1. SAMPLE REPORT FORMAT
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B.
A*STAR Singapore International Pre-Graduate Award (SIPGA)
Research Attachment Experience in Singapore
Project title: Serotonin neurons in emotional behaviour
Introduction
I am an MD student at Charles University in Prague, and have undertaken
research attachments in the UK, Switzerland, Taiwan, and France. My
work with Drosophila has been critical in my development as a scientist,
and in the future I am hoping to integrate research with clinical practice in
neurology. At IMBC I have been involved with two projects working with
Drosophila: The first consisted of initial experiments investigating whether
serotonergic neurons trigger the proboscis extension reflex (PER). The
second demonstrated the necessity of serotonergic neurons in inducing a
state of tranquility, using an assay called the Optogenetic Self-
administration Response (OSAR) that allowed flies to self-activate
serotonergic neurons. In these projects, serontergic cells were targeted
using the Gal4-UAS system (Tryptophan hydroxylase, Trh-Gal4) and
responders csChrimson to activate and GtACR1 to inhibit.
Research Work and Experience in A*STAR
Proboscis Extension Response (PER)
Serotonin has a major role in feeding and satiation. To test if serotonin
levels activate PER, Flies were tested in two different states of satiation:
Fed, and 24 hour starved. Flies were anaesthetized with CO2 and then
glued to a coverslip, facing ventrally upwards. PER was captured on
digital film.
Figure A: Percentage of flies showing PER in two states of satiation. Experimental flies Trh-Gal4>csChrimson.and control flies w1118;csChrimson
and Trh-Gal4; w1118 combined.
Figure B: Proboscis.. With activation of serotonergic neurons in red light, experimental flies show partial extension (Right panel)
Light activation of serotonergic neurons appears to trigger the PER reflex,
regardless of satiation state. Flies carrying Trh-Gal4 driving red light
responsive csChrimson showed PER with exposure to red light. In a fed
state, 5 of 8 flies showed protraction. Serotonin therefore appears to
trigger the PER reflex.
Optogenetic Self-administration Response (OSAR)
Serotonin has a central role in the pathophysiology of addiction disorders.
OSAR models the self-administration aspect of addictive behaviour as it
Name: Helen Whitley Email: Helen.whitley@gmail.com
Nationality: British RI/Consortium: IMBC
University: Charles University Period of Attachment: 3 Months
fed 24h starved
n experimental
flies 8 6
% PER 62.5% 33%
n control flies 7 6
% PER 0% 0%

2. SAMPLE REPORT FORMAT
presents flies with the choice of seeking or avoiding the light. To show the
necessity of serotonergic neurons in reducing aversive behaviors, a novel
anion channel (GtACR1) was used to inhibit neurons by preventing the
cell from forming an action potential. GtACR1 is activated by green light.
Flies carrying Trh-Gal4 driving green light responsive GtACR1 were
therefore predicted to avoid green light in the OSAR arena. Flies were
tested at three different light intensities: Quarter, half, and full.
Figure A: Flies carrying Trh-Gal4 driving red light responsive csChrimson in all serotonergic neurons had an increased preference for red light.
Preference index (PI) increases with light intensity.
Figure B: Flies expressing green light responsive GtACR1 in all serotonergic neurons show modest avoidance of green light. For highest green light
intensity the reduction in delta PI was 16% [-0.16, 95CI 0.01, -0.31]
The light preference shown by Trh-Gal4 flies with csChrimson responder
indicates that flies choose serotonergic neuron activation. This suggests
that the neurons activated behave as an endogenous tranquillizer.
Conversely, Trh-Gal4 flies with GtACR1 responder show a modest
avoidance of green light (-16% in full intensity). This suggests that
GtACR1 is indeed inhibiting serotonergic neurons, and serotonin may
therefore be necessary for a tranquil state.
General Experience in Singapore
High living costs are compensated for by the quality of life and well
developed infrastructure. Public amenities are very efficient, safe, and
clean. The spectrum of cultures living in close proximity formed a peaceful
and tolerant community, which was easy to integrate into
Future Plans
My interest in neuroscience lends itself well to neurology, a field with many
opportunities for clinical research. I am aiming to find ways to incorporate
research into clinical work in neurology. Serotonin deregulation is a core
aspect of neurological diseases including chronic migraine, epilepsy,
Parkinson’s, Alzheimer’s, and dementia. Drosophila provide a well
established framework for investigating serotonin pathways. Elucidating
the neuronal network underlying the serotonergic pathway in a lower
species can reveal highly conserved mechanisms for serotonin regulation.