Time-course adaptive changes in hippocampal transcriptome and synaptic function induced by simulated microgravity associated with cognition.

Introduction: The investigation of cognitive function in microgravity, both short-term and long-term, remains largely descriptive. And the underlying mechanisms of the changes over time remain unclear. Methods: Behavioral tests, electrophysiological recording, and RNA sequencing were used to observe differences in behavior, synaptic plasticity, and gene expression. Results: Initially, we measured the performance of spatial cognition exposed to long-term simulated microgravity (SM). Both working memory and advanced cognitive abilities were enhanced. Somewhat surprisingly, the synaptic plasticity of the hippocampal CA3-CA1 synapse was impaired. To gain insight into the mechanism of changing regularity over time, transcriptome sequencing in the hippocampus was performed. The analysis identified 20 differentially expressed genes (DEGs) in the hippocampus after short-term modeling, 19 of which were up-regulated. Gene Ontology (GO) analysis showed that these up-regulated genes were mainly enriched in synaptic-related processes, such as Stxbp5l and Epha6. This might be related to the enhancement of working memory performance under short-term SM exposure. Under exposure to long-term SM, 7 DEGs were identified in the hippocampus, all of which were up-regulated and related to oxidative stress and metabolism, such as Depp1 and Lrg1. Compensatory effects occurred with increased modeling time. Discussion: To sum up, our current research indicates that the cognitive function under SM exposure is consistently maintained or potentially even being enhanced over both short and long durations. The underlying mechanisms are intricate and potentially linked to the differential expression of hippocampal-associated genes and alterations in synaptic function, with these effects being time-dependent. The present study will lay the experimental and theoretical foundation of the multi-level mechanism of cognitive function under space flight.

Medial prefrontal cortex and hippocampus in mice differently affected by simulate microgravity and social isolation associated with the alternation of emotional and cognitive functions.

Long-term spaceflight has been proved to cause physical impairments such as motor, cardiovascular and endocrine functions in astronauts. But psychological effects such as mood and social interaction are less well understood. Besides, there are conflicting accounts of their effects on cognitive function. Thus in this study, we exposed mice (18-21 g) to 28-day simulate microgravity and social isolation (SM+SI) and examined its effects on mood, social interaction and cognitive function. We found that four weeks of SM+SI exposure resulted in emotional and specific social barriers, which may be associated with loss of neurons and decreased dendritic spine density in the medial prefrontal cortex. Unexpectedly, SM+SI enhanced the short and long-term cognitive abilities of mice, which may be related to the anti-apoptotic effect of SM+SI regulating the level of apoptotic factors in the hippocampus. These results indicates that SM+SI, as chronic stressor, can induce the body to establish effective coping strategies to enhance individuals' cognitive ability; on the other hand, long-term exposure to SM+SI causes emotional/social barriers. This study further demonstrates SM+SI causes different effects in a brain-region specific manner. Current findings provide a theoretical basis for understanding how SM+SI acts on the brain structure to influence mental health, and may be useful for designing effective prevention for those, including the astronauts, exposed to microgravity.

A new brood-pollination mutualism between Stellera chamaejasme and flower thrips Frankliniella intonsa.

BACKGROUND: Brood pollination mutualism is a special type of plant-pollinator interaction in which adult insects pollinate plants, and the plants provide breeding sites for the insects as a reward. To manifest such a mutualism between Stellera chamaejasme and flower thrips of Frankliniella intonsa, the study tested the mutualistic association of the thrips life cycle with the plant flowering phenology and determined the pollination effectiveness of adult thrips and their relative contribution to the host's fitness by experimental pollinator manipulation. RESULTS: The adult thrips of F. intonsa, along with some long-tongue Lepidoptera, could serve as efficient pollinators of the host S. chamaejasme. The thrips preferentially foraged half-flowering inflorescences of the plants and oviposited in floral tubes. The floral longevity was 11.8 ± 0.55 (mean ± se) days, which might precisely accommodate the thrips life cycle from spawning to prepupation. The exclusion of adult thrips from foraging flowers led to a significant decrease in the fitness (i.e., seed set) of host plants, with a corresponding reduction in thrips fecundity (i.e., larva no.) in the flowers. CONCLUSIONS: The thrips of F. intonsa and the host S. chamaejasme mutualistically interact to contribute to each other's fitness such that the thrips pollinate host plants and, as a reward, the plants provide the insects with brooding sites and food, indicating the coevolution of the thrips life cycle and the reproductive traits (e.g., floral longevity and morphology) of S. chamaejasme.

