East Carolina University : Research and Creative Achievement Week 2011
for later analysis. Drugs and control solutions were bath-applied for periods of 30-60 minutes. We found that the D2-like receptor agonist bromocriptine (10 µM) mimicked in the lumbar segments the responses previously observed with DA, but increased MSR in IML-containing segments (thoracic and sacral). In contrast, the highly specific D2-receptor antagonist raclopride (10 µM) had opposite effects, leading to a decrease in MSR in IML-containing spinal segments, and an increase in MSR in the lumbar segments without an IML. Additionally, blocking gap junctions with carbenoloxone led to loss of the differential response observed in the IML-containing segments. Our data indicate that the spinal autonomic system has an important modulatory control over the MSR, and they suggest that the actions of the IML on motoneurons are similar in the sympathetic or parasympathetic systems of the spinal cord. We are currently exploring the functional role of the IML/motoneuron connection as well as implications on physiological changes that may occur following spinal cord injury.
Characterizing the role of Psf2 in maintaining genomic integrity, Jeffrey Chmielewski, Laura Henderson, East Carolina University, Greenville, NC 27858 In D. melanogaster, the CMG complex is a group of proteins that function as the DNA helicase during replication. The CMG is composed of cdc45, MCM2-7, and the GINS complex. The GINS complex is a heterotetrameric complex composed of the protein subunits Psf1, Psf2, Psf3, and Sld5. Recent research in human dermal fibroblasts shows GINS is essential for the initiation and elongation stages of chromosomal replication. My primary hypothesis is that proper dosage of Psf2 is necessary to maintain genomic integrity, and there may be an interaction between Psf2 and Chk2 (loki) modulating DNA replication. Working with null mutations in Psf2 and Chk2, both separately and in combination, I have designed a series of experiments aimed at elucidating the function of Psf2. We are using DNA fiber analysis to determine if reduced expression of Psf2 alters the rate of the replication fork. In addition to DNA fiber analysis, we are investigating if reduced expression of Psf2 increases the incidences of ³H2AX foci, which could be indicative of Chk2 activation. Our lab has previously shown that the null mutation of Psf2 is homozygous lethal, we also have evidence of reduced viability in flies heterozygous for the null mutation. We are using acridine orange staining to determine if this reduced viability in flies heterozygous for the null mutation is a consequence of an increase in apoptosis.
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Morphological Correlates of Gravity Receptor Functional Aging in CBA/CaJ Mice, Jessica Pierce, Sarath Vijayakumar, Sherri M. Jones, East Carolina University, Greenville, NC 27858 P19 Cdh23ahl (Ahl) is a genetic mutation located on mouse chromosome 10 that affects Cadherin23, a protein critical to sensory transduction. Ahl predicts age-related hearing loss; however, it may not predict vestibular functional aging. We are currently assessing vestibular functional and structural aging, and hypothesized that morphological aging of vestibular structures correlate with gravity 114