Glutamate Electropolymerization on Carbon Increases Analytical Sensitivity to Dopamine and Serotonin: An Auspicious In Vivo Phenomenon in Mice?

Carbon is the material of choice for electroanalysis of biological systems, being particularly applicable to neurotransmitter analysis as carbon fiber microelectrodes (CFMs). CFMs are most often applied to dopamine detection; however, the scope of CFM analysis has rapidly expanded over the last decade with our laboratory's focus being on improving serotonin detection at CFMs, which we achieved in the past via Nafion modification. We began this present work by seeking to optimize this modification to gain increased analytical sensitivity toward serotonin under the assumption that exposure of bare carbon to the in vivo environment rapidly deteriorates analytical performance. However, we were unable to experimentally verify this assumption and found that electrodes that had been exposed to the in vivo environment were more sensitive to evoked and ambient dopamine. We hypothesized that high in vivo concentrations of ambient extracellular glutamate could polymerize with a negative charge onto CFMs and facilitate response to dopamine. We verified this polymerization electrochemically and characterized the mechanisms of deposition with micro- and nano-imaging. Importantly, we identified that the application of 1.3 V as a positive upper waveform limit is a crucial factor for facilitating glutamate polymerization, thus improving analytical performance. Critically, information gained from these dopamine studies were extended to an in vivo environment where a 2-fold increase in sensitivity to evoked serotonin was achieved. Thus, we present here the novel finding that innate aspects of the in vivo environment are auspicious for detection of dopamine and serotonin at carbon fibers, offering a solution to our goal of an improved fast-scan cyclic voltammetry serotonin detection paradigm.

Exploring Food-Based Cultural Practices to Address Food Insecurity in Rural Appalachia.

BACKGROUND: Health behaviors, like diet, are influenced by a person's culture and the society where they reside, contributing to the presence of health disparities within a unique region. Such disparities are evident in Central Appalachia where a unique cultural identity exists. Culture-based initiatives focused on improving food security and other nutritional challenges have had success in other diverse groups, yet similar interventions considering geographically tied culture, like Appalachia, are limited. AIM: This study aims to identify specific aspects of Appalachian culture that address food insecurity to inform future initiatives that may improve adult dietary habits and food security status. METHODS: Qualitative data were collected from five focus groups in one rural Central Appalachian community in 2021 (n=59). Data were analyzed using Grounded Theory Approach. RESULTS: Four primary themes related to culture and food insecurity emerged: 1) Community decline and economic hardship 2) Shifts in multigenerational food traditions 3) Response to limited food access and 4) Community decline and economic hardship. Participants revealed adaptations they have made in the face of geographic isolation and poverty and the pride they take in providing for themselves and one another. CONCLUSION: These findings indicate the people of Appalachia are unknowingly leveraging cultural practices to address food insecurity, yet the impact of these practices on nutritional status remains unknown. These results have implications for future studies and interventions in Appalachia which may have greater success by accounting for cultural influences compared to traditional approaches for reducing food insecurity in the region.

Low-Frequency Oscillations of In Vivo Ambient Extracellular Brain Serotonin.

Serotonin is an important neurotransmitter that plays a major role in many aspects of neuroscience. Fast-scan cyclic voltammetry measures fast in vivo serotonin dynamics using carbon fiber microelectrodes. More recently, fast-scan controlled-adsorption voltammetry (FSCAV) has been developed to measure slower, minute-to-minute changes in ambient extracellular serotonin. We have previously demonstrated that FSCAV measurements of basal serotonin levels give critical information regarding brain physiology and disease. In this work, we revealed the presence of low-periodicity fluctuations in serotonin levels in mouse hippocampi, measured in vivo with FSCAV. Using correlation analyses, we found robust evidence of oscillations in the basal serotonin levels, which had a period of 10 min and were not present in vitro. Under control conditions, the oscillations did not differ between male and female mice, nor do they differ between mice that underwent a chronic stress paradigm and those in the control group. After the acute administration of a selective serotonin reuptake inhibitor, we observed a shift in the frequency of the oscillations, leading us to hypothesize that the newly observed fluctuations were transporter regulated. Finally, we optimized the experimental parameters of the FSCAV to measure at a higher temporal resolution and found more pronounced shifts in the oscillation frequency, along with a decreased oscillation amplitude. We postulate that this work may serve as a potential bridge for studying serotonin/endocrine interactions that occur on the same time scale.

Exploring Perceived Importance of a Novel Emergency Food Program during COVID-19 and Program Recipient Characteristics.

Following rising unemployment rates and consequent loss of income due to COVID-19, many people have been seeking meal assistance. This study examines the impact of a community-based free meal distribution program during the pandemic in Kentucky, reviewing characteristics of recipients of the program. Demographics, health behaviors, food insecure classification, and rating of importance of the meal program were collected. Qualitative feedback on the impact of the program was collected via open response. Of the 92 participants using the meal service, the cohort was female, Black, 43 years of age (43.5 ± 15.0 years), with a household income under 30,000 USD before COVID, decreased income since COVID, and were food insecure. Recipients rated the importance of the service as 8.7 ± 1.8 (of 10), and those with children indicated the importance as 4.2 ± 1.1 (of 5). Qualitative data on program importance highlighted four response categories including "changed habits", "mental wellbeing", "provided resources", and "other". In response to the COVID-19 pandemic, many individuals have struggled. Meal assistance programs are a fundamental asset in the community that have seen marketed demand since COVID-19. Collaboration with, and evaluation of, meal assistance programs can be valuable for continued programmatic funding support.