A Spacetime Odyssey of Neural Progenitors to Generate Neuronal Diversity / 神经科学通报·英文版

To understand how the nervous system develops from a small pool of progenitors during early embryonic development, it is fundamentally important to identify the diversity of neuronal subtypes, decode the origin of neuronal diversity, and uncover the principles governing neuronal specification across different regions. Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed, leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge. In this review, we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes, including predetermined, stochastic, and cascade diversifying models, and elaborate how these strategies are implemented in distinct regions such as the neocortex, spinal cord, retina, and hypothalamus. Importantly, the identity of neural progenitors is defined by their spatial position and temporal patterning factors, and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes. Microenvironmental cues, spontaneous activity, and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions. The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy, as well as understanding the organization of functional neural circuits and the evolution of the nervous system.

Effect of occupational stress on menses and sex hormones of female knitting workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effect of occupational stress on menses and sex hormones.</p><p><b>METHODS</b>415 female knitting workers were investigated using the generic job stress questionnaire. Their venous blood were collected and the six sex hormones were detected by using radio-immune method. The different rate of abnormal menses and sex hormones level between different stress degree groups were analyzed.</p><p><b>RESULTS</b>The abnormal rate of menses, menstrual blood volume, menstrual cycle, menstrual period was 36.24%, 19.80%, 14.43%, 11.41% respectively. The prevalence rate of dysmenorrheal and premenstrual syndrome was 1.01% and 29.19% respectively. The more depression, the higher menses disorders in non-intrauterine device (IUD) group. The more job demands, the higher daily stress in IUD group while the longer work time, the more abnormal menstrual period in two groups. More physical symptoms and deeper depression in non-IUD group were related to higher abnormal rate of menstrual blood volume. The level of blood E2 was lower in the group of prolonged work-time than that of in normal work-time group. The increasing FSH level and decreasing T level was associated with higher job demands. Multiple factor analysis showed that physical symptom, control of resource and negative life affairs were the risk factors of menses disorder; The physical symptom was the risk factor of menstrual blood volume; More physical symptoms, less positive feeling and shift were the risk factors of premenstrual syndrome; Less positive feeling was the risk factor of menstrual cycle; Prolonged daily work-time was the risk factor of menstrual period.</p><p><b>CONCLUSION</b>Higher stress degree can lead to higher FSH and E2 and lower T level,and induce menses disorder.</p>

Wnt signalling pathway regulates the growth and several phenotypes of Rat-1 cells / 生理学报

The Wnt signaling pathway is thought to be functionally conserved in vertebrates and invertebrates and plays an important role during the embryonic and postembryonic development. Recent studies indicated that this pathway may be also involved in the controlled proliferation and migration of some kinds of fibroblasts during the wound healing process. To verify this assumption in vitro, we chose Rat-1, a kind of rat fibroblasts to investigate the regulation of Wnt signaling pathway to the growth and changes of several phenotypes of this kind of cells. Full length Wnt-3a cDNA was inserted in pcDNA 3.1 vector to construct the Wnt-3a mammalian expression vector, which was stably transfected into Rat-1 cells, and then to establish a cell model in which Wnt signaling pathway was constantly activated. When Wnt signaling pathway was activated constantly, Rat-1 cells exhibited morphological changes: grew more densely as a monolayer, adopted an elongated and refractile appearance, forming cord-like bundles lined up in a uniform direction. The results of MTT assay and FCM analysis indicated that more Rat-1/Wnt-3a cells entered into G(2) phase and the proliferation rate of the Rat-1/ Wnt-3a cells increased significantly compared to the non-transfected cells. Though the migration of Rat-1/Wnt-3a cells increased slightly by the method of Transwell migration assay, there was no statistic significance compared to the non-transfected cells. The result of in vitro scrape wound healing assay showed that for Rat-1/Wnt-3a cells the time course of wound healing decreased significantly. It is therefore concluded that the activation of Wnt signaling pathway can regulate some of the phenotypes of Rat-1 cells, facilitate cell proliferation and promote the scrape wound healing in vitro.