organs of Drosophila melanogaster.

Background: Environmental temperature directly affects the concentrations of chemicals in the gas phase. Therefore, if the olfactory system does not physiologically adapt to environmental conditions, it may provide inadequate information about the distance to or direction of odor sources. Previous reports have shown at the behavioral level that temperature induces changes in olfactory sensitivity in Drosophila melanogaster.

Environmental temperature modulates olfactory reception in Drosophila melanogaster.

Sensory systems, including the olfactory system, are able to adapt to changing environmental conditions. In nature, changes in temperature modify the volatility and concentration of odorants in the air. If the olfactory system does not adapt to these changes, it could relay wrong information about the distance to or direction of odor sources.

Expression analysis of the 3 G-protein subunits, Galpha, Gbeta, and Ggamma, in the olfactory receptor organs of adult Drosophila melanogaster.

In many species, olfactory transduction is triggered by odorant molecules that interact with olfactory receptors coupled to heterotrimeric G-proteins. The role of G-protein-linked transduction in the olfaction of Drosophila is currently under study. Here, we supply a thorough description of the expression in the olfactory receptor organs (antennae and maxillary palps) of all known Drosophila melanogaster genes that encode for G-proteins.

The effect of environmental temperature on olfactory perception in Drosophila melanogaster.

Olfaction provides chemical information to an animal about its environment. When environmental conditions change, individuals should be able to adequately maintain function. Temperature may influence olfaction in a double manner, as it modifies the concentrations of gaseous compounds and affects biological processes.

Quantitative analysis of antennal mosaic generation in Drosophila melanogaster by the MARCM system.

Mosaics have been used in Drosophila to study development and to generate mutant structures when a mutant allele is homozygous lethal. New approaches of directed somatic recombination based on FRT/FLP methods, have increased mosaicism rates but likewise multiple clones in the same individual appeared more frequently. Production of single clones could be essential for developmental studies; however, for cell-autonomous gene function studies only the presence of homozygous cells for the target recessive allele is relevant.

The rdgB gene of Drosophila: a link between vision and olfaction.

otal (ota=olfactory trap abnormal), an X-linked mutation of Drosophila isolated by virtue of abnormal olfactory behavior, is shown to be an allele of rdgB (retinal degeneration B), a gene required for normal visual system physiology. rdgB function is shown to be necessary for olfactory response of both adult files and larvae, which have distinct olfactory systems. Electrophysiological recordings from the adult antenna indicate that rdgB is required for normal response in the peripheral olfactory system: some rdgB mutants show a delayed return to the resting potential following stimulation with ethyl acetate vapor.

High efficiency of a double-screening method on single P-element insertion lines to identify quantitative trait mutants in Drosophila melanogaster.

Enhancer trap P-element insertion has become a common method for generating new mutations in Drosophila melanogaster. When this method is used to isolate mutants for quantitative traits, an appropriate control must be established to define normal and mutant phenotypes. Considering that enhancer-trap lines are generated by crossing several strains, usually with no homogeneous genetic background, no clear control strain can be selected.

The Inositol 1,4,5-triphosphate kinase1 gene affects olfactory reception in Drosophila melanogaster.

The Inositol 1,4,5-triphosphate (IP3) route is one of the two main transduction cascades that mediate olfactory reception in Drosophila melanogaster. The activity of IP3 kinase1 reduces the levels of this substrate by phosphorylation into inositol 1,3,4,5-tetrakiphosphate (IP4). We show here that the gene is expressed in olfactory sensory organs as well as in the rest of the head.

Altered endogenous activation of CREB in the suprachiasmatic nucleus of mice with retinal degeneration.

The effect of cone- and rod-cell loss on the activation of transcription factor CREB (by phosphorylation at Ser133) was examined in the pacemaker of mammals, the suprachiasmatic nucleus (SCN). For this purpose, brain sections of rd/rd and wild-type C3H mice were immunolabeled with a polyclonal antibody that recognises p-CREB, i.e.

The cAMP transduction cascade mediates olfactory reception in Drosophila melanogaster.

Two main second messenger systems depending on IP3 and cAMP have been related to olfaction in vertebrates as well as invertebrates. In Drosophila melanogaster, the availability of mutations affecting one or the other pathway (rdgB and norpA or rut and dnc, respectively) allowed showing of abnormal olfactory behavior phenotypes associated with olfactory transduction in complete living animals. However, because rut and dnc genes showed ubiquitous expression at olfactory receptor organs and some brain locations, the mutant behavior cannot be assigned exclusively to olfactory reception.

Factor analysis of olfactory responses in Drosophila melanogaster enhancer-trap lines as a method for ascertaining common reception components for different odorants.

Olfactory information is transmitted to the brain using combinatorial receptor codes; consequently, a single reception element can be activated by different odorants. Several methods have been applied to describe from a functional point of view those odorants sharing olfactory reception components. A genetic approach in Drosophila melanogaster used correlation between behavioral responses to different odorants for deducing common olfactory pathway-genes.