ß-Adrenergic Signaling Promotes Morphological Maturation of Astrocytes in Female Mice.

Astrocytes play essential roles in the developing nervous system, including supporting synapse function. These astrocyte support functions emerge coincident with brain maturation and may be tailored in a region-specific manner. For example, gray matter astrocytes have elaborate synapse-associated processes and are morphologically and molecularly distinct from white matter astrocytes. This raises the question of whether there are unique environmental cues that promote gray matter astrocyte identity and synaptogenic function. We previously identified adrenergic receptors as preferentially enriched in developing gray versus white matter astrocytes, suggesting that noradrenergic signaling could be a cue that promotes the functional maturation of gray matter astrocytes. We first characterized noradrenergic projections during postnatal brain development in mouse and human, finding that process density was higher in the gray matter and increased concurrently with astrocyte maturation. RNA sequencing revealed that astrocytes in both species expressed α- and ß-adrenergic receptors. We found that stimulation of ß-adrenergic receptors increased primary branching of rodent astrocytes in vitro Conversely, astrocyte-conditional knockout of the ß1-adrenergic receptor reduced the size of gray matter astrocytes and led to dysregulated sensorimotor integration in female mice. These studies suggest that adrenergic signaling to developing astrocytes impacts their morphology and has implications for adult behavior, particularly in female animals. More broadly, they demonstrate a mechanism through which environmental cues impact astrocyte development. Given the key roles of norepinephrine in brain states, such as arousal, stress, and learning, these findings could prompt further inquiry into how developmental stressors impact astrocyte development and adult brain function.SIGNIFICANCE STATEMENT This study demonstrates a role for noradrenergic signaling in the development of gray matter astrocytes. We provide new evidence that the ß1-adrenergic receptor is robustly expressed by both mouse and human astrocytes, and that conditional KO of the ß1-adrenergic receptor from female mouse astrocytes impairs gray matter astrocyte maturation. Moreover, female conditional KO mice exhibit behavioral deficits in two paradigms that test sensorimotor function. Given the emerging interest in moving beyond RNA sequencing to probe specific pathways that underlie astrocyte heterogeneity, this study provides a foundation for future investigation into the effect of noradrenergic signaling on astrocyte functions in conditions where noradrenergic signaling is altered, such as stress, arousal, and learning.

Examining Use and Effectiveness of Teletherapy for Patients with Dysphonia.

OBJECTIVE(S)/HYPOTHESIS: Virtual therapy (teletherapy) for patients with dysphonia has become ubiquitous in the COVID-19 era. However, barriers to widespread implementation are evident, including unpredictable insurance coverage attributed to limited evidence supporting this approach. In our single-institution cohort, our objective was to show strong evidence for use and effectiveness of teletherapy for patients with dysphonia. STUDY DESIGN: Single institution, retrospective cohort study. MATERIAL AND METHODS: This was an analysis of all patients referred for speech therapy with dysphonia as primary diagnosis from 4/1/2020 to 7/1/2021 and in whom all therapy sessions were delivered in a teletherapy format. We collated and analyzed demographics and clinical characteristics and adherence to the teletherapy program. We assessed changes in perceptual assessments and vocal capabilities (GRBAS, MPT), patient-reported outcomes (V-RQOL), and metrics of session outcomes (complexity of vocal tasks, carry-over of target voice) pre- and post-teletherapy using student's t test and chi-square test. RESULTS: Our cohort included 234 patients (mean [SD] age 52 [20] years) residing a mean (SD) distance of 51.3 (67.1) miles from our institution. The most common referral diagnosis was muscle tension dysphonia (n = 145, 62.0% patients). Patients attended a mean (SD) of 4.2 (3.0) sessions; 68.0% (n = 159) of patients completed four or more sessions and/or were deemed appropriate for discharge from teletherapy program. Statistically significant improvements were seen in complexity and consistency of vocal tasks with consistent gains in carry-over of target voice for isolated tasks and connected speech. CONCLUSIONS: Teletherapy is a versatile and effective approach for treatment of patients with dysphonia of varying age, geography, and diagnoses.

Location, Location, Location: Transcriptional Control of Astrocyte Heterogeneity.

Huang et al. have found that deletion of astrocyte lineage-specifying transcription factor NFIA from mature astrocytes alters astrocyte morphology, molecular identity, and synaptic-support capacity in a region-specific manner. We discuss the implications of these findings in light of emerging roles for astrocytes in immune cell crosstalk.

A conserved morphogenetic mechanism for epidermal ensheathment of nociceptive sensory neurites.

Interactions between epithelial cells and neurons influence a range of sensory modalities including taste, touch, and smell. Vertebrate and invertebrate epidermal cells ensheath peripheral arbors of somatosensory neurons, including nociceptors, yet the developmental origins and functional roles of this ensheathment are largely unknown. Here, we describe an evolutionarily conserved morphogenetic mechanism for epidermal ensheathment of somatosensory neurites. We found that somatosensory neurons in Drosophila and zebrafish induce formation of epidermal sheaths, which wrap neurites of different types of neurons to different extents. Neurites induce formation of plasma membrane phosphatidylinositol 4,5-bisphosphate microdomains at nascent sheaths, followed by a filamentous actin network, and recruitment of junctional proteins that likely form autotypic junctions to seal sheaths. Finally, blocking epidermal sheath formation destabilized dendrite branches and reduced nociceptive sensitivity in Drosophila. Epidermal somatosensory neurite ensheathment is thus a deeply conserved cellular process that contributes to the morphogenesis and function of nociceptive sensory neurons.

Increased oceanic microplastic debris enhances oviposition in an endemic pelagic insect.

Plastic pollution in the form of small particles (diameter less than 5 mm)--termed 'microplastic'--has been observed in many parts of the world ocean. They are known to interact with biota on the individual level, e.g. through ingestion, but their population-level impacts are largely unknown. One potential mechanism for microplastic-induced alteration of pelagic ecosystems is through the introduction of hard-substrate habitat to ecosystems where it is naturally rare. Here, we show that microplastic concentrations in the North Pacific Subtropical Gyre (NPSG) have increased by two orders of magnitude in the past four decades, and that this increase has released the pelagic insect Halobates sericeus from substrate limitation for oviposition. High concentrations of microplastic in the NPSG resulted in a positive correlation between H. sericeus and microplastic, and an overall increase in H. sericeus egg densities. Predation on H. sericeus eggs and recent hatchlings may facilitate the transfer of energy between pelagic- and substrate-associated assemblages. The dynamics of hard-substrate-associated organisms may be important to understanding the ecological impacts of oceanic microplastic pollution.