The 16th Annual
NC State
University
Undergraduate Research Symposium
Biological Sciences:
Zoology, Physiology,
Behavior, Neurobiology
Abstracts
Abstracts are listed in alphabetical order by the last name of the
corresponding author.
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Allmond, Jillian |
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Department(s): |
Zoology |
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Research |
John Godwin/Zoology Gisele Passador-Gurgel/Zoology |
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Title of Presentation: |
Use of cDNA
Microarray Technology to Study Sexual
Differentiation of the Brain in the Bluehead Wrasse |
Sexual differentiation is
often controlled by genetic expression and hormonal regulation. Bluehead wrasses (Thalassoma bifasciatum)
made good models to study sexual differentiation because of their ability to
change sex over relatively short periods of time. When an aggressive terminal phase male is
lost, initial phase males or initial phase females may undergo a role change or
sex change respectively. In order to
gain a better understanding of altered gene expression patterns underlying this
pattern of sexual differentiation, we compared RNAs
from two sexual phenotypes using cDNA microarrays. Experiments included 18 independent
hybridizations comparisons of a TP male with a female. Each comparison experiment included RNA
extractions from each brain (10 TP males and 10 females), RNA amplification and
labeling, and then heterologous hybridizations on the
arrays (heterologous because we are using arrays
constructed from the closely related Astatotilapia buroni).
Following hybridization, the arrays were scanned and the images were
processed using ScanAlyze. Data will be analyzed using two sequential
ANOVA models to rigorously identify differentially expressed genes. The results obtained from this project will
lead to a better understanding of gene expression in the brain and the role
those genes play in the sexual differentiation of the bluehead
wrasse. This project also further
validates the usefulness of heterologous
hybridizations.
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Buerkle, Shawna C. |
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Department(s): |
Zoology |
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Research |
James F. Gilliam/Zoology Brad A. Lamphere/Zoology |
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Title of Presentation: |
Comparing Exploratory
Behavior in Two Contrasting Types of Rivulus hartii Populations |
It is important to study
behavioral syndromes such as the bold-shy continuum in order to more fully
understand the environmental and evolutionary origins and consequences of
personality traits in wild populations, with possible applications to human or
veterinary medicine. In this study we examined the “boldness” of a tropical
killifish, Rivulus hartii,
from two predator regimes, with each regime replicated across two watersheds.
Non-predator Rivulus populations are above waterfalls
and free from strongly predatory fish present below the waterfalls. In the
laboratory we assayed time required for individuals to “peek” from cover, a
test analogous to the “elevated maze” test often used in rodent trials. In
laboratory trials at NCSU, fish from non-predator regions were significantly
more bold than fish from predator regions (repeat measures ANOVA, p<0.001).
Trials on freshly caught, wild populations in
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Bumgardner, Sara A. |
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Department(s): |
CIIT Centers for Health
Research, |
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Research |
David C.
Dorman/Neurobiology, Melanie F.
Struve/Neurobiology, CIIT Centers for Health Research |
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Title of Presentation: |
Semiquantitative Histochemical Analysis
of Olfactory Epithelial Cytochrome Oxidase Activity Following Acute Hydrogen Sulfide
Exposure |
Our laboratory has
previously shown that hydrogen sulfide (H2S)-induced inhibition of cytochrome oxidase may be
associated with olfactory neuronal loss in rats. A positive correlation between
H2S flux to the exposed epithelium and olfactory neuronal loss has also been
demonstrated using an anatomically correct computational fluid dynamics model
of the rat nose. The purpose of this pilot study was to develop enzyme histochemical methods to assess cytochrome
oxidase activity in situ in the nasal epithelium and to
evaluate whether cytochrome oxidase
inhibition is correlated with the location and severity of H2S-induced lesions.
Male CD rats (n=3-4/exposure group) were exposed by nose-only inhalation for 2
hours at inspired concentrations of 0 or 200 ppm H2S,
an exposure level associated with olfactory neuronal loss in rats. Immediately
following the exposure, animals were euthanized by pentobarbital overdose, perfused with paraformaldehyde,
and the nose and brain were removed and placed in sucrose for cryoprotection. Frozen sections of brain (positive control)
and three transverse levels of the nose containing olfactory epithelium were
collected and processed for semiquantitative (densitometric) cytochrome oxidase enzyme histochemistry.
