Neurotransmitter classification from electron microscopy images at synaptic sites in Drosophila melanogaster.

High-resolution electron microscopy of nervous systems has enabled the reconstruction of synaptic connectomes. However, we do not know the synaptic sign for each connection (i.e., whether a connection is excitatory or inhibitory), which is implied by the released transmitter. We demonstrate that artificial neural networks can predict transmitter types for presynapses from electron micrographs: a network trained to predict six transmitters (acetylcholine, glutamate, GABA, serotonin, dopamine, octopamine) achieves an accuracy of 87% for individual synapses, 94% for neurons, and 91% for known cell types across a D. melanogaster whole brain. We visualize the ultrastructural features used for prediction, discovering subtle but significant differences between transmitter phenotypes. We also analyze transmitter distributions across the brain and find that neurons that develop together largely express only one fast-acting transmitter (acetylcholine, glutamate, or GABA). We hope that our publicly available predictions act as an accelerant for neuroscientific hypothesis generation for the fly.

COVID-19 mRNA vaccines induce robust levels of IgG but limited amounts of IgA within the oronasopharynx of young children.

BACKGROUND: Understanding antibody responses to SARS-CoV-2 vaccination is crucial for refining COVID-19 immunization strategies. Generation of mucosal immune responses, including mucosal IgA, could be of potential benefit to vaccine efficacy, yet limited evidence exists regarding the production of mucosal antibodies following the administration of current mRNA vaccines to young children. METHODS: We measured the levels of antibodies against SARS-CoV-2 from a cohort of children under 5 years of age (N=24) undergoing SARS-CoV-2 mRNA vaccination (serially collected, matched serum and saliva samples) or in a convenience sample of children under 5 years of age presenting to pediatric emergency department (nasal swabs, N=103). Further, we assessed salivary and nasal samples for the ability to induce SARS-CoV-2 spike-mediated neutrophil extracellular traps (NET) formation. RESULTS: Longitudinal analysis of post-vaccine responses in saliva revealed the induction of SARS-CoV-2 specific IgG but not IgA. Similarly, SARS-CoV-2 specific IgA was only observed in nasal samples obtained from previously infected children with or without vaccination, but not in vaccinated children without a history of infection. In addition, oronasopharyngeal samples obtained from children with prior infection were able to trigger enhanced spike-mediated NET formation, and IgA played a key role in driving this process. CONCLUSIONS: Despite the induction of specific IgG in the oronasal mucosa, current intramuscular vaccines have limited ability to generate mucosal IgA in young children. These results confirm the independence of mucosal IgA responses from systemic humoral responses following mRNA vaccination and suggest potential future vaccination strategies for enhancing mucosal protection in this young age group.

Evaluation of Insurance Type as a Proxy for Socioeconomic Status in the Pediatric Emergency Department: A Pilot Study.

STUDY OBJECTIVE: To determine whether insurance status can function as a sufficient proxy for socioeconomic status in emergency medicine research by examining the concordance between insurance status and direct socioeconomic status measures in a sample of pediatric patients. METHODS: We conducted a cross-sectional pilot study of patients aged 5 to 17 years in the emergency department of a quaternary care children's hospital. Socioeconomic status was measured using the highest level of the caregiver's education (low: less than bachelor's degree; high: bachelor's or greater) and previous year household income (low: <$75,000; high: ≥$75,000). We calculated the misclassification rate of insurance status (low: public; high: private) using education and income as reference standards. Results were expressed as percentages with 95% confidence intervals. RESULTS: In total, 300 patients were enrolled (median age 11 years, 44% female). Insurance status misclassified 23% (95% CI 18% to 28%) and 14% (95% CI 10% to 19%) of patients when using caregiver education and income, respectively, as reference standards. CONCLUSIONS: Insurance status misclassified socioeconomic status in up to 23% of pediatric patients, as measured by caregivers' education and income. Emergency medicine studies of pediatric patients using insurance as a covariate to adjust for socioeconomic status may need to consider this misclassification and the resulting potential for bias. These findings require confirmation in larger, more diverse samples, including adult patients.

Undergraduate-level biology students' application of central dogma to understand COVID mRNA vaccines.

The coronavirus disease 2019 (COVID-19) pandemic has underscored the importance of mRNA vaccines. The mechanism for how such vaccines work is related to the core biology topic of the central dogma, which students often misunderstand despite its importance. Therefore, we wanted to know whether students can apply their biology knowledge of central dogma to the real-world issue of how mRNA COVID vaccines work. Accordingly, we asked college biology students of different expertise levels how the COVID vaccine worked. Later, we cued them by telling them the vaccine contains mRNA and asked them what the mRNA does. We used thematic analysis to find common ideas in their responses. In the uncued condition, fewer than half of the students used central dogma-related ideas to explain what was in the vaccine or how the vaccine worked. Inaccurate ideas were present among all groups of biology students, particularly entering biology majors and non-biology majors, including the idea that the COVID vaccines contain a weakened, dead, or variant form of the COVID virus. After students were cued, many more students in all expertise groups expressed central dogma-related themes, showing that students could apply the knowledge of central dogma if prompted. Advanced biology majors were much more likely to state that the vaccines code for a viral protein, indicating their advanced application of central dogma concepts. These results highlight inaccurate ideas common among students and show changes in the ability to apply knowledge with student expertise level, which could inform future interventions to support student learning about vaccines and central dogma.

COVID-19 mRNA vaccines induce robust levels of IgG but limited amounts of IgA within the oronasopharynx of young children.

Background: Understanding antibody responses to SARS-CoV-2 vaccination is crucial for refining COVID-19 immunization strategies. Generation of mucosal immune responses, including mucosal IgA, could be of potential benefit to vaccine efficacy, yet limited evidence exists regarding the production of mucosal antibodies following the administration of current mRNA vaccines to young children. Methods: We measured the levels of antibodies against SARS-CoV-2 from a cohort of children under 5 years of age undergoing SARS-CoV-2 mRNA vaccination (serially collected, matched serum and saliva samples, N=116) or on convenience samples of children under 5 years of age presenting to a pediatric emergency department (nasal swabs, N=103). Further, we assessed salivary and nasal samples for the ability to induce SARS-CoV-2 spike-mediated neutrophil extracellular traps (NET) formation. Results: Longitudinal analysis of post-vaccine responses in saliva revealed the induction of SARS-CoV-2 specific IgG but not IgA. Similarly, SARS-CoV-2 specific IgA was only observed in nasal samples obtained from previously infected children with or without vaccination, but not in vaccinated children without a history of infection. In addition, oronasopharyngeal samples obtained from children with prior infection were able to trigger enhanced spike-mediated NET formation, and IgA played a key role in driving this process. Conclusions: Despite the induction of specific IgG in the oronasal mucosa, current intramuscular vaccines have limited ability to generate mucosal IgA in young children. These results confirm the independence of mucosal IgA responses from systemic humoral responses following mRNA vaccination and suggest potential future vaccination strategies for enhancing mucosal protection in this young age group.