Selective Deletion of Methyl CpG Binding Protein 2 from Parvalbumin Interneurons in the Auditory Cortex Delays the Onset of Maternal Retrieval in Mice.

Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome. MECP2 codes for methyl CpG binding protein 2 (MECP2), a transcriptional regulator that activates genetic programs for experience-dependent plasticity. Many neural and behavioral symptoms of Rett syndrome may result from dysregulated timing and thresholds for plasticity. As a model of adult plasticity, we examine changes to auditory cortex inhibitory circuits in female mice when they are first exposed to pups; this plasticity facilitates behavioral responses to pups emitting distress calls. Brainwide deletion of Mecp2 alters expression of markers associated with GABAergic parvalbumin interneurons (PVins) and impairs the emergence of pup retrieval. We hypothesized that loss of Mecp2 in PVins disproportionately contributes to the phenotype. Here, we find that deletion of Mecp2 from PVins delayed the onset of maternal retrieval behavior and recapitulated the major molecular and neurophysiological features of brainwide deletion of Mecp2 We observed that when PVin-selective mutants were exposed to pups, auditory cortical expression of PVin markers increased relative to that in wild-type littermates. PVin-specific mutants also failed to show the inhibitory auditory cortex plasticity seen in wild-type mice on exposure to pups and their vocalizations. Finally, using an intersectional viral genetic strategy, we demonstrate that postdevelopmental loss of Mecp2 in PVins of the auditory cortex is sufficient to delay onset of maternal retrieval. Our results support a model in which PVins play a central role in adult cortical plasticity and may be particularly impaired by loss of Mecp2 SIGNIFICANCE STATEMENT Rett syndrome is a neurodevelopmental disorder that includes deficits in both communication and the ability to update brain connections and activity during learning (plasticity). This condition is caused by mutations in the gene MECP2 We use a maternal behavioral test in mice requiring both vocal perception and neural plasticity to probe the role of Mecp2 in social and sensory learning. Mecp2 is normally active in all brain cells, but here we remove it from a specific population (parvalbumin neurons). We find that this is sufficient to delay learned behavioral responses to pups and recreates many deficits seen in whole-brain Mecp2 deletion. Our findings suggest that parvalbumin neurons specifically are central to the consequences of loss of Mecp2 activity and yield clues as to possible mechanisms by which Rett syndrome impairs brain function.

Flattening Hierarchical Structures to Empower Women Trainee Leaders on Social Media Teams.

We share our experience empowering women trainees and leadership through a flattened hierarchical social media team structure with supporting evidence from measurable outcomes.

Ten simple rules for running a successful women-in-STEM organization on an academic campus.

The current academic culture facing women in science, technology, engineering, and math (STEM) fields in the United States has sparked the formation of grassroots advocacy groups to empower female scientists in training. However, the impact of these initiatives often goes unmeasured and underappreciated. Our Women in Science and Engineering (WiSE) organization serves postdoctoral researchers, graduate students, and research technicians (trainees) at a private research institute for biological sciences. Here we propose the following guidelines for cultivating a successful women-in-STEM-focused group based upon survey results from our own scientific community as well as the experience of our WiSE group leaders. We hope these recommendations can provide guidance to advocacy groups at other research and academic organizations that wish to strengthen their efforts. Whereas our own group specifically focuses on the underrepresented state of women in science, we hope these guidelines may be adapted and applied to groups that advocate for any minority group within the greater scientific community (i.e., those of gender, race/ethnicity, socioeconomic background, sexual orientation, etc.).

Correction: Documenting Social Media Engagement as Scholarship: A New Model for Assessing Academic Accomplishment for the Health Professions.

[This corrects the article DOI: 10.2196/25070.].

Documenting Social Media Engagement as Scholarship: A New Model for Assessing Academic Accomplishment for the Health Professions.