The level of cytochrome oxidase
activity in control nasal epithelium varied depending on location and exceeded
the normal levels seen in some brain regions. Olfactory epithelial cytochrome oxidase activity was
reduced in the dorsal meatus, septum, and certain turbinates of H2S-exposed rats vs. air-exposed controls,
sites that also exhibited olfactory neuronal loss. Ongoing efforts will
complete production of epithelial mapping of cytochrome
oxidase activity in treated and control animals with
subsequent evaluation of site-specific flux to these sites.
|
Castor, Christopher B. Smith,
Debbie L. |
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Department(s): |
Zoology |
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Research |
Robert M. Grossfeld/Zoology |
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Title of Presentation: |
Activation of Optic Nerve Glia by ATP and Glutamate |
Glial cells, the most abundant cells in the central
nervous system, are now recognized as regulating blood flow and functions
previously thought to be performed only by neurons. ATP and glutamate are
important chemical transmitters used by both neurons and glia. However, at high concentrations they are
toxic, contributing to neurodegenerative disorders. We aim to determine the relative
contributions of these two compounds to neuron-glia
signaling and neurotoxicity. We isolated optic nerves from P5-P15 day old
rats, incubated them with a calcium-sensitive dye, and observed glial cell calcium responses by optical imaging. Nerves were treated with either of the
suspected neuro-glio-transmitters with or without
specific blockers of their receptors present. ATP at 10 or 100 mM elicited in optic nerve glia
a robust calcium response that could be partially blocked by 10 mM Suramin,
an ATP receptor antagonist. When 10 mM Suramin was used together
with 10 mM CGS 15943, an
adenosine receptor blocker, the response to ATP was blocked completely. These results suggest that the action of ATP
is mediated via a combination of intact ATP acting on P2 purinergic
receptors and adenosine formed from it acting on P1 purinergic
receptors. Glutamate at 100 mM gave a longer-lasting response than 100 mM ATP. This
excitation was partially blocked by 10 mM Suramin and completely
blocked by a combination of 10 mM Suramin with 10 mM CGS 15943.
However, since this effect was not reversible we are currently
evaluating how these purinergic receptor blockers
affect the response to glutamate.
Published data indicate that responses of optic nerve glia to ATP and glutamate are blocked completely by Suramin, implicating ATP receptors as the sole mediator of
responses to ATP and ATP as an intermediary in the action of glutamate but our
results suggest the need to reconsider that conclusion.
|
Fearn, Kenneth J. |
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Department(s): |
Biomedical Engineering |
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Research |
Wake Forest Institute for Regenerative
Medicine |
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Title of Presentation: |
Complete
Decellularization of SIS for Safer Bladder
Regeneration Techniques |
In current bladder
regeneration techniques, partially decellularized
small intestinal submucosa (SIS) from swine is used as
the structural matrix for artificial bladders and ureters. Although the current use of SIS allows the
artificial organ to function properly, the remaining swine cellular material
within the matrix poses a threat as a possible source of immunoreaction
and rejection of that organ by the body.
Therefore, this study examines the ability of completely decellularized small intestinal submucosa
(dSIS) to sustain cellular life for both in vitro
and in vivo studies. If dSIS shows to be a life supporting material, it will be a
safer alternative for use in artificial organs due to the reduced risk of
immunoreactions. This study has not yet
been conducted because it is hypothesized that growth factors from the
remaining cellular material actually helps promote proliferation and growth
into the matrix. In the study itself,
human Bone Marrow Stromal Cells (hBMSC)
were seeded onto the dSIS in culture medium for both
experiments and allowed to grown within their respective environments (either
in cell incubator or nude mice) up to 28 days.
After histological staining was done on the samples, it was concluded
that the material does in fact allow the hBMSC to
proliferate and penetrate into the matrix.
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Student
Author(s): |
Fedewa Jr., Michael J. |
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Biological Sciences |
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Research |
Anita P. Flick/Biological
Sciences |
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Title of Presentation: |
Anterior Cruciate Ligament Reconstructive Surgery: The Benefits
and Disadvantages of the Three Most Common Procedures |
This research presents the
importance of the Anterior Cruciate Ligament and the
techniques for reconstructive surgery when it is damaged or torn. More
specifically, the research is an analysis of the three most common procedures
used The paper is a result of research from several scholarly sources citing
studies and theoretical data. The data suggests more risk and less reward with
cadaver tendon grafts, and a nearly equal result comparing the hamstring and
patellar tendon grafts.
