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Poster Full Abstracts - Neurophysiology and Behavior
Poster board number is above title. The first author is the presenter
304
Technology, Pasadena, CA; 3) Max Planck Institute for Brain Research, Frankfurt, Germany.
The
Drosophila
mating ritual is an extremely robust example of an auditory social interaction. Each male of the roughly 2000
Drosophila
species sings a
unique song using wing vibration and females typically ‘listen’ to many minutes of song before accepting a mate. Despite decades of research on courtship
songs and behavior in
Drosophila
, central auditory responses have remained uncharacterized. We report on intracellular recordings from central neurons that
innervate the
Drosophila
AMMC (antennal mechanosensory and motor center), the first relay for auditory information in the fly brain. These neurons
produce graded-potential (non-spiking) responses to sound; we compare recordings from AMMC neurons to extracellular recordings of the receptor neuron
population (Johnston’s Organ neurons or JONs). We discover that while steady-state response profiles for tonal and broadband stimuli are significantly
transformed between the JON population in the antenna and AMMC neurons in the brain, transient responses to pulses present in natural stimuli (courtship
song) are not. For pulse stimuli in particular, AMMC neurons simply low-pass filter the receptor population response, thus preserving temporal features
(such as the spacing of song pulses) for analysis by postsynaptic neurons. We also compare responses in two closely related
Drosophila
species,
D.
melanogaster
and
D. simulans
, and find that pulse song responses are largely similar, despite differences in the spectral content of their songs. Our
recordings inform how downstream circuits may read out behaviorally-relevant information from central neurons in the AMMC.
647B
Screening of Central Pain Circuits.
Wijeong Jang, Sunwoo Kim, Changsoo Kim. Sch Biological Sci, Chonnam National Univ, Gwangju-Si, South Korea.
In Drosophila, multi-dendritic (MD) neurons represent the peripheral nociceptive neural circuits sending nociceptive signals to the brain. Little is known
about the central nociceptive neural circuits that process these nociceptive signals from peripheral noxious stimuli. Here, we describe both the screening and
identification of the potential central nociceptive neural circuits that mediate pain processing in the brain. Drosophila does not carry capsaicin receptors, so
capsaicin can selectively activate neural circuits that do express capsaicin receptors. The mammalian vanilloid receptor TRP channel (TRPV1) is a capsaicin
receptor that responds to noxious heat and capsaicin. We crossed UAS-hTRPV1 flies with “brain-Gal4” lines known to express Gal4 in the subsets of the
brain. Progenies from the cross were then reared with capsaicin-laced food to stimulate neural circuits when they were eating. The logic behind this
experiment was that flies experiencing nociception through stimulation of their central nociceptive neural circuits will avoid ingestion of food and
subsequently starve to death. From the screening, we identified several lines that exhibited such starvation- induced death. We focused on one line of the
“brain-Gal4” whose expression was limited in the subset of the brain and thus could represent the central nociceptive neural circuits.
648C
Analgesic Drugs Relive Pain in Drosophila.
Sunwoo Kim, Myungsuk Oh, Eunhee Cho, Wijeong Chang, Changsoo Kim. Chonnam National University,
Gwangju, South Korea.
Analgesic drugs relieve pain in vertebrates. We were interested in knowing whether analgesic drugs also reduce nociception in Drosophila. We generated
transgenic flies that expressed the human capsaicin receptor (or TRPV1) in nociceptive multidendritic (MD) neurons, using the Gal4UAS binary expression
system to induce nocicpetive neural circuits by capsaicin. We found that capsaicin-induced nociceptive behaviour appeared in the transgenic larva and adult
flies. Of note, we found that the flies avoided ingestion of food if the food contained capsaicin, leading to death by starvation. This death rate increased as
temperature, capsaicin concentration, and the dose of the UAS-hTRPV1 increased, suggesting that the death rate represented the level of nociception that the
flies experienced when they ingested capsaicin-laced food. We also found that when analgesic drugs were included in the capsaicin food, reduced death rate,
suggesting that analgesic drugs are effective in relieving nocicpeiton in Drosophila. We propose that this simple assay system can be useful for assessing
potential compounds for in vivo efficacy for pain reduction.
649A
Drosophila exhibit active avoidance behavior in response to a predator.
Claire J. Manson-Bishop
1,2
, Gregg W. Roman
1,2
. 1) Biology and Biochemistry,
University of Houston, Houston, TX; 2) Biology of Behavior Institute, University of Houston, Houston, TX.
Understanding the response of
Drosophila melanogaster
to predators is both relevant ethologically and important for the establishment of an anxiety-like
behavioral model within this organism. Such a model will enable the dissection of the molecules and neurocircuits involved in the modulation of anxiety.
The behavioral response of Drosophila to predators has not been previously characterized; it is the goal of these experiments to characterize how the
presence of predators changes the behaviors of Drosophila and to elucidate the sensory mechanisms responsible for these responses to a predator. In order to
address this fundamental question, we studied Drosophila within the circular open field paradigm. For these experiments, we used two predators: the
Pantropical jumping spider (
Plexippus paykulli
) and the Carolina mantid (
Stagmomantis carolina
). Both predators are capable of capturing and preying upon
Drosophila in large arenas. We show that Drosophila avoid the predators that are caged within the center of a circular open-field arena. Furthermore, in the
presence of a caged predator Drosophila also exhibit a preference for a recessed alcove. This preference may represent a shelter-seeking response that is
enhanced by the proximal danger of the predator. To begin to assess the sensory modalities required for this active avoidance behavior, we investigated the
response of blind
norpA
7
flies and broadly anosmic
or83b
2
flies, independently, to a caged Pantropical jumping spider. Both
norpA
7
and
or83b
2
flies
demonstrate avoidance of the predator, and a preference for the recessed alcove. The significant responses of both these genotypes to these predators may
suggest that Drosophila uses redundant sensory modalities to detect and avoid predators.
650B
A functional genomic screen for phototransduction genes in
Tribolium
.
Arun K Sasikala-Appukuttan
1
, Matthew Kulpa
1
, Zahabiya Husain
1
, Magdalena
Jackowska
1
, Bryce Daines
2
, Jason Caravas
1
, Rui Chen
2
, Heinrich Jasper
3
, Markus Friedrich
1,4
. 1) Department of Biological Sciences, Wayne State
University, 5047 Gullen Mall, Detroit, MI 48202, USA; 2) Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor
College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; 3) Department of Biological Sciences, University of Rochester, River Campus
Rochester, New York 14627, USA; 4) Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, 540 East Canfield Avenue,
Detroit, MI 48201, USA.
The visual system of higher Diptera like
Drosophila
is characterized by a complex pattern of differential photoreceptor sensitivities across the retina and
an exceptionally fast photoreceptor response. Previous research in our lab has shown that the latter is associated with the derived duplication and