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Browsing Virginia Tech Carilion (VTC) by Subject "1109 Neurosciences"
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- Dear reviewers: Responses to common reviewer critiques about infant neuroimaging studiesKorom, Marta; Camacho, M. Catalina; Filippi, Courtney A.; Licandro, Roxane; Moore, Lucille A.; Dufford, Alexander; Zöllei, Lilla; Graham, Alice M.; Spann, Marisa; Howell, Brittany R.; Shultz, Sarah; Scheinost, Dustin (Elsevier, 2022-02-01)The field of adult neuroimaging relies on well-established principles in research design, imaging sequences, processing pipelines, as well as safety and data collection protocols. The field of infant magnetic resonance imaging, by comparison, is a young field with tremendous scientific potential but continuously evolving standards. The present article aims to initiate a constructive dialog between researchers who grapple with the challenges and inherent limitations of a nascent field and reviewers who evaluate their work. We address 20 questions that researchers commonly receive from research ethics boards, grant, and manuscript reviewers related to infant neuroimaging data collection, safety protocols, study planning, imaging sequences, decisions related to software and hardware, and data processing and sharing, while acknowledging both the accomplishments of the field and areas of much needed future advancements. This article reflects the cumulative knowledge of experts in the FIT'NG community and can act as a resource for both researchers and reviewers alike seeking a deeper understanding of the standards and tradeoffs involved in infant neuroimaging.
- Early influences of microbiota on white matter development in germ-free pigletsAhmed, Sadia; Travis, Sierrah; Díaz-Bahamonde, Francisca; Porter, Demisha; Henry, Sara; Ravipati, Aditya; Booker, Aryn; Ding, Hanzhang; Ju, Jing; Ramesh, Ashwin; Pickrell, Alicia M.; Wang, Maosen; LaConte, Stephen M.; Howell, Brittany R.; Yuan, Lijuan; Morton, Paul D. (Frontiers, 2021-12-27)Abnormalities in the prefrontal cortex (PFC), as well as the underlying white matter (WM) tracts, lie at the intersection of many neurodevelopmental disorders. The influence of microorganisms on brain development has recently been brought into the clinical and research spotlight as alterations in commensal microbiota are implicated in such disorders, including autism spectrum disorders, schizophrenia, depression, and anxiety via the gut-brain axis. In addition, gut dysbiosis is common in preterm birth patients who often display diffuse WM injury and delayed WM maturation in critical tracts including those within the PFC and corpus callosum. Microbial colonization of the gut aligns with ongoing postnatal processes of oligodendrogenesis and the peak of brain myelination in humans; however, the influence of microbiota on gyral WM development remains elusive. Here, we develop and validate a neonatal germ-free swine model to address these issues, as piglets share key similarities in WM volume, developmental trajectories, and distribution to humans. We find significant region-specific reductions, and sexually dimorphic trends, in WM volume, oligodendrogenesis, and mature oligodendrocyte numbers in germ-free piglets during a key postnatal epoch of myelination. Our findings indicate that microbiota plays a critical role in promoting WM development during early life when the brain is vulnerable to environmental insults that can result in an array of disabilities manifesting later in life.
- Maltreatment and brain development: The effects of abuse and neglect on longitudinal trajectories of neural activation during risk processing and cognitive controlKim-Spoon, Jungmeen; Herd, Toria; Brieant, Alexis; Peviani, Kristin; Deater-Deckard, Kirby; Lauharatanahirun, Nina; Lee, Jacob; Casas, Brooks (Elsevier, 2021-04-01)The profound effects of child maltreatment on brain functioning have been documented. Yet, little is known about whether distinct maltreatment experiences are differentially related to underlying neural processes of risky decision making: valuation and control. Using conditional growth curve modeling, we compared a cumulative approach versus a dimensional approach (relative effects of abuse and neglect) to examine the link between child maltreatment and brain development. The sample included 167 adolescents (13–14 years at Time 1, 53 % male), assessed annually four times. Risk processing was assessed by blood-oxygen-level-dependent responses (BOLD) during a lottery choice task, and cognitive control by BOLD responses during the Multi-Source Interference Task. Cumulative maltreatment effects on insula and dorsolateral anterior cingulate cortex (dACC) activation during risk processing were not significant. However, neglect (but not abuse) was associated with slower developmental increases in insula and dACC activation. In contrast, cumulative maltreatment effects on fronto-parietal activation during cognitive control were significant, and abuse (but not neglect) was associated with steeper developmental decreases in fronto-parietal activation. The results suggest neglect effects on detrimental neurodevelopment of the valuation system and abuse effects on accelerated neurodevelopment of the control system, highlighting differential effects of distinct neglect versus abuse adverse experiences on neurodevelopment.
- Potassium and glutamate transport is impaired in scar-forming tumor-associated astrocytesCampbell, Susan C.; Muñoz-Ballester, Carmen; Chaunsali, Lata; Mills, William A.; Yang, Jennifer H.; Sontheimer, Harald; Robel, Stefanie (Elsevier, 2019-12-09)Unprovoked recurrent seizures are a serious comorbidity affecting most patients who suffer from glioma, a primary brain tumor composed of malignant glial cells. Cellular mechanisms contributing to the development of recurrent spontaneous seizures include the release of the excitatory neurotransmitter glutamate from glioma into extracellular space. Under physiological conditions, astrocytes express two high affinity glutamate transporters, Glt-1 and Glast, which are responsible for the removal of excess extracellular glutamate. In the context of neurological disease or brain injury, astrocytes become reactive which can negatively affect neuronal function, causing hyperexcitability and/or death. Using electrophysiology, immunohistochemistry, fluorescent in situ hybridization, and Western blot analysis in different orthotopic xenograft and allograft models of human and mouse gliomas, we find that peritumoral astrocytes exhibit astrocyte scar formation characterized by proliferation, cellular hypertrophy, process elongation, and increased GFAP and pSTAT3. Overall, peritumoral reactive astrocytes show a significant reduction in glutamate and potassium uptake, as well as decreased glutamine synthetase activity. A subset of peritumoral astrocytes displayed a depolarized resting membrane potential, further contributing to reduced potassium and glutamate homeostasis. These changes may contribute to the propagation of peritumoral neuronal hyperexcitability and excitotoxic death.
- Processes linking socioeconomic disadvantage and neural correlates of cognitive control in adolescenceBrieant, Alexis; Herd, Toria; Deater-Deckard, Kirby; Lee, Jacob; Casas, Brooks; Kim-Spoon, Jungmeen (Elsevier, 2021-04-01)Socioeconomic status (SES) is broadly associated with self-regulatory abilities across childhood and adolescence. However, there is limited understanding of the mechanisms underlying this association, especially during adolescence when individuals are particularly sensitive to environmental influences. The current study tested perceived stress, household chaos, parent cognitive control, and parent-adolescent relationship quality as potential proximal mediators of the association between family SES and neural correlates of cognitive control. A sample of 167 adolescents and their primary caregivers participated in a longitudinal study across four years. SES was indexed by caregivers’ education and income-to-needs ratio at Time 1. At Time 2, adolescents reported on their perceived stress, household chaos, and relationship with parents, and parents completed a cognitive control task. Two years later, adolescents completed the same cognitive control task while blood-oxygenation-level-dependent (BOLD) response was monitored with functional magnetic resonance imaging (fMRI). A parallel mediation model indicated that parent cognitive control, but not other proximal factors, explained the relation between SES and adolescents’ activation in the middle frontal gyrus during a cognitive control task. The results suggest potential targets for intervention and prevention efforts that may positively alter neurocognitive outcomes related to socioeconomic disadvantage.