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Hinkle, Ruth E. Burke, Katherine T. |
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Department(s): |
Zoology |
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Research |
Heather B. Patisaul/Zoology |
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Title of Presentation: |
Phytoestrogens and Anxiogenic Effects
in Male Rats |
Phytoestrogens are estrogen-like compounds found in plants. Because
these compounds are structurally similar to estrogens found in the human body,
they can either block or enhance normal estrogen activity. Estrogen has been
shown to improve mood but it is not known if phytoestrogens
have the same effect. The focus of our experiments was to determine the effects
of the phytoestrogens, equol
and resveratrol, on anxiety in intact Long-Evans male
rats. There are two types of receptors through which estrogen act: Estrogen
receptor beta (ER-β) and estrogen receptor alpha (ER-α). Diarylpropionitrile (DPN), an ER-β agonist, and propylpyrazole-triol (PPT), an ER-α agonist, were used
to determine the receptor subtype responsible for mediation of anxiety. Adult
rats were first injected and tested at low doses of equol,
resveratrol,oil (control), DPN, and PPT. Several
weeks later, the same substances were administered and tested at higher doses.
To test developmental effects, DPN, PPT, and equol
were injected post natal days 0-5 and later tested days 56-61. DPN appeared to
increase anxiety in both adult and juvenile rats. Males that were treated neonatally showed anxiogenic
behavior when tested as juveniles, suggesting that DPN has a developmental
effect on the brain. Equol appeared to have anxiogenic effects in both neonates and adults. When
administered at low doses, equol showed a tendency to
increase anxiety. When given at higher doses, the anxiogenic
behavior was significantly higher, indicating a dose-dependent effect. Resveratrol had significant anxiogenic
effects when administered at higher doses.
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Iyengar, Mangala S. Jacquet, Benoit |
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Department(s): |
Molecular Biomedical
Sciences, |
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Research |
Troy Ghashghaei/
Molecular Biomedical Sciences, |
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Title of Presentation: |
Transcription Factor FoxJ1 may Specify a Subset of Astrocytes as Stem Cells in the Adult Brain |
A subset of astrocytes in the
central nervous system (CNS) retains stem cell-like properties long into adult
mammalian development. To utilize endogenous stem cells in cell-based therapies
for neurodegenerative disorders, a comprehensive molecular characterization of
these cells is necessary. We have discovered that a set of astrocytes
in distinct CNS regions express a Forkhead
transcription factor, FoxJ1. In transgenic mice that express enhanced green
fluorescent protein (EGFP) under the FoxJ1 promoter, FoxJ1 is expressed in the
adult neurogenic region of the anterior subventricular zone (SVZ). Nearly all FoxJ1+ cells
differentiate into the astrocytes and ependymal cells that form the adult stem cell niche. We
present unprecedented evidence that astrocytes are
divided into two molecularly distinct subsets based on the presence of FoxJ1+
and FoxJ1- astrocytes throughout the brain. This
division is supported by the fact that the differentiation of FoxJ1+ cells into
astrocytes appears to be delayed relative to
maturation of FoxJ1- astrocytes during early
postnatal life. We also present evidence that many adult astrocytes
that express FoxJ1 exhibit a mitotic profile in the SVZ. This supports our
working hypothesis that the subset of FoxJ1+ astrocytes
may be the adult stem cells. This study forms a basis for assessing the role of
FoxJ1 and FoxJ1 expressing cells in the development and maintenance of the
adult stem cell niche.
|
Rankin, Susanna K. |
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Department(s): |
Zoology |
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Research |
John Godwin/Zoology James Gilliam/Zoology |
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Title of Presentation: |
Domestication and Genetic
Contributions to Anxiety-related Behaviors in Danio rerio (Zebrafish) |
In recent years the zebrafish (Danio rerio) has become an important biomedical research
model. Because of this, we are using this species to assess genetic and
environmental contributions to the display of anxiety-related behaviors and
differences between wild and domestic stocks. Research in this model organism
could lead to a better understanding of mood disorders in humans and advances
in aquaculture where stress-responsiveness impacts growth and disease
resistance. We have tested lab-reared zebrafish
derived from two stocks (a wild stock from
|
Rouf, Cynthia |
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Department(s): |
Entomology |
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Research |
Christina Grozinger/Entomology Yongliang Fan/Entomology Freddie-Jean
Richard/Entomology |
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Title of Presentation: |
Effect of Queen Mandibular Pheromone on Honey Bee Nestmate
Recognition |
Nestmate recognition is a type of learning and memory in
honey bees (Apis mellifera)
that workers use to distinguish closely related conspecifics
from both heterospecific individuals and unrelated conspecific intruders, towards which aggression is then
directed. Previous nestmate recognition studies
indicate a strong genetic basis for nestmate
recognition, which likely combines with previously discovered environmental
olfactory cues to help workers recognize nestmates.
