Sleep is required to consolidate odor memory and remodel olfactory synapses.

Animals with complex nervous systems demand sleep for memory consolidation and synaptic remodeling. Here, we show that, although the Caenorhabditis elegans nervous system has a limited number of neurons, sleep is necessary for both processes. In addition, it is unclear if, in any system, sleep collaborates with experience to alter synapses between specific neurons and whether this ultimately affects behavior. C. elegans neurons have defined connections and well-described contributions to behavior. We show that spaced odor-training and post-training sleep induce long-term memory. Memory consolidation, but not acquisition, requires a pair of interneurons, the AIYs, which play a role in odor-seeking behavior. In worms that consolidate memory, both sleep and odor conditioning are required to diminish inhibitory synaptic connections between the AWC chemosensory neurons and the AIYs. Thus, we demonstrate in a living organism that sleep is required for events immediately after training that drive memory consolidation and alter synaptic structures.

Ethnoracial Risk Variation Across the Psychosis Continuum in the US: A Systematic Review and Meta-Analysis.

Importance: Studies suggest a higher risk of schizophrenia diagnoses in Black vs White Americans, yet a systematic investigation of disparities that include other ethnoracial groups and multiple outcomes on the psychosis continuum is lacking. Objective: To identify ethnoracial risk variation in the US across 3 psychosis continuum outcomes (ie, schizophrenia and other psychotic disorders, clinical high risk for psychosis [CHR-P], and psychotic symptoms [PSs] and psychotic experiences [PEs]). Data Sources: PubMed, PsycINFO and Embase were searched up to December 2022. Study Selection: Observational studies on ethnoracial differences in risk of 3 psychosis outcomes. Data Extraction and Synthesis: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Using a random-effects model, estimates for ethnoracial differences in schizophrenia and PSs/PEs were pooled and moderation by sampling and setting was determined, along with the assessment of heterogeneity and risk of bias. Main Outcomes and Measures: Risk of schizophrenia and other psychotic disorder, CHR-P, and conversion to psychosis among CHR-P and PSs/PEs. Results: Of 64 studies in the systematic review, 47 were included in the meta-analysis comprising 54 929 people with schizophrenia and 223 097 with data on PSs/PEs. Compared with White individuals, Black individuals had increased risk of schizophrenia (pooled odds ratio [OR], 2.07; 95% CI, 1.64-2.61) and PSs/PEs (pooled standardized mean difference [SMD], 0.10; 95% CI, 0.03-0.16), Latinx individuals had higher risk of PSs/PEs (pooled SMD, 0.15; 95% CI, 0.08-0.22), and individuals classified as other ethnoracial group were at significantly higher risk of schizophrenia than White individuals (pooled OR, 1.81; 95% CI, 1.31-2.50). The results regarding CHR-P studies were mixed and inconsistent. Sensitivity analyses showed elevated odds of schizophrenia in Asian individuals in inpatient settings (pooled OR, 1.84; 95% CI, 1.19-2.84) and increased risk of PEs among Asian compared with White individuals, specifically in college samples (pooled SMD, 0.16; 95% CI, 0.02-0.29). Heterogeneity across studies was high, and there was substantial risk of bias in most studies. Conclusions and Relevance: Findings of this systematic review and meta-analysis revealed widespread ethnoracial risk variation across multiple psychosis outcomes. In addition to diagnostic, measurement, and hospital bias, systemic influences such as structural racism should be considered as drivers of ethnoracial disparities in outcomes across the psychosis continuum in the US.