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anatomical outcomes and by promoting cell survival. However, ac-
cording to recent reports, the EP1 receptor roles are complex and the
neuroprotective effects of its inhibition might be compensated or
overpowered by adverse effects or toxicity in models of brain trauma
and intracerebral hemorrhage. Consequently, the goal of this study
was to investigate the effect of a selective EP1 receptor antagonist,
SC-51089, on delayed neurodegeneration induced by traumatic brain
injury (TBI) using a controlled-cortical impact (CCI) model with two
different injury magnitudes in mice. The data demonstrate that neu-
rological deficit scores at 24 and 48 h after CCI rose with increasing
injury magnitude. Repeated post-treatment with 20
l
g/kg of SC-51089
has no significant effects on neurological deficit scores as compared to
vehicle groups with either magnitude. Of interest, ten days after the
severe CCI in the SC-51089 treatment group, the delayed hippo-
campal tissue loss was greater as compared to controls. The data, in
combination with published reports, suggest that the EP1 inhibition
worsened delayed degenerative processes in the hippocampus at sub-
acute time points after TBI, and that this effect is more profound with
increased trauma severity, likely due to the increased contribution of
hemorrhagic injury.
Keywords: controlled-cortical impact, Prostaglandin E2, In-
flammation, G-protein coupled receptors
B2-06
REGIONAL EXPRESSION OF WILD-TYPE ALPHA-
SYNUCLEIN AFTER TRAUMATIC BRAIN INJURY IN RATS
C. Edward Dixon
1,2
, Hong Q. Yan
1,2
, Shaun Carlson
1,2
, Youming
Li
1,2
, Jeremy Henchir
1,2
, Xiecheng Ma
1,2
1
UPitt, Neurosurgery, Pittsburgh, USA
2
VAPHS, GRECC, Pittsburgh, USA
Introduction:
Synucleins (Syn), a family of synaptic proteins, in-
cludes alpha-synuclein (
a
-Syn), which plays a pivotal role in neuro-
degenerative diseases. The native function of
a
-synuclein is not
completely understood, but is thought to involve regulation of syn-
aptic vesicle trafficking. While the pathological forms of
a
-syn are
considered to be the primary targets of TBI-associated neurodegen-
eration, disruption of the native function of
a
-Syn may contribute to
pathology by diminishing synaptic function. The goal of the project
was to examine the regional effects of TBI produced on wild-type
a
-Syn expression at 6 hours to 8 weeks post injury.
Methods:
Male Sprague-Dawley rats were anesthetized and sur-
gically prepared for controlled cortical impact (CCI) injury (4 m/sec,
2.6 mm) or sham surgery. Semi-quantitative Western blot measure-
ments of the hippocampal, frontal cortex and striatal tissues from rats
sacrificed at 6 h, 1 d, 1 wk, 2 wks, 4 wks and 8 wks after injury or sham
operation (N
=
6 per group).
Results:
The expression of
a
-Syn was decreased ipsilaterally from
6 hrs to 8 wks in the hippocampus, at 1 wk and 2 wks in the frontal
cortex, and bilaterally at 6 hrs only in the striatum (P
<
0.05). Double-
label immunofluorescent staining sacrificed at 1 wk after TBI or sham
for
a
-Syn, neuron marker NeuN and astrocytes marker glial fibrillary
acidic protein (GFAP) confirmed the Western blot findings. There is
no overt change of NeuN immunostaining in regions of
a
-Syn loss.
The increased expression of GFAP represents concomitant astro-
gliosis.
Conclusion:
This study suggests that the decreased wild-type
a
-Syn expression in different brain regions after TBI may represent
the complicity of
a
-Syn functions in the brain regions. Additional
work is required to determine if this represents a shift toward more
cytotoxic forms of
a
-Syn or a reorganization of synaptic vesicle
trafficking after TBI.
Acknowledgments
VA I01RX001127, The Pittsburgh Foundation, NIH-NS091062,
NIH-NS40125, NIH-NS060672.
Keywords: traumatic brain injury, alpha-synuclein, Western blot,
immunofluorescence
B2-07
NEUROPROTECTIVE EFFECT OF METHYLENE BLUE IN
MODERATE TRAUMATIC BRAIN INJURY
Lora Watts
1–3
, Justin Long
1
, Qiang Shen
1
, Timothy Duong
1
1
University of Texas Health Science Center San Antonio, Research
Imaging Institute, San Antonio, USA
2
University of Texas Health Science Center at San Antonio, Depart-
ment of Cellular and Structural Biology, San Antonio, USA
3
University of Texas Health Science Center at San Antonio, Depart-
ment of Neurology, San Antonio, USA
Methylene blue (MB) has unique energy-enhancing and antioxidant
properties and has positive acute therapeutic effects following TBI in rats.
We hypothesized that MB treatment would reduce lesion volume and
improve functional recovery in a rat TBI model. Anesthetized rats un-
derwent a 6mm craniotomy over the left primary motor/somatosensory
cortex region to expose the dura matter and were impacted using a
pneumatic cortical impactor (impact velocity 5.0m/s, 250
l
s dwell time,
and 1mm depth) to mimic a moderate TBI. One hour or twenty-four hours
after TBI, animals received intravenous infusion of saline (vehicle) or MB
(1mg/kg). MRI was utilized to longitudinally monitor T2 on days 0, 2, 7,
and 14 after TBI. Comparisons were made with the progression of lesion
volume, behavioral analysis (day 0, 2 7, and 14), and histology (day 14).
Vehicle-treated animals initial lesion volume grew larger by 92% and
peaked in size on day 2. By contrast, the acute and delayed MB-treated
groups lesion volume growth was smaller on day 2 compared to the ve-
hicle-treated group by 21% and 23%, respectively. Lesion volume in MB
treated rats continued to significantly decrease in lesion volume compared
to vehicle-treated rats on day 7 and 14 post-injury. Immunohistochemistry
confirmed final lesion volumes upon sacrifice on day 14. The behavioral
tests demonstrated impairment of motor function of vehicle- and MB-
treated rats on day 0 and 2. However, MB treated rats demonstrated im-
proved motor function by day 7, indicative of improved neurological
status. MBmarkedly reduces lesion size and improves behavioral outcome
even when delivered 24 hours post TBI. Delayed treatment would enable
increased therapeutic benefits to larger patient population. These results
suggest that restoration of mitochondrial function and minimizing reactive
oxygen species production is a promising neuroprotective strategy in TBI.
Keywords: Traumatic Brain Injury, Methylene Blue, MRI, Beha-
vioral analysis, Immunohistology
B2-08
TOXIC TAU SEEDS DERIVED FROM TRAUMATIC BRAIN
INJURY MODELS ACCELERATE COGNITIVE DYSFUNC-
TION IN TAUOPATHY MICE
Rakez Kayed
1
, Julia Gerson
1
, Diana Castillo-Carranza
1
, Urmi
Sengupta
1
, Donald Prough
2
, Douglas Dewitt
2
, Bridget Hawkins
2
1
University of Texas Medical Branch, Galveston, Neurology, Gal-
veston, USA
2
University of Texas Medical Branch, Galveston, Anesthesiology,
Galveston, USA
The aggregation of tau protein into neurofibrillary tangles (NFTs) in
the brain is a pathological feature of numerous neurodegenerative
A-48