Willingness and beliefs associated with reporting travel history to high-risk coronavirus disease 2019 epidemic regions among the Chinese public: a cross-sectional study.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) that first occurred in Wuhan, China, is currently spreading throughout China. The majority of infected patients either traveled to Wuhan or came into contact with an infected person from Wuhan. Investigating members of the public with a travel history to Wuhan became the primary focus of the Chinese government's epidemic prevention and control measures, but several instances of withheld histories were uncovered as localized clusters of infections broke out. This study investigated the public's willingness and beliefs associated with reporting travel history to high-risk epidemic regions, to provide effective suggestions and measures for encouraging travel reporting. METHODS: A cross-sectional study was conducted online between February 12 and 19, 2020. Descriptive analysis, chi-squared test, and Fisher's exact test were used to identify socio-demographic factors and beliefs associated with reporting, as well as their impact on the willingness to report on travel history to high-risk epidemic regions. RESULTS: Of the 1344 respondents, 91 (6.77%) expressed an inclination to deliberately withhold travel history. Those who understood the benefits of reporting and the legal consequences for deliberately withholding information, showed greater willingness to report their history (P < 0.05); conversely, those who believed reporting would stigmatize them and feared being quarantined after reporting showed less willingness to report (P < 0.05). CONCLUSIONS: As any incident of withheld history can have unpredictable outcomes, the proportion of people who deliberately withhold information deserves attention. Appropriate public risk communication and public advocacy strategies should be implemented to strengthen the understanding that reporting on travel history facilitates infection screening and prompt treatment, and to decrease the fear of potentially becoming quarantined after reporting. Additionally, social support and policies should be established, and measures should be taken to alleviate stigmatization and discrimination against potential patients and reporters of travel history. Reinforcing the legal accountability of withholding travel history and strengthening systematic community monitoring are the measures that China is currently taking to encourage reporting on travel history to high-risk epidemic regions. These non-pharmaceutical interventions are relevant for countries that are currently facing the spread of the epidemic and those at risk of its potential spread.

Clinical features and risk factors for post-partum depression in a large cohort of Chinese women with recurrent major depressive disorder.

BACKGROUND: Post partum depression (PPD) is relatively common in China but its clinical characteristics and risk factors have not been studied. We set out to investigate whether known risk factors for PPD could be found in Chinese women. METHODS: A case control design was used to determine the impact of known risk factors for PPD in a cohort of 1970 Chinese women with recurrent DSM-IV major depressive disorder (MDD). In a within-case design we examined the risk factors for PPD in patients with recurrent MDD. We compared the clinical features of MDD in cases with PPD to those without MDD. Odds ratios were calculated using logistic and ordinal regression. RESULTS: Lower occupational and educational statuses increased the risk of PPD, as did a history of pre-menstrual symptoms, stressful life events and elevated levels of the personality trait of neuroticism. Patients with PPD and MDD were more likely to experience a comorbid anxiety disorder, had a younger age of onset of MDD, have higher levels of neuroticism and dysthymia. LIMITATIONS: Results obtained in this clinical sample may not be applicable to PPD within the community. Data were obtained retrospectively and we do not know whether the correlations we observe have the same causes as those operating in other populations. CONCLUSIONS: Our results are consistent with the hypothesis that the despite cultural differences between Chinese and Western women, the phenomenology and risk factors for PPD are very similar.

A comparison of melancholic and nonmelancholic recurrent major depression in Han Chinese women.

BACKGROUND: Although the diagnosis of melancholia has had a long history, the validity of the current DSM-IV definition remains contentious. We report here the first detailed comparison of melancholic and nonmelancholic major depression (MD) in a Chinese population examining in particular whether these two forms of MD differ quantitatively or qualitatively. METHODS: DSM-IV criteria for melancholia were applied to 1,970 Han Chinese women with recurrent MD recruited from 53 provincial mental health centers and psychiatric departments of general medical hospitals in 41 cities. Statistical analyses, utilizing Student's t-tests and Pearson's χ(2) , were calculated using SPSS 13.0. RESULTS: Melancholic patients with MD were distinguished from nonmelancholic by being older, having a later age at onset, more episodes of illness and meeting more A criteria. They also had higher levels of neuroticism and rates of lifetime generalized anxiety disorder, panic disorder, and social and agoraphobia. They had significantly lower rates of childhood sexual abuse but did not differ on other stressful life events or rates of MD in their families. DISCUSSION: Consistent with most prior findings in European and US populations, we find that melancholia is a more clinically severe syndrome than nonmelancholic depression with higher rates of comorbidity. The evidence that it is a more "biological" or qualitatively distinct syndrome, however, is mixed.

Age at onset of major depressive disorder in Han Chinese women: relationship with clinical features and family history.

BACKGROUND: Individuals with early-onset depression may be a clinically distinct group with particular symptom patterns, illness course, comorbidity and family history. This question has not been previously investigated in a Han Chinese population. METHODS: We examined the clinical features of 1970 Han Chinese women with DSM-IV major depressive disorder (MDD) between 30 and 60 years of age across China. Analysis of linear, logistic and multiple logistic regression models was used to determine the association between age at onset (AAO) with continuous, binary and discrete characteristic clinical features of MDD. RESULTS: Earlier AAO was associated with more suicidal ideation and attempts and higher neuroticism, but fewer sleep, appetite and weight changes. Patients with an earlier AAO were more likely to suffer a chronic course (longer illness duration, more MDD episodes and longer index episode), increased rates of MDD in their parents and a lower likelihood of marriage. They tend to have higher comorbidity with anxiety disorders (general anxiety disorder, social phobia and agoraphobia) and dysthymia. CONCLUSIONS: Early AAO in MDD may be an index of a more severe, highly comorbid and familial disorder. Our findings indicate that the features of MDD in China are similar to those reported elsewhere in the world.