Queen mandibular pheromone, which regulates many
aspects of worker behavior and physiology, seems to improve individual workers’
learning and memory, which are necessary for nestmate
recognition. In colony-level studies, however, QMP-treated colonies showed less
aggression than colonies without QMP. Because aggression against nonnestmates follows proper recognition of nestmates versus nonnestmates, we
tested the effects of QMP on nestmate recognition at
the level of the individual worker. After a week of pheromone treatment, we
compared QMP treated workers' responses towards both nestmates
and nonnestmates to the responses of a group of
workers without QMP. Our results--which showed a markedly higher mortality rate
of nonnestmate intruders in QMP
treated cages versus control cages-- support that QMP plays an important role
in enhancing workers' genetically-based abilities to recognize nestmates. QMP, thus, shows profound effects on olfactory
discrimination and aggression towards recognized nonnestmates.
The molecular and neurological basis behind the effect of QMP on these
behaviors is a topic for further research.
|
Selgrade, Brian |
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Department(s): |
Biomedical Engineering |
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Research |
Peter L. Mente/Biomedical Engineering |
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Title of Presentation: |
Surface Cracking of
Porcine Articular Cartilage Resulting from Shear
and |
Osteoarthritis, a common and
painful joint disease, is often caused by injury to articular
cartilage during a forceful impact to the joint. While impact injuries in vivo
usually involve significant shear forces, most previous studies have used only
normal impacts to simulate injuries to articular
cartilage. In this study, normal impactions were conducted on porcine patellar
cartilage to determine the best strain rate at which to carry out further
tests. Next, we impacted more specimens using simultaneous shear and normal
loads at a .05mm/sec strain rate. We find that strain rate has no significant
effect on cracking in normal impactions, while maximum normal load
significantly affects both shear load and net crack length in shear impactions.
Cracking in cartilage is reportedly related to collagen damage, and more
studies are currently being conducted to relate the amount of collagen damage
at different depths to surface cracking.
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Williams, Mary Anne F. Kovary, Kaitlin King, Eric Pegg, Catherine |
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Department(s): |
Food Science |
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Research |
Jonathan Allen/Food
Science |
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Title of Presentation: |
Exercise Motivation |
In a study to investigate
the motivation behind exercise in athletes, active people, and inactive people
(allowing the individual to use their own discretion in labeling themselves
with no formal definition provided), we used a survey to outline the exercise
habits of individuals on campus. The surveys were filled out almost exclusively
by college-aged students. Some of the significant trends we observed were that
athletes were almost the only individuals to ever workout for more than 2 hours
at a time, and they preferred to workout in groups, while inactive people
preferred to workout (when they did) alone, with active people divided between
preferring groups, a partner, and solitude. Almost all individuals claimed to
be self-motivated, liked to listen to music during exercise, and disliked
reading during their workout. Athletes typically workout for
competitive reasons, active people to enhance or maintain physical appearance,
and inactive people to fit into their clothes. One particularly
interesting finding was that almost all athletes had a supportive friend who
was either involved in their workout or was interested and encouraging of
milestones passed. None of the inactive people had such a friend, and as for
the active people, the less active they were (based on how often they workout),
the less likely they were to have a supportive friend. In conclusion, the more
active an individual is (by their own definition), the more likely they are to
have and enjoy social support in their exercise habits.
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Williams, Valerie N. |
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Department(s): |
Zoology |
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Research |
Craig V. Sullivan/Zoology |
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Title of Presentation: |
Characterization of the
Multiple Vitellogenin System of Xenotoca eiseni, a Viviparous Goodied Fish |
This study explored oocyte growth in the viviparous teleost
fish, Xenotoca eisen. It was
unknown whether highly matrotrophic fishes, whose
young develop fully inside the ovary while receiving maternal nutrients via a
pseudo-placenta, utilize the same forms of egg yolk precursors (vitellogenins [Vgs] A, B, and C)
found in oviparous species. Adult males were injected with estrogen to induce vitellogenesis and their blood plasma was subjected to
sodium dodecylsulphate-polyacrylamide gel
electrophoresis and Western blotting using an antiserum to white perch (Morone americana) Vgs (A+B). A single estrogen-induced, immunoreactive
band corresponding to a mass similar to other teleost
A/B-type Vgs (~180 kDa) was
apparent on the Western blot. Partial complementary DNAs
(cDNAs) encoding Vgs were
cloned from hepatic RNA isolated from estrogenized
male Xenotoca
by polymerase chain reaction (PCR) using degenerate primers designed de novo for VgC
and those employed for VgA and VgB
in our prior studies. Resulting sequences were compared to Vg sequences in the
databases at the
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