Long-Term Impact of Early Life Stress on Serotonin Connectivity.

BACKGROUND: Chronic childhood stress is a prominent risk factor for developing affective disorders, yet mechanisms underlying this association remain unclear. Maintenance of optimal serotonin (5-HT) levels during early postnatal development is critical for the maturation of brain circuits. Understanding the long-lasting effects of early life stress (ELS) on serotonin-modulated brain connectivity is crucial to develop treatments for affective disorders arising from childhood stress. METHODS: Using a mouse model of chronic developmental stress, we determined the long-lasting consequences of ELS on 5-HT circuits and behavior in females and males. Using FosTRAP mice, we cross-correlated regional c-Fos density to determine brain-wide functional connectivity of the raphe nucleus. We next performed in vivo fiber photometry to establish ELS-induced deficits in 5-HT dynamics and optogenetics to stimulate 5-HT release to improve behavior. RESULTS: Adult female and male mice exposed to ELS showed heightened anxiety-like behavior. ELS further enhanced susceptibility to acute stress by disrupting the brain-wide functional connectivity of the raphe nucleus and the activity of 5-HT neuron population, in conjunction with increased orbitofrontal cortex (OFC) activity and disrupted 5-HT release in medial OFC. Optogenetic stimulation of 5-HT terminals in the medial OFC elicited an anxiolytic effect in ELS mice in a sex-dependent manner. CONCLUSIONS: These findings suggest a significant disruption in 5-HT-modulated brain connectivity in response to ELS, with implications for sex-dependent vulnerability. The anxiolytic effect of the raphe-medial OFC circuit stimulation has potential implications for developing targeted stimulation-based treatments for affective disorders that arise from early life adversities.

Factors that influence beginning teacher retention during the COVID-19 pandemic: Findings from one Canadian province.

Concern over early career teacher attrition has increased since the onset of COVID-19, but little is known about how the pandemic affected the personal and professional factors that play a role in successful teacher retention in Alberta, Canada. Starting in May 2021, a combination of survey design and focus groups were used to examine beginning teachers' well-being, resiliency, and perceptions on early career teaching and pandemic considerations. Compared to the previous year of data collection administration in 2019-2020, participants reported significantly less positive responses related to professional factors, but in terms of personal factors, participants remained efficacious and resilient. Responses also indicated that beginning teachers were mainly dissatisfied with COVID-19 pandemic circumstances, but not the teaching profession. Therefore, despite facing numerous challenges over the past two years, beginning teachers' passion and commitment to their chosen career appears to remain strong.