(Georgia Institute of Technology, 2021-05)
Pfahl, Emily Lynn
Oxaliplatin (OX) is a widely used chemotherapy compound used in the treatment of colorectal cancers (CRCs). Patients treated with OX often exhibit severe side effects, including motor dysfunction and imbalance, potentially influenced by the inability of sensory neurons, including muscle spindle afferents (MSAs), to repetitively fire, which is needed to properly encode information about limb movement. Even though OX is prescribed in a majority of CRCs, it is currently unknown how the compound causes the aforementioned side effects. The aim of the present study was to determine if OX acts through modification of the voltage-gated potassium channel Kv3.3, which is hypothesized to promote repetitive firing. To test this hypothesis, the soleus nerve and muscle were isolated from control mice. A series of ramp and triangular stretches were applied to the muscles, and afferent firing responses were recorded. A synthetic Kv3.3-knockdown line of mice was created using Kv3.3 siRNA (ThermoFischer Scientific). The soleus nerve and muscle were isolated from these mice, the same stretches were applied to the muscle, and MSA recordings were taken and compared to the control MSA responses. Preliminary data suggest that afferent responses to stretch are altered in the Kv3.3-knockdown mice, but as of this time, not enough data has been collected to make statistically significant claims. Future work will focus on collecting enough Kv3.3-knockdown data to perform statistical analyses on the data, as well as on performing immunohistochemical (IHC) staining of tissue from knockdown animals to ensure silencing of Kv3.3.
(Georgia Institute of Technology, 2020-05)
Palanivel, Shivani
Neural stem cells (NSCs) are important multipotent adult stem cells capable of
self-renewal and differentiation into various cell types present in the central nervous system. Studying the characteristics of NSCs and their differentiation offers insights into developmental mechanisms and allows us to assess their utility in vitro disease modeling and neurotoxicological research.
This study investigates the properties of NSC during propagation and differentiation in culture. Neurospheres, formed from NSC aggregates, were cultured and examined for morphology and growth rate by cell counting and size analysis. Neurospheres were induced to differentiate toward neural network formation. The expression of markers of NSC and astrocytes in neurospheres during differentiation was detected by immunostaining methods. NSC multiplied with an exponential proliferation rate accompanied by a steady increase in neurosphere diameter. The neurosphere cells expressed Nestin, an NSC/ progenitor cell marker, when cultured in self-renewal media, and displayed pronounced GFAP expression after induction of differentiation indicating a prevalence of astrocytes. Further studies will provide better understanding of NSC characteristics that may be applied for the advancement of stem cell therapy to help combat neurodegenerative diseases.