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Poster Full Abstracts - Neurophysiology and Behavior
Poster board number is above title. The first author is the presenter
302
is completely blocked by a mutation in the
DopR
gene, suggesting that DopR is the main DA receptor involved in sleep/wake regulation. Similar results
were obtained by feeding L-dopa to
DopR
mutants. We are now performing tissue-specific rescue experiments with DopR to determine the specific DopR-
expressing cells that are the downstream targets of the DA wake-promoting neurons. In summary, we have dissected the circuitry underlying the wake-
promoting and locomotion-promoting functions of DA. Current studies include further narrowing down the wake-promoting cells and identifying their
downstream DopR+ targets. Finally, our novel restricted DA Gal4 drivers will be useful tools for those studying the role of DA in behavior.
639C
Using natural variation to investigate
Drosophila
- yeast interactions.
Kelly M. Schiabor. Molecular and Cell Biology, University of California, Berkeley,
Berkeley, CA.
Environments are teeming with microbes that actively contribute to the environment’s chemical makeup. We are interested in understanding the molecular
details of the animal-microbe symbiosis between
Drosophila
and fungi. Specifically, fungi are an essential component of the Drosophila larval diet, and both
adult and larvae Drosophilids have evolved sensory mechanisms to detect and locate fungal species within the environment. Fungi also benefit from this
physical association, as their interaction with
Drosophila
help to disperse these non-motile microbes to fresh, sugary substrates. We hypothesize that small
molecules produced by fungi help to manage this symbiosis by acting as both attractants and behavioral cues for Drosophilids. We have developed and
conducted behavioral assays to determine if
D. melanogaster
show a preference for particular natural
S.cerevisiae
isolates. We have also used gas
chromatography coupled to mass spectroscopy (GC-MS) to characterize differences in the volatile profiles of each
S. cerevisiae
strain.
640A
Structural evidence supporting a conserved role for sleep in synaptic homeostasis.
Daniel B. Bushey, Giulio Tononi, Chiara Cirelli. Dept Psychiatry,
Univ Wisconsin, Madison, Madison, WI.
Sleep is a conserved behavior among divergent metazoans. Although conserved, the functions being performed during sleep remain contested. Evidence in
mammals indicates that sleep is necessary for synaptic homeostasis. During wake, electrophysiological, molecular, and structural studies show that there is a
net increase in synaptic strength in many brain regions that is balanced by a net synaptic downscaling during sleep. Previous studies in
Drosophila
show that
pre and post-synaptic proteins accumulate during wake as compared to sleep in several regions of the fly brain, consistent with the results in mammals.
Recently, we sought to rigorously test the effect that wake and sleep have on the structure of three different neuronal types: small LN
v
s (s-LN
v
s), mushroom
bodies gamma neurons, and visual system interneurons. These circuits are necessary for arousal and circadian rhythm, olfactory learning and memory, and
flight orientation, respectively. Individual neurons expressing unique epitopes that localized either pre or post-synaptically were compared in fixed brains
harvested from sleeping, awake, or sleep deprived (SD) flies. During wake and SD, synaptotagmin-eGFP expression accumulated in larger volumes at pre-
synaptic terminals of the s-LN
v
s and gamma neurons as compared to sleep. Since synaptic volume correlates with synaptic strength, the results are consistent
with increased global synaptic potentiation during wake as compared to sleep. Post-synaptically, visual interneurons had more complex dendritic branches
and more spines in flies that remained awake in an enriched environment compared to flies allowed to sleep or kept awake in small tubes where flight was
not possible. Structural complexity (branch points and spine number) decreased with the time spent asleep. Together, these structural results suggest that
synaptic downscaling occurs during sleep in
Drosophila
. Future studies with calcium imaging will determine whether functional measures of synaptic
strength also change with sleep and wake in flies.
641B
Virtual Fly Brain.
Marta Costa
1
, David Osumi-Sutherland
1
, Simon Reeve
1
, Nestor Milyaev
2
, Cahir O'Kane
1
, J. Douglas Armstrong
2
. 1) Department of
Genetics, University of Cambridge, Cambridge, United Kingdom; 2) University of Edinburgh, School of Informatics, Institute for Adaptive and Neural
Computation, Edinburgh, United Kingdom.
Navigating the Drosophila neurobiology literature and related databases is challenging. For example, it can be a daunting task to find details of the
connectivity between two brain regions, the properties of the neurons involved, and the genes and GAL4 drivers that they express. This problem is rapidly
growing worse as yet larger datasets are produced. One way to tie neuroanatomical data together is in an atlas. Google Earth, with its ability to rotate, zoom,
overlay data and link any feature to additional information is an obvious template. Inspired by this approach, we have developed the Virtual Fly Brain
(VFB), a web-based tool that allows users to browse a 3D confocal stack of a
Drosophila
brain at any angle and various scales. For any brain region down to
the level of individual glomeruli and layers, users can run point-and-click queries for neuron classes based on innervation patterns, for alleles based on
phenotype and for markers and GAL4 drivers based on expression. Subdivision of the brain on VFB is defined using names, boundaries and textual
definitions agreed by the BrainName project [Ito
et al
., in preparation]. Annotations are stored in the FlyBase
Drosophila
anatomy ontology, which also
stores detailed information from the literature about neuron classes, including their lineage, innervation patterns and neurotransmitters. This information can
be searched on VFB via simple template-based queries for neuron classes. Phenotype and expression data is pulled directly from FlyBase, who use this
ontology extensively in their curation. We are currently extending the data sets annotated with our ontology to other neuroanatomical resources. We are also
incorporating alignment tools that allow users to register their stacks to our painted atlas stack and to annotate them using our ontology. With this approach,
we aim to make VFB a hub for querying across multiple neuroanatomical resources and integrating them with genomic and literature resources.
642C
Walking parameters in adult wild type and sensory impaired
Drosophila melanogaster
.
César S. Mendes
1
, Imre Bartos
2
, Turgay Akay
1
, Szabolcs
Márka
2
, Richard S. Mann
1
. 1) Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY; 2) Department of Physics,
Columbia University, New York, NY.
Coordinated walking in vertebrates and multi-legged invertebrates such as the fruit fly
Drosophila melanogaster
requires a complex neural network. This
network is comprised of motor neurons, Central Pattern Generators (CPG’s) - a premotor network of interneurons - and sensory neurons. CPGs produce
rhythmic outbursts, without input from the central brain that target leg motor neurons. Sensory neurons constantly report the position and load of each of the
leg segments and the terrain conditions. This allows precise coordination, stability and a permanent adaptation of the behavior to the environment. A central
question for neuroscientists is the identification of the circuits and cellular mechanisms that govern walking behavior. The fruit fly is an attractive model to