Student Seminars

Stacey Pedraza & Gavin Magill - PhD Candidates

Titles: TBD

Faculty Evaluators: Ed Freedman & Krystel Huxlin

Student Moderator: Catalina Guzman

 Mar 03, 2025 @ 4:00 p.m.
 Medical Center | K307

Bryan V. Redmond - PhD Candidate, Neuroscience Graduate Program

Cortically induced blindness (CB), which most often results from stroke damage to the primary visual cortex (V1) or its afferents,
leads to binocular loss of conscious visual perception. While motor stroke rehabilitation is well-researched, the visual deficits
faced by CB patients lack effective treatment, with only compensatory therapies like saccadic training and prism lenses
prescribed clinically. CB is considered permanent, offering little hope for visual recovery. However, recent research from the
Huxlin lab and others has challenged this notion, demonstrating the potential for recovering direction discrimination abilities -
among others - within the blind field. In addition, building on the pioneering work of Riddoch and Weiskrantz, Saionz and
colleagues (2020) reported that about 1/3 of naïve, early post-occipital stroke patients retain a range of preserved conscious
simple and complex motion abilities. More rarely, some even retained the ability to discriminate orientation of static targets
within their perimetrically-defined blind fields. Whether with different perimetric tests or psychophysical tasks, evidence is
mounting supporting the heterogeneity of perception inside CB fields. A next step is to identify and understand the natural
history of these abilities, what anatomical structures enable them, and what their presence means for rehabilitation.

The first step in this endeavor is to define the deficit. Humphrey automated perimetry (HAP) is the most common type of clinical
perimetry used in CB. It measures light detection using a small, static stimulus, presented randomly in a grid-like pattern across
the central visual field. However, it does not control fixation during testing as rigorously as the Macular Integrity Assessment
(MAIA) perimeter. We contrasted these two perimeters’ ability to identify visual impairment and assess changes both
spontaneously and following restorative interventions. We concluded that on the sum, HAP performed according to strict test
quality criteria is the most optimal way to quickly but coarsely define the extent and severity of the deficit in CB. Based on HAPdefined
blind-field boundaries, we then proceeded to map motion discrimination in the blind-field. Our standard method for
identifying preservation of such abilities involved repeatedly and densely testing a few, adjacent blind field locations using
random dot stimuli. Although precise, this approach is time-consuming, and oversamples a very small region of visual space
rather than canvassing the entire deficit. This limitation makes it impractical for clinical use, leaving most patients uninformed
about the truly heterogenous nature of their “blind” field.

This thesis addresses this gap, developing an automated, direction discrimination perimetric tool (ADDaPT) able to rapidly and
accurately detect preserved motion discrimination abilities across the HAP-defined blind-field of CB patients. Then, using the
new ADDaPT definition of preservation in concert with computerized, home-based training, we compare the efficacy of training
in preserved and non-preserved CB patients. In addition, we correlated performance outcomes with the progression of
retrograde degeneration affecting the ganglion cell and inner plexiform layers of the retina, measured using optical coherence
tomography at baseline and 12-months post-stroke.

Flyer

 Mar 05, 2025 @ 9:00 a.m.
 Eastman Dental Center | EIOH Farash Auditorium (1st floor EDC)

Margaux C. Masten - PhD Candidate, Neuroscience Graduate Program

There is a growing body of epidemiological evidence linking air pollution (AP) exposure and increased risk for multiple childhood onset neurodevelopmental disorders (NDDs) including attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Exposure to AP in the third trimester of pregnancy has been linked with higher odds of ASD diagnosis, as well as, more symptoms of inattention and decreased corpus callosum (CC) volume associated with increased hyperactivity. Ultrafine particulate matter (UFP) is one of the most reactive components of AP, due to its large surface area to volume ratio. Furthermore, UFPs present a unique challenge as their small size allow them to penetrate deep into the lungs and traverse many of the body’s barrier mechanisms such as the placenta and the blood brain barrier, creating a unique challenge for the developing brain during gestation. Previous work from our lab in C57BL/6J mice shows that gestational and early postnatal exposures to ambient UFP from traffic related air pollution trigger unique sex-dependent neurobehavioral outcomes, with ventriculomegaly, alterations in myelination of the CC, persistent CC microglial activation, elevated glutamate in the brain, metal dyshomeostasis, and behavioral deficits including impulsivity, cognitive inflexibility, and altered social interaction. However, the sex-difference and directionality of these effects vary between gestational and post-natal exposures. Due to the altricial brain development at birth in traditional laboratory rodents, we do not know if the differences are due to critical windows of exposure or differential routes of exposure. Unlike C57BL/6J mice, the African Spiny mouse (genus Acomys) is born precocial with neural development more similar to humans at the time of birth. This unique model allows us to test the neurotoxicity of air pollution during late gestation with a more translational pattern of brain development. In addition to their precocial brain development at birth, spiny mice are highly social animals allowing for more expanded social behavioral evaluations. The central hypothesis of this thesis is that late gestational UFP exposure induces neurodevelopmental changes in spiny mice similar to the effects seen in postnatal C57BL/6J UFP exposures, including altered white matter development, cognitive inflexibility, and social behavioral deficits.

