Research Projects

Below are spotlights of recent honors projects for the neuroscience program.
Honors profile of Warsameh Bulhan, Class of 2022
Warsameh Buhlen ’22

Thesis: "Characterizing Toll Receptors in the Mediterranean Cricket"

Abstract: The Mediterranean field cricket, Gryllus bimaculatus, is a great model organism to learn more about adult central nervous system (CNS) plasticity as it demonstrates compensatory plasticity. Studies found that the Toll signaling pathway is enriched after auditory system injury. Toll receptors are known to be involved in the development/neuronal survival of invertebrates. The Toll pathway is also predicted to function as neurotrophins in insects. Here, we characterized Toll receptors in the cricket by constructing phylogenetic trees and conducting PCRs and whole-mount in situ hybridization (ISH) experiments. Bando and colleagues (2021) predicted that there were 11 Tolls in Gryllus bimaculatus. Our phylogenetic tree results predicted this as well. PCR results indicated that Toll 6-1, 6-2 and Toll 7 were all present in the cricket embryos. However, although Toll 6-1 and 7 were present in the cricket prothoracic ganglia (PG) and brain, Toll 6-2 was found only in the prothoracic ganglia. ISH results illustrated a weaker more distributed expression of Toll 7 in the mushroom bodies (MBs) of the cricket brain. Toll 6-1 was found strongly expressed in the cricket brain in the area posterior to the MBs, while there was weaker and more diffuse staining in the MBs. There was little obvious expression of Toll 7 in the PG while Toll 6-1 expression was evident in bands; Toll 6-1 was also expressed in the midline of the PG. Both Toll 7 and Toll 6-1 were expressed in embryo limb buds, but they showed up in a striped and spotted pattern respectively.

Most memorable neuroscience course: Molecular Neurobiology with Hadley Horch

Since graduating: I am preparing to be a clinical research coordinator at Massachusetts General Hospital.

Honors profile of Alissa Chen, Class of 2022
Alissa Chen ’22

Thesis: "Sex- and age-specific susceptibility of parvalbumin neurons to DNA methylation in a model of early life adversity"

Abstract: Children who have experienced caregiver deprivation are more likely to develop neuropsychiatric disorders like anxiety, a disorder which affects women more than men and demonstrates onset typically during late adolescence/early adulthood. In rats that have experienced early life adversity (ELA) via maternal separation, increased sex- and age-dependent anxiety-like behavior has been associated with disruption in parvalbumin (PV) cell count and function in inhibitory interneurons in the prefrontal cortex’s infralimbic region. Circuits associated with anxiety-like behavior and regulation are perturbed. The present study found that regardless of exposure to ELA, males and females demonstrated a decrease in anxiety-like behavior in young adulthood (postnatal day (P)45) compared to juvenility (P25). Neural analyses of total 5mc (a marker of DNA methylation) intensity, PV count, and 5mc intensity within PV cells showed an increase in total 5mc intensity with a decrease in anxiety-like behavior in P25 females. Males exposed to ELA showed an increase in 5mc intensity at P45 compared to P25. These results overall indicate that females may be susceptible to changes in 5mc intensity that lead to changes in anxiety-like behavior, whereas males’ changes in 5mc intensity in PV cells may not. These findings underscore the importance of investigating sex- and age-specific 5mc methylation in PV cells that may underlie, or be predictive of, increased anxiety following ELA during specific developmental windows.

Most memorable neuroscience course: Molecular Neurobiology with Hadley Horch

Since graduating: As of mid-June 2022, I just came back from Glasgow, Scotland, from the International Behavioral Neuroscience Society conference with my PI [primary investigator] Jennifer Honeycutt and labmates Seneca Ellis ’22 and Sydney Bonauto ’23. I had an incredible experience meeting authors of papers I constantly cite and presenting a poster on my honors thesis to renowned experts from all over the world. Next month, I will be working at Mount Sinai’s Icahn School of Medicine as a clinical research coordinator with Daniela Schiller and Jennifer Foss-Feig, continuing my work in affective neuroscience, and hoping to apply to medical school.

Honors profile of Anthony Yanez, Class of 2022
Anthony Yanez ’22

Thesis: "Effects of myosuppressin, a peptide neuromodulator, on membrane currents in the crustacean cardiac ganglion"

Abtsract: Central pattern generators are neural circuits that can independently produce rhythmic patterns of electrical activity without central or periphery inputs. They control rhythmic behaviors like breathing in humans and cardiac activity in crustaceans. Rhythmic behaviors must be flexible to respond appropriately to a changing environment; this flexibility is achieved through the action of neuromodulators. The cardiac ganglion of Homarus americanus, the American lobster, is a central pattern generator made up of four premotor neurons and five motor neurons. Membrane currents in each cell type, which can be targeted for modulation by various molecules, generate rhythmic bursts of action potentials. Myosuppressin, a FMRFamide-like peptide, is one such neuromodulator. The currents targeted for neuromodulation by myosuppressin are unknown. I investigated the molecular and physiological underpinnings of the modulatory effect of myosuppressin on motor neurons in the cardiac ganglion. First, using single cell RT-qPCR, I determined that across animals, motor neurons express myosuppressin receptor subtype II at equal levels relative to each other. Using sharp intracellular recordings, I showed that myosuppressin decreased burst frequency and the rate of depolarization during the inter-burst interval. I predicted that this effect resulted from the modulation of either A-type potassium current or calcium-dependent potassium current. Using two-electrode voltage clamp, I found that total outward current did not substantially change after treatment with myosuppressin. This result was surprising and provides grounds for explorations of subtle forms of neuromodulation in simple neural circuits.

Most memorable neuroscience course: Neurophysiology with Patsy Dickinson

Since graduating: I’m currently working as an Intramural Research Training Award (IRTA) postbaccalaureate fellow at the National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health. Specifically, I’m working in the cellular neurophysiology unit to study dopamine neurons and the pathophysiology underlying Parkinson’s disease. After my time at NINDS, I’ll apply to graduate school to earn a PhD in neuroscience.

Read about Anthony Yanez's Goldwater Scholarship.