BACKGROUND: The traditional model of promotion and tenure in the health professions relies heavily on formal scholarship through teaching, research, and service. Institutions consider how much weight to give activities in each of these areas and determine a threshold for advancement. With the emergence of social media, scholars can engage wider audiences in creative ways and have a broader impact. Conventional metrics like the h-index do not account for social media impact. Social media engagement is poorly represented in most curricula vitae (CV) and therefore is undervalued in promotion and tenure reviews. OBJECTIVE: The objective was to develop crowdsourced guidelines for documenting social media scholarship. These guidelines aimed to provide a structure for documenting a scholar's general impact on social media, as well as methods of documenting individual social media contributions exemplifying innovation, education, mentorship, advocacy, and dissemination. METHODS: To create unifying guidelines, we created a crowdsourced process that capitalized on the strengths of social media and generated a case example of successful use of the medium for academic collaboration. The primary author created a draft of the guidelines and then sought input from users on Twitter via a publicly accessible Google Document. There was no limitation on who could provide input and the work was done in a democratic, collaborative fashion. Contributors edited the draft over a period of 1 week (September 12-18, 2020). The primary and secondary authors then revised the draft to make it more concise. The guidelines and manuscript were then distributed to the contributors for edits and adopted by the group. All contributors were given the opportunity to serve as coauthors on the publication and were told upfront that authorship would depend on whether they were able to document the ways in which they met the 4 International Committee of Medical Journal Editors authorship criteria. RESULTS: We developed 2 sets of guidelines: Guidelines for Listing All Social Media Scholarship Under Public Scholarship (in Research/Scholarship Section of CV) and Guidelines for Listing Social Media Scholarship Under Research, Teaching, and Service Sections of CV. Institutions can choose which set fits their existing CV format. CONCLUSIONS: With more uniformity, scholars can better represent the full scope and impact of their work. These guidelines are not intended to dictate how individual institutions should weigh social media contributions within promotion and tenure cases. Instead, by providing an initial set of guidelines, we hope to provide scholars and their institutions with a common format and language to document social media scholarship.

Relations between cortical thickness, serotonin 1A receptor binding, and structural connectivity: A multimodal imaging study.

Serotonin 1A (5-HT1A ) receptors play a direct role in neuronal development, cell proliferation, and dendritic branching. We hypothesized that variability in 5-HT1A binding can affect cortical thickness, and may account for a subtype of major depressive disorder (MDD) in which both are altered. To evaluate this, we measured cortical thickness from structural magnetic resonance imaging (MRI) and 5-HT1A binding by positron emission tomography (PET) in an exploratory study. To examine a range of 5-HT1A binding and cortical thickness values, we recruited 25 healthy controls and 19 patients with MDD. We hypothesized increased 5-HT1A binding in the raphe nucleus (RN) would be negatively associated with cortical thickness due to reduced serotonergic transmission. Contrary to our hypothesis, raphe 5-HT1A binding was positively correlated with cortical thickness in right posterior cingulate cortex (PCC), a region implicated in the default mode network. Cortical thickness was also positively correlated with 5-HT1A in each cortical region. We further hypothesized that the strength of 5-HT1A -cortical thickness correlation depends on the number of axons between the raphe nucleus and each region. To explore this we related 5-HT1A -cortical thickness correlation coefficients to the number of tracts connecting that region and the raphe, as measured by diffusion tensor imaging (DTI) in an independent sample. The 5-HT1A -cortical thickness association correlated significantly with the number of tracts to each region, supporting our hypothesis. We posit a defect in the raphe may affect the PCC within the default mode network in MDD through serotonergic fibers, resulting in increased ruminative processing.

Effects of maternal deprivation and the duration of reunion time on rat pup ultrasonic vocalization responses to isolation: possible implications for human infant studies.

In a paradigm that may serve as a translational model for maternal separation experiences of human infants in neonatal intensive care units, we examined how the duration of reunion with the dam influenced the phenomenon of maternal potentiation of ultrasonic vocalizations, in which isolated rat pups increase rates of vocalization following brief interactions with dams. We report that maternal potentiation in 12-13 day-old rats did not occur after reunions with their anesthetized dam that lasted longer than 15-min. However, after 18 hr maternal separation, isolated pups given reunions with their anesthetized dam increased vocalization rate even with reunions as long as 3 hr. Using a split-cage apparatus that prevented physical contact, the impact of 18 hr separations on maternal potentiation was partially offset by experiencing olfactory and/or auditory stimuli of the mother. These results suggest that maintaining partial maternal sensory exposure during prolonged maternal separation can reduce responses elicited by subsequent maternal separation.

