The OA1R receptor is required in peripheral neurons to interpret environmental information
1
1,2
Edmond Brewer, Jonathan Andrews , and Sarah J Certel
Center for Structural and Functional Neuroscience1, Division of Biological Sciences2, University of Montana Missoula, MT
2- Methods
1- How is behavior wired into the brain?
In many species, chemical signals from the environment
trigger a variety of possible behavioral responses by an
organism including feeding, aggression, and courtship. How
neurons located at the periphery receive these signals and
mediate the strength of this information before sending it
forward to the brain remains unclear. The neurotransmitter
octopamine (OA, the insect equivalent of norepinephrine)
has been shown by experiments from our lab and others to
be required to promote male aggression (A,B,C). After OA is
released into the extracellular space, it must bind to its
receptors to elicit a response.
Mapping the Circuitry for Drosophila Male
Aggression
(A)
We are using the UAS/Gal4 system, which comprises of Gal4, a transcriptional activator that binds
to UAS, which is an enhancer, in order to increase transcription (A). We are identifying neurons in
the periphery that respond to water and sugar. I am removing the legs and mouth parts of males that
express a fluorescent marker separately12*
in these different neuron3 categories as well as
3 expressing a
fluorescent reporter for the OAβ1R receptor (B,C).
1 University of Montana, Center for Structural and Functional Neuroscience Summer
(A)
Undergraduate Research
Fellowship (SURF), Missoula,
MT
(B)
(C)
2Middlebury College, Middlebury, VT
3University of Montana, Center for Structural and Functional Neuroscience, Missoula, MT
octopamine
Walker, AM
(B)
To understand how signals from the environment
are received and interpreted to generate male
aggression and courtship, I am identifying and
assigning behavioral roles to neurons that express
the Drosophila octopamine receptor, OAβ1R.
(C)
12*
3
3
Walker,
AM
, Bailey, JA , Certel, SJ
Pickpocket28
(ppk28)
is
a
gene
that
1 University of Montana, Center for Structural and Functional Neuroscience Summer
codes for an ion channel protein that
Undergraduate Research Fellowship (SURF), Missoula, MT
detects the presence of water.2Middlebury
The
College, Middlebury, VT
green
representsofthe
OAβ1R
3University
Montana,
Center for Structural and Functional Neuroscience, Missoula, MT
neurons and the red represents the
ppk28 neurons.
Acknowledgements:
OAβ1R neurons in the legs
and proboscis expressing
GFP
UAS-Gal4 system that produces GFP
in neurons of interest.
OAβ1R neurons in the brain
expressing GFP
Mapping the Circuitry for Drosophila
Male
MT
Co-localization
between
(A)
2Middlebury
University of Montana, Center for Structural and Functional Neuroscience Summer
Undergraduate Research Fellowship (SURF), Missoula, MT
2Middlebury College, Middlebury, VT
3University of Montana, Center for Structural and Functional Neuroscience, Missoula, MT
1
Figures A-C are images of the
proboscis, and Figures D-F
are of the last segment of the
leg. The green represents the
OAβ1R neurons and the red
represents the Gr64e neurons.
Arrows point to areas of high
co-localization.
6- Is this territory worth fighting for? Detecting sugar content
5- Is this territory worth fighting for? Detecting sugar content
3
Walker, AM12*, Bailey, SJ
neuron.
(F)
Male
GFP
Co-localization
between
Mapping the Circuitry for Drosophila
Male
(A)
OA1R and Gr64e,
Aggression which is a sugar-sensing
(D)
, Bailey, JA , Certel, SJ
Mapping
the Circuitry
Co-localization
between
OA1R and for Drosophila
ppk28
Aggression
OAβ1R
4- Is this territory worth fighting for? Detecting sugar content
(B)
3- Is this territory worth fighting for? Communicating water sensitivity
College,
OA1R and Gr64f,
which is a sugar-sensing
neuron.
Figures A-C are images of the
proboscis, and Figures D-F are
of the last segment of the leg.
The green represents the
OAβ1R neurons and the red
represents the Gr64f neurons.
Arrows point to areas of high
co-localization.
(C)
(B)
What will be gained
from this territory?
(D)
High
sugar
content
(E)
(C)
(F)
(E)
(A)
Low
sugar
content
Mapping the Circuitry for Drosophila Male
Aggression
(B)
(C)
Walker, AM12*, Bailey, JA3, Certel, SJ3
1
University of Montana, Center for Structural and Functional Neuroscience Summer
Undergraduate Research Fellowship (SURF), Missoula, MT
2Middlebury College, Middlebury, VT
Co-localization between OA1R and
3University of Montana, Center for Structural Neuroscience, Missoula, MT
Gr64b, which is a sugar-sensing neuron.
(D)
(E)
(F)
Figures A-C are images of the
proboscis, and Figures D-F are of the
last segment of the leg. The green
represents the OAβ1R neurons and the
red represents the Gr64b neurons.
Arrows point to areas of high colocalization.
7- Conclusions and Looking to the Future
• Oa1R-expressing neurons may be involved in the detection of water, and possibly the regulation
of water intake.
• Oa1R-expressing neurons may be involved in the detection of sugar and regulating sugar intake.
• These results are a launching point to learn how any organism modulates their behavior based on
the interpretation of outside signals.
Future Experiments
•Now that specific neurons have been identified to possibly utilize octopamine, we can set up
aggression assays in which the water or sugar content of the substrate has been altered. Quantifying
the aggression that results will allow us to determine the involvement of octopamine in both the
ppk28 and the Gr64 neuronal pathways.