My name is Priyanka Thirumurti. I work at the University at Buffalo at the Jacobs
School of Medicine and Biomedical Sciences. I'm a masters student in the neuroscience department
and my project is on behavioral analysis of neurodegenerative and neuroprotective effects
of two different mutations in the animal model drosophila melanogaster. The levee mutation is
responsible for neurodegenerative effects and the suppressor of the levee mutation
is responsible for neuroprotective effects.
Neurodegeneration is neuronal cell death induced by molecular events involving protein products
and pathways within and between neurons involving protein aggregation that can lead to production of
neurofibrillary tangles as such or other protein related compounds. In the fruit fly brain,
the neuronal cell death is expressed in different regions of the optical lobes
of the fruit fly brain. Specifically,
my research focuses on two mutations in the fruit fly, one of which causes neurodegeneration
as I specified previously, levy, and the other which protects it from occurring,
the suppressor of levy. I conducted different behavioral assays to understand
the effects and the extent and the characteristics of the mutations.
I analyze fly behavior in relation to these types of effects in these two mutations by means of
several different assays that differ in relative environmental sensitivity including space,
temperature, and nutrient exposure. For example the locomotor assay utilizes a
plastic chamber with a small circular opening at the top where one fly at a time is aspirated
into the chamber and a metal spatula is used to nudge the fly ten times to see how many times
out of ten the fly will either fly, walk, jump, or display no movement. In my experiments, 100
flies for five different strains were used for 500 different flies and 5 000 different data points.
In the climbing assay, which is also referred to as a bang sensitivity assay, because the
vial with the flies in them is tapped slightly on the table top to induce climbing movement.
A camera records how many flies are above the 8 centimeter line of each file every 10 seconds.
In my experiments, I tested 250 flies and repeated each set of 10 experiments with 25 flies each
recording data every 10 seconds for two minutes, three times per experiment for a
total of 360 data points. In the life span assay, I studied how long it took each genotype to die.
Transferring.
The flies exposed to fly food every two days and recording the number of dead flies every 24 hours.
In the temperature sensitive paralysis assay, a camera recorded vials with 10 flies of each
genotype placed in racks submerged under a 38 degree celsius water bath
in a tank with a thermometer to indicate changes in temperature as temperature rose in the water
tank. While it was being heated by switching the knob to calibrate the temperature setting.
A total of five experiments were completed with 50 flies per experiment and
five paralysis curves plotted per experiment for each genotype. A paralysis curve shows how
long it takes for a specific mutant or controlled phenotype to paralyze
and takes a shape of half of a parabola with varying widths on
the basis of neurodegenerative or neuroprotective effects.
These different behavioral experiments showed high levels of statistical significance in
demonstrating the neurodegenerative and neuroprotective effects of the mutations,
especially with the locomotor assays and the temperature sensitive paralysis.
Temperature sensitive paralysis assays with a p-value of less than
0.0001. I hope my research can be extended into the field of therapeutic interventions
of related mitochondrial neurodegenerative disorders by recognizing that these mutations,
the levy and the suppressor of levy, which were identified in the context of mitochondrial
encephalopathies induce and suppress neurodegeneration respectively.