Just because a rural school system has internet doesn’t mean everyone can afford it. That’s why James Barrett delivers paper work packets, along with meals, to his students during the COVID-19 crisis.

Districts that can screen, interview, and select candidates virtually will have less disruption to their hiring, despite how coronavirus is upending every aspect of school operations.

About a dozen teachers running for state legislative seats gathered with their supporters in Tulsa for a watch party on election night. The results were better for some than others.

Math teachers share advice for making remote instruction work.

A K-8 charter school has opened in Livingston, Ala., that is making history.

A bill approved in both houses of the California legislature would allow certified teachers six paid weeks of maternity leave.

The firing of a black staff member for repeating the n-word while telling a black student not to use it underscores how uneasy many districts, schools, and educators are with handling the use of racist language in any context.

Idaho officials asked a U.S. Supreme Court justice to block an injunction that allows a group backing an education ballot initiative to collect electronic signatures because of COVID-19.

The U.S. Supreme Court blocked an injunction that had allowed a group backing an Idaho education spending measure to collect electronic signatures because of the coronavirus pandemic.

Educators who work in personalized learning schools are adjusting instruction for remote, hybrid, and in-person learning.

Resurrecting an old idea about assessing school quality could allow schools to examine a broad range of data on performance and practices and lead to improvement.

Jonathan Lekkerimäki will make his NHL debut when the Vancouver Canucks take on the Calgary Flames on Tuesday night.

Members of 30 different state and national advocacy groups and unions are meeting in Washington, D.C., for the Grassroots Assembly for Child Care and Early Education.

It's possible there could be an eight-way tie atop the SEC standings at the end of the regular season. Then what will the College Football Playoff committee do?

A school leader outlines how research findings on reducing achievement gaps are reflected in practice at her New Mexico school.

One more teacher was elected to state legislature in a closely contested race.

Sharon G. Kujawa
Nov 11, 2009; 29:14077-14085
BehavioralSystemsCognitive

Mahsa Altafi
Oct 23, 2024; 44:e0518242024-e0518242024
Systems/Circuits

Tessa E.S. Charlesworth
Sep 11, 2019; 39:7228-7243
Viewpoints

Jesse J. Langille
Jul 3, 2019; 39:5244-5246
Journal Club

Pietro Mazzoni
Apr 5, 2006; 26:3642-3645
BRIEF COMMUNICATION

During adolescence, cannabis experimentation is common, and its association with interindividual variations in brain maturation well studied. Cellular and molecular underpinnings of these system-level relationships are, however, unclear. We thus conducted a three-step study. First, we exposed adolescent male mice to -9-tetrahydrocannabinol (THC) or a synthetic cannabinoid WIN 55,212-2 (WIN) and assessed differentially expressed genes (DEGs), spine numbers, and dendritic complexity in their frontal cortex. Second, in human (male) adolescents, we examined group differences in cortical thickness in 34 brain regions, using magnetic resonance imaging, between those who experimented with cannabis before age 16 (n = 140) and those who did not (n = 327). Finally, we correlated spatially these group differences with gene expression of human homologs of mouse-identified DEGs. The spatial expression of 13 THC-related human homologs of DEGs correlated with cannabis-related variations in cortical thickness, and virtual histology revealed coexpression patterns of these 13 genes with cell-specific markers of astrocytes, microglia, and a type of pyramidal cells enriched in dendrite-regulating genes. Similarly, the spatial expression of 18 WIN-related human homologs of DEGs correlated with group differences in cortical thickness and showed coexpression patterns with the same three cell types. Gene ontology analysis indicated that 37 THC-related human homologs are enriched in neuron projection development, while 33 WIN-related homologs are enriched in processes associated with learning and memory. In mice, we observed spine loss and lower dendritic complexity in pyramidal cells of THC-exposed animals (vs controls). Experimentation with cannabis during adolescence may influence cortical thickness by impacting glutamatergic synapses and dendritic arborization.

As evidence mounts that the cardiac-sympathetic nervous system reacts to challenging cognitive settings, we ask if these responses are epiphenomenal companions or if there is evidence suggesting a more intertwined role of this system with cognitive function. Healthy male and female human participants performed an approach-avoidance paradigm, trading off monetary reward for painful electric shock, while we recorded simultaneous electroencephalographic and cardiac-sympathetic signals. Participants were reward sensitive but also experienced approach-avoidance "conflict" when the subjective appeal of the reward was near equivalent to the revulsion of the cost. Drift-diffusion model parameters suggested that participants managed conflict in part by integrating larger volumes of evidence into choices (wider decision boundaries). Late alpha-band (neural) dynamics were consistent with widening decision boundaries serving to combat reward sensitivity and spread attention more fairly to all dimensions of available information. Independently, wider boundaries were also associated with cardiac "contractility" (an index of sympathetically mediated positive inotropy). We also saw evidence of conflict-specific "collaboration" between the neural and cardiac-sympathetic signals. In states of high conflict, the alignment (i.e., product) of alpha dynamics and contractility were associated with a further widening of the boundary, independent of either signal's singular association. Cross-trial coherence analyses provided additional evidence that the autonomic systems controlling cardiac-sympathetics might influence the assessment of information streams during conflict by disrupting or overriding reward processing. We conclude that cardiac-sympathetic control might play a critical role, in collaboration with cognitive processes, during the approach-avoidance conflict in humans.