Experiments from Aim 1 will use transmission electron microscopy to characterize UFP metal contaminants and particle characteristics across maternal cranial nerves, maternal olfactory bulbs, placenta, and the periventricular region of the fetal brain. We hypothesize that inhaled UFP from the dam will translocate across the placenta and into the pup brain and will show differential bioprocessing in the maternal and fetal brains. In Aim 2 we will use electron microscopy and immunohistochemistry to identify changes in myelination and white matter tracts. We hypothesize that exposure in the spiny mice will lead to white matter damage with decreased corpus collosum size, altered myelin ultrastructure, and enlarged lateral ventricles in a male-biased manner. Experiments from Aim 3 will test social interaction and cognitive flexibility using behavioral paradigms including measures of social interaction and communication as well as the translationally relevant ID/ED shift operant task. We predict there will be sex-dependent deficits in social communication and cognitive flexibility in spiny mice exposed to UFP during the late gestational period in utero. Together these experiments will expand our understanding of how late gestational exposure to air pollution confers risk for multiple neurodevelopmental disorders that share sex-biased prevalence rates and behavioral presentations.

 Mar 07, 2025 @ 12:00 p.m.
 Medical Center | Adolph Lower Aud. (1-7619)

Tom Scudder & Lelo Shamambo - PhD Candidates

Titles: TBD

Faculty Evaluators: Doug Portman & Marissa Sobolewski

Student Moderator: Abigail Alpers

 Mar 17, 2025 @ 4:00 p.m.
 Medical Center | K307

Brian Keane, PhD; James L. McGrath, PhD; Katrina S. Korfmacher, PhD - Assistant Professor; William R. Kenan Jr. Professor of Biomedical Engineering; Professor

Please join us for the next Seeds for Collaboration event which will held on Wednesday, 3/19, at 4:30 PM in the LeChase Assembly Rm, G9576.  See the seminar announcement attached for further information. 

Presenters include:

Katrina S. Korfmacher, PhD
Professor of Environmental Medicine and Director of Community Engagement for the Environmental Health Sciences Center (EHSC) and the Institute for Human Health and the Environment
“Moving Forward with Reporting Back Environmental Health Research Results”

 
Brian Keane, PhD
Assistant Professor, Psychiatry, Neuroscience, Center for Visual Science, Brain and Cognitive Sciences
“A Novel Sensory Dysconnectivity Biomarker for Psychosis: Searching for Mechanisms and Transdiagnosticity”

 
James L. McGrath, PhD
William R. Kenan Jr. Professor of Biomedical Engineering
“Building the Vulnerable Brain On-a-Chip”

Seminar Announcement

 Mar 19, 2025 @ 4:30 p.m.
 Medical Center | LeChase Assembly Rm. (G9576)

Sean Lydon & Estephanie Balb - PhD Candidates

Titles: TBD

Faculty Evaluators: Benjamin Suarez-Jimenez & Samuel MacKenzie

Student Moderator: Dominic Bunn

 Mar 24, 2025 @ 4:00 p.m.
 Medical Center | K307

Gueladouan Jean Setenet & Pavel Rjabtsenkov - PhD Candidates

Titles: TBD

Faculty Evaluators: Thomas O'Connor & Amy Kiernan

Student Moderator: Andrea Campbell

 Mar 31, 2025 @ 4:00 p.m.
 Medical Center | K307

Adam Roszczyk & Caleb Mahlen - PhD Candidates

Titles: TBD

Faculty Evaluators: Manoela Fogaca & Andrew Wojtovich

Student Moderator: Tanique McDonald

 Apr 07, 2025 @ 4:00 p.m.
 Medical Center | K307

Tracey Preko & Skylar DeWitt - PhD Candidates

Titles: TBD

Faculty Evaluators: Samuel Norman-Haignere & Ania Busza

Student Moderator: Amelia Hines

 Apr 14, 2025 @ 4:00 p.m.
 Medical Center | K307

Wen Li & Yunshan Cai - PhD Candidates

Titles: TBD

Faculty Evaluators: Rick Libby & Ed Brown

Student Moderator: Mariah Marrero

 Apr 21, 2025 @ 4:00 p.m.
 Medical Center | K307

Joanne Chiu & Emma Bryson - PhD Candidates

Titles: TBD

Faculty Evaluators: Jean Bidlack & David Dodell-Feder

Student Moderator: Daulton Myers

 Apr 28, 2025 @ 4:00 p.m.
 Medical Center | K307

Alesandra Martin & Emma Strawderman - PhD Candidates

Titles: TBD

Faculty Evaluators: Michael Telias & Frank Garcea

Student Moderator: Jeeyun Kim

 May 05, 2025 @ 4:00 p.m.
 Medical Center | K207

Alex Solorzano & Alexis Feidl - PhD Candidates

Titles: TBD

Faculty Evaluators: John Olschowka & Debroah Cory-Slechta

Student Moderator: Margaux Masten

 May 12, 2025 @ 4:00 p.m.
 Medical Center | K207

Catalina Guzman - PhD Candidate

Title: TBD

Faculty Evaluators: Ania Majewska & Loisa Bennetto

Student Moderator: Gavin Magill

 May 19, 2025 @ 4:00 p.m.
 Medical Center | K207