Virginia Tech® home

Thesis Defense: Functions of Mediodorsal Thalamic Astrocytes in Cue-Based Learning

Insert your title here

Your Text Here
KM

Thesis Defense: Functions of Mediodorsal Thalamic Astrocytes in Cue-Based Learning

Visit the Howe Lab

Katie Marschalko

Graduate Student, Translational Biology, Medicine, and Health
Graduate Research Assistant, Howe Lab
December 10, 2024, at 9:00a.m.
Room 101, Life Science 1

About this Thesis

To successfully navigate daily life, organisms must be able to identify stimuli that are predictive of beneficial outcomes1,2. A key thalamic nucleus involved in this process is the mediodorsal thalamus (MD), which bidirectionally communicates with the prefrontal cortex, facilitating cognitive and decision-making functions. Despite the MD's involvement in higher-order relays, the precise mechanisms underlying its astrocytic activity, its contribution to synaptic plasticity, and the subsequent effects on cognitive processing remain poorly understood. Emerging data highlights the pivotal role of astrocytes in regulating synaptic transmission, with astrocytic calcium activity being linked to gliotransmitter release3,4. Abnormalities in astrocytic calcium activity have been found to impair learning and memory, thus insights into their mechanism during cognitive processes in the MD could reveal novel targets for investigating cognitive disorders5,6. In this study, we investigated astrocytic activity during a cue-based learning task, uncovering notable differences in the timing of astrocytic calcium release between early and late stages of the task. To investigate plasticity-related changes between early and late stages, the colocalization of astrocytes, glutamatergic nerve terminals, and astrocyte glutamate transporter proteins will be examined. We found that MD astrocytic calcium activity responds to the initial cue and the reward, suggesting that this activity mediates the temporal dynamics of synaptic plasticity, influencing how thalamic circuits adjust to both cues and outcomes during learning.

More About the Candidate and Project

Education

Virginia Tech, Translational Biology, Medicine, and Health, M.S. Student

Virginia Tech, B.S. Clinical Neuroscience

Training

Graduate Research Assistant, Howe Lab

Mentor

William "Matt" Howe, Ph.D., Assistant Professor, School of Neuroscience

Committee Members

  • Michael Fox, Ph.D., Dean, College of Natural Sciences at University of Massachusettes Amherst
  • Sarah Clinton, Ph.D., Associate Professor and Associate Director of IHSR
  • Alexandra DiFeliceantonio, Ph.D., Assistant Professor, Interim Co-director, Center for Health Behaviors Research

Publications

Runyon, K., Bui, T., Mazanek, S., Hartle, A., Marschalko, K., & Howe, W. M. (2024). Distinct cholinergic circuits underlie discrete effects of reward on attention. Frontiers in Molecular Neuroscience, 17, 1429316.

Presentations

ORAL PRESENTATIONS
Katie Marschalko, Nick Damiano, Emily York, Alec Hartle, Kelly Runyon, W. Matt Howe (October, 2024).Ca+2 dynamics in mediodorsal thalamic astrocytes track cue-reward learning. Poster presented at the Society for Neuroscience Meeting, Chicago, Illinois

Runyon, K., Greenway, A., Mazanek, S., Sallee, C., Hartle, A., & Marschalko, K., Howe, W.M. (November 2022). Neuromodulation of a thalamo-cortical cue detection circuit. Poster presented at the Society for Neuroscience Meeting, San Diego, California.

Hartle, A., Sisco, J., Marschalko, K., Runyon, K., DiFeliceantonio, A., Howe, M. (November 2021). Unique effects of macronutrient combinations on dopamine release and food choice. Talk presented at the Society for Neuroscience Meeting, Virtual.

Hartle, A., Sisco, J., Runyon, K., Marschalko, K., DiFeliceantonio, A., Howe, M. (July 2021). Macronutrient modulation of food reward. Poster presented at the Society for the Study of Ingestive Behavior Meeting, Virtual.

POSTER PRESENTATIONS
Marschalko, K., Tatera, W., Sallee, C., Damiano, N., Howe, M. (December, 2023) The Impacts of Satiety States on the Dorsolateral Parabrachial to Central Amygdala Cholinergic Circuit. Presented in the Fralin Biomedical Research Institute for the Translational Biology Medicine and Health Graduate Program.

Tatera, W., Sisco, J., Marschalko, K., Howe, M. (February, 2022) Function of Cholinergic Projections from the Lateral Parabrachial Nucleus to Central Amygdala. Presented in Life Sciences 1 for the Translational Biology Medicine and Health Graduate Program.


Blankenship, M., Haueis, J., Marschalko, K., Russell, N., Solomon, B., Impacts of Soil pH Change in Genetically Modified Arabidopsis thaliana Plants. Presented at Moss Arts Center.

Honors and Awards

TBMH Shark Tank Second Place 2022

Service