Selective deletion of Methyl CpG binding protein 2 from parvalbumin interneurons in the auditory cortex delays the onset of maternal retrieval in mice.

Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome. MECP2 codes for methyl CpG binding protein 2 (MECP2), a transcriptional regulator that activates genetic programs for experience-dependent plasticity. Many neural and behavioral symptoms of Rett syndrome may result from dysregulated timing and threshold for plasticity. As a model of adult plasticity, we examine changes to auditory cortex inhibitory circuits in female mice when they are first exposed to pups; this plasticity facilitates behavioral responses to pups emitting distress calls. Brain-wide deletion of Mecp2 alters expression of markers associated with GABAergic parvalbumin interneurons (PVin) and impairs the emergence of pup retrieval. We hypothesized that loss of Mecp2 in PVin disproportionately contributes to the phenotype. Here we find that deletion of Mecp2 from PVin delayed the onset of maternal retrieval behavior and recapitulated the major molecular and neurophysiological features of brain-wide deletion of Mecp2 . We observed that when PVin-selective mutants were exposed to pups, auditory cortical expression of PVin markers increased relative to that in wild type littermates. PVin-specific mutants also failed to show the inhibitory auditory cortex plasticity seen in wild type mice upon exposure to pups and their vocalizations. Finally, using an intersectional viral genetic strategy, we demonstrate that post-developmental loss of Mecp2 in PVin of the auditory cortex is sufficient to delay onset of maternal retrieval. Our results support a model in which PVin play a central role in adult cortical plasticity and may be particularly impaired by loss of Mecp2 . SIGNIFICANCE STATEMENT: Rett syndrome is a neurodevelopmental disorder that includes deficits in both communication and the ability to update brain connections and activity during learning ('plasticity'). This condition is caused by mutations in the gene MECP2 . We use a maternal behavioral test in mice requiring both vocal perception and neural plasticity to probe Mecp2' s role in social and sensory learning. Mecp2 is normally active in all brain cells, but here we remove it from a specific population ('parvalbumin neurons'). We find that this is sufficient to delay learned behavioral responses to pups and recreates many deficits seen in whole brain Mecp2 deletion. Our findings suggest that parvalbumin neurons specifically are central to the consequences of loss of Mecp2 activity and yield clues as to possible mechanisms by which Rett syndrome impairs brain function.

Parvalbumin-Positive Interneurons Regulate Cortical Sensory Plasticity in Adulthood and Development Through Shared Mechanisms.

Parvalbumin-positive neurons are the largest class of GABAergic, inhibitory neurons in the central nervous system. In the cortex, these fast-spiking cells provide feedforward and feedback synaptic inhibition onto a diverse set of cell types, including pyramidal cells, other inhibitory interneurons, and themselves. Cortical inhibitory networks broadly, and cortical parvalbumin-expressing interneurons (cPVins) specifically, are crucial for regulating sensory plasticity during both development and adulthood. Here we review the functional properties of cPVins that enable plasticity in the cortex of adult mammals and the influence of cPVins on sensory activity at four spatiotemporal scales. First, cPVins regulate developmental critical periods and adult plasticity through molecular and structural interactions with the extracellular matrix. Second, they activate in precise sequence following feedforward excitation to enforce strict temporal limits in response to the presentation of sensory stimuli. Third, they implement gain control to normalize sensory inputs and compress the dynamic range of output. Fourth, they synchronize broad network activity patterns in response to behavioral events and state changes. Much of the evidence for the contribution of cPVins to plasticity comes from classic models that rely on sensory deprivation methods to probe experience-dependent changes in the brain. We support investigating naturally occurring, adaptive cortical plasticity to study cPVin circuits in an ethologically relevant framework, and discuss recent insights from our work on maternal experience-induced auditory cortical plasticity.