Cochlear hair cells (HCs) sense sound waves and allow us to hear. Loss of HCs will cause irreversible sensorineural hearing loss. It is well known that DNA damage repair plays a critical role in protecting cells in many organs. However, how HCs respond to DNA damage and how defective DNA damage repair contributes to hearing loss remain elusive. In this study, we showed that cisplatin induced DNA damage in outer hair cells (OHCs) and promoted OHC loss, leading to hearing loss in mice of either sex. Cisplatin induced the expression of Brca1, a DNA damage repair factor, in OHCs. Deficiency of Brca1 induced OHC and hearing loss, and further promoted cisplatin-induced DNA damage in OHCs, accelerating OHC loss. This study provides the first in vivo evidence demonstrating that cisplatin mainly induces DNA damage in OHCs and that BRCA1 promotes repair of DNA damage in OHCs and prevents hearing loss. Our findings not only demonstrate that DNA damage–inducing agent generates DNA damage in postmitotic HCs but also suggest that DNA repair factors, like BRCA1, protect postmitotic HCs from DNA damage–induced cell death and hearing loss.

Neural circuits supporting innate behaviors, such as feeding, exploration, and social interaction, intermingle in the lateral hypothalamus (LH). Although previous studies have shown that individual LH neurons change their firing relative to the baseline during one or more behaviors, the firing rate dynamics of LH populations within behavioral episodes and the coordination of behavior-related LH populations remain largely unknown. Here, using unsupervised graph-based clustering of LH neurons firing rate dynamics in freely behaving male mice, we identified distinct populations of cells whose activity corresponds to feeding, specific times during feeding bouts, or other innate behaviors—social interaction and novel object exploration. Feeding-related cells fired together with a higher probability during slow and fast gamma oscillations (30–60 and 60–90 Hz) than during nonrhythmic epochs. In contrast, the cofiring of neurons signaling other behaviors than feeding was overall similar between slow gamma and nonrhythmic epochs but increased during fast gamma oscillations. These results reveal a neural organization of ethological hierarchies in the LH and point to behavior-specific motivational systems, the dysfunction of which may contribute to mental disorders.

It is well established that holding information in working memory (WM) elicits sustained stimulus-specific patterns of neural activity. Nevertheless, here we provide evidence for a distinct class of neural activity that tracks the number of individuated items in working memory, independent of the type of visual features stored. We present two EEG studies of young adults of both sexes that provide robust evidence for a signal tracking the number of individuated representations in working memory, regardless of the specific feature values stored. In Study 1, subjects maintained either colors or orientations across separate blocks in a single session. We found near-perfect generalization of the load signal between these two conditions, despite being able to simultaneously decode which feature had been voluntarily stored. In Study 2, participants attended to two features with very distinct cortical representations: color and motion coherence. We again found evidence for a neural load signal that robustly generalized across these distinct visual features, even though cortically disparate regions process color and motion coherence. Moreover, representational similarity analysis provided converging evidence for a content-independent load signal, while simultaneously showing that unique variance in EEG activity tracked the specific features that were stored. We posit that this load signal reflects a content-independent "pointer" operation that binds objects to the current context while parallel but distinct neural signals represent the features that are stored for each item in memory.

Key event-related potentials (ERPs) of perceptual decision-making such as centroparietal positivity (CPP) elucidate how evidence is accumulated toward a given choice. Furthermore, this accumulation can be impacted by visual target selection signals such as the N2 contralateral (N2c). How these underlying neural mechanisms of perceptual decision-making are influenced by the spatial congruence of distractors relative to target stimuli remains unclear. Here, we used electroencephalography (EEG) in humans of both sexes to investigate the effect of distractor spatial congruency (same vs different hemifield relative to targets) on perceptual decision-making. We confirmed that responses for perceptual decisions were slower for spatially incongruent versus congruent distractors of high salience. Similarly, markers of target selection (N2c peak amplitude) and evidence accumulation (CPP slope) were found to be lower when distractors were spatially incongruent versus congruent. To evaluate the effects of congruency further, we applied drift diffusion modeling to participant responses, which showed that larger amplitudes of both ERPs were correlated with shorter nondecision times when considering the effect of congruency. The modeling also suggested that congruency's effect on behavior occurred prior to and during evidence accumulation when considering the effects of the N2c peak and CPP slope. These findings point to spatially incongruent distractors, relative to congruent distractors, influencing decisions as early as the initial sensory processing phase and then continuing to exert an effect as evidence is accumulated throughout the decision-making process. Overall, our findings highlight how key electrophysiological signals of perceptual decision-making are influenced by the spatial congruence of target and distractor.

In a new book, a curator at England's Natural History Museum describes rare and interesting nests and eggs—from the house sparrow to the village weaver—and the lessons they hold for avian conservation

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Christopher Gray | Smithsonian Magazine’s 2016 American Ingenuity Award Winner for Youth Achievement Christopher Gray is the founder and CEO of Scholly, the groundbreaking web and mobile app that matches current or future college students who need financial support with scholarships that can help them. Scholly has been downloaded 850,000 times and has connected college students with some $50 million in scholarships. Philadelphia-based Gray, an ABC “Shark Tank” winner and recipient of a $100,000 grant from philanthropist Steve Case’s Rise of the Rest competition, sees his digital platform as a 21st-century tool for helping countless young Americans achieve their college dreams without piling on crushing debt.

With millions of men serving in WWII, the nation needed pilots to ferry planes from the factory to the air bases. That’s when Jackie Cochran proposed a novel idea: why not let women fly?

Smithsonian Secretary Wayne Clough offers personal insights on the realities of climate change and the best ways for society to adapt

A curator from the Houston Museum of Natural Science explains how the terra cotta warriors were discovered and what they reveal about China’s Qin dynasty

Mineralogist Bob Hazen talks about what he loves about walking along the coast of the Chesapeake Bay, hunting for fossils and shark teeth hidden in the sand

Fossils found in Colombia indicate that a giant snake may have roamed the earth 60 million years ago