Who We Are

Greg Valdez, Ph.D. of the Virginia Tech Carilion Research Institute. (David Hungate/ Virginia Tech Carilion Research Institute)

Gregorio Valdez, Primary Investigator

My overarching goal is to develop treatments to preserve and restore the health and function of neurons, muscles and their synapses in old age, and those which are affected by diseases and injuries. In particular, I seek to identify endogenous and exogenous molecules with critical roles in maintaining cellular health. In addition to research, I am passionate about teaching and mentoring students at all stages of their careers.

Thomas Taetzsch, Postdoctoral Fellow

My research focuses on characterizing the function of the fibroblast growth factor binding protein (FGFBP1) at synapses and in skeletal muscles. In another line of research, I am studying the role of synaptically-enriched microRNAs in skeletal muscles.  In addition, I am investigating the integrity of the RISC-complex, molecules required for microRNA biogenesis and function, in disease conditions.

Thomas Taetzsch of the Virginia Tech Carilion School   Research Institute. (David Hungate for VTCRI)

Sydney Vaughan, Postdoctoral Fellow

I have been investigating the role of cholinergic transmission in the maintenance of NMJs and skeletal muscles. Using transgenic animal models, I have shown that modulating cholinergic signaling at the NMJ can have negative consequences. Furthermore, I am currently exploring how the protein Lynx1 is involved in regulating cholinergic transmission in skeletal muscles. Lynx1 was previously classified as an endogenous cholinergic modulator through neuronal nicotinic acetylcholine receptors (nAChRs). However, while cholinergic signaling through nAChRs is the main driving force of skeletal muscle contraction, the role of Lynx1 in muscles has largely been overlooked. Using molecular, biochemical, electrophysiological, and imaging techniques I am studying the role of Lynx1 in developing, injured, and disease-affected skeletal muscles and NMJs.

Ryan Castro, Graduate Student

My thesis work is focused on identifying age-related changes in the spinal cord that may lead to motor deficits associated with aging. My research involves the analysis of molecular and morphological features of spinal cord resident neurons and their synapses, with a particular focus on α-motor neurons. Additionally, I am interested in age-related changes undergone by glial cells, primarily microglia and astrocytes, and their possible effect on neuronal and synaptic health and efficacy.

Castro- Ryan002 is with the TBMH program at the Virginia Tech Carilion Research Institute.  (David Hungate for VTCSOMRI)

Dillon Shapiro, Graduate Student

As a graduate student in the Valdez lab, my work is principally aimed at furthering our understanding of how the cells and synapses of the brain are impacted by the aging process. How changes to these structures accumulate with time, how different cell types are individually affected, how these changes contribute to the development of age-associated disease, and how to intervene in or mitigate these processes are the questions that my work strives to address.

Undergraduate Students

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Noel Kim

I am a part of Brown University’s class of 2022, pursuing a ScB in Biology. I hope to work in either medical research or practice medicine in the future. In the lab, I am being mentored by Ryan to complete a project investigating the impact of aging on spinal cord microglia.

Valdez Lab Photo

Devin Juros

As a member of Brown’s class of 2023, I am concentrating in Biology, with the aim of pursuing medical research as a future career. In the lab, I hope to contribute to a project related to the impact of synaptic transmission on the degeneration of skeletal muscle function with age and neuromuscular disorders.


Anson O'Young

I am a member of Brown’s class of 2022 with the goal of a ScB in Biochemistry & Molecular Biology. I hope to work in the medical field in the future. In the lab, I am working in tandem with Jason under the guidance of Sydney to investigate how aging impacts the neuromuscular junction. To this end, I have been analyzing NMJ imaging in EDL muscles for fragmentation and PSC count.


Jessica Chau

I am a part of Brown's Class of 2022 and am pursuing an Sc.B in Cellular and Molecular Biology. I hope to either pursue a medical degree to practice medicine or enter medical research in the future. In the lab, I am being mentored by Ryan to complete a project investigating the role of microglia in aging.