Student-Run Free Clinics Stand at a Critical Junction Between Undergraduate Medical Education, Clinical Care, and Advocacy.

Student-run free clinics (SRFCs) act as primary care providers that bring health care to populations in need and are an important source of undergraduate medical education (UME), guiding trainees through the art of history taking and physical examination. However, they are also social justice and advocacy initiatives-addressing disparity in access to care and educating medical trainees with firsthand exposure to socioeconomic determinants of health as well as language and medical illiteracy barriers. Here, the authors review academic literature examining the impact of SRFCs in their 3 roles: as medical care providers, as components of medical education, and as advocacy organizations. Based on the evidence of that literature and decades of direct SRFC leadership experience, the authors make the case that SRFCs are an undersupported means by which UME institutions contribute to correcting health care disparities and to serving social justice reform.

Cardiac arrest associated with non-toxigenic corynebacterium diphtheria strain: A case report.

Here we document a rare, acute, infection caused by non-toxigenic Corynebacterium diphtheriae and the resulting unique and severe clinical sequelae. Our patient was a young man with no known pre-existing conditions that presented in cardiopulmonary arrest. We contrast this case with prior instances of non-toxigenic C. diphtheriae strain infection in the United States and summarize the literature that suggests systemic infection can result in cardiogenic toxicity. We speculate on a possible missed, pre-existing condition that could have increased this patient's susceptibility to poor clinical outcome.

Artificial grammar learning in tamarins (Saguinus oedipus) in varying stimulus contexts.

The human ability to detect regularities in sound sequences is a fundamental substrate of our language faculty. However, is this an ability exclusive to human language processing, or have we usurped a more general learning mechanism for this purpose, one shared with other species? The current study is an attempt to replicate and extend Hauser, Weiss, and Marcus's (2002) retracted study (2010) of artificial grammar learning in tamarins to determine if tamarins can detect an underlying grammatical structure in a pattern of sounds. Human language consonant-vowel (CV) combinations from Hauser et al.'s original study, newly created tone sequences, and newly created monkey vocalizations made into sequences were used to familiarize tamarins to an AAB or ABB pattern. Tests of novel sounds in each condition were presented that either were consistent with the familiarized pattern or were different from it. Longer looking times toward the sound source (an audio speaker with a specific location in the auditory field) indicated recognition of novelty. Tamarins looked toward the speaker significantly longer with inconsistent human language CV sequences and with inconsistent tone sequences but not when an inconsistent monkey vocalization was presented. Moreover, tamarins showed differential rates of habituation to the different types of sound patterns, with more robust habituation to CV sequences and tone sequences than to monkey call sequences. The implications of these findings for the generality of learning mechanisms for linguistic and nonlinguistic input across species and the importance of testing across various stimuli are discussed. (PsycINFO Database Record

Gestalt principle use in college students, children with autism, toddlers (Homo sapiens), and cotton top tamarins (Saguinus oedipus).

The use of Gestalt principles of proximity, similarity, and closure to recognize objects by configural superiority was examined in college students, low- and high-functioning children with autism, toddlers, and adult cotton top tamarin monkeys. At issue was whether the monkeys showed differences from humans in perceptual processing and whether they showed any similarities with clinical or developmental groups. The method required a pointing response to discriminate an odd item in a 4-item visual display. All subjects were trained to a high accuracy to point to the odd item before being tested with graphic stimuli that differentiated feature changes based on configural superiority. The results were that college students and high-functioning children with autism responded faster and more accurately to trials in which the odd item was easily noticed by the use of Gestalt principles and configural superiority. Toddlers also responded more accurately to the Gestalt trials, but without being faster at making the response. Low-functioning children with autism and tamarins showed no advantage to Gestalt trials but exhibited different processing styles. The implications of these findings to track the evolution of human perception and to develop a primate model for the perceptual deficits of autism are discussed.