Neurogenesis in the central olfactory pathway of adult decapod crustaceans: development of the neurogenic niche in the brains of procambarid crayfish

<p>Abstract</p> <p>Background</p> <p>In the decapod crustacean brain, neurogenesis persists throughout the animal's life. After embryogenesis, the central olfactory pathway integrates newborn olfactory local and projection interneurons that replace old neurons or expand the existing population. In crayfish, these neurons are the descendants of precursor cells residing in a neurogenic niche. In this paper, the development of the niche was documented by monitoring proliferating cells with S-phase-specific markers combined with immunohistochemical, dye-injection and pulse-chase experiments.</p> <p>Results</p> <p>Between the end of embryogenesis and throughout the first post-embryonic stage (POI), a defined transverse band of mitotically active cells (which we will term 'the deutocerebral proliferative system' (DPS) appears. Just prior to hatching and in parallel with the formation of the DPS, the anlagen of the niche appears, closely associated with the vasculature. When the hatchling molts to the second post-embryonic stage (POII), the DPS differentiates into the lateral (LPZ) and medial (MPZ) proliferative zones. The LPZ and MPZ are characterized by a high number of mitotically active cells from the beginning of post-embryonic life; in contrast, the developing niche contains only very few dividing cells, a characteristic that persists in the adult organism.</p> <p>Conclusions</p> <p>Our data suggest that the LPZ and MPZ are largely responsible for the production of new neurons in the early post-embryonic stages, and that the neurogenic niche in the beginning plays a subordinate role. However, as the neuroblasts in the proliferation zones disappear during early post-embryonic life, the neuronal precursors in the niche gradually become the dominant and only mechanism for the generation of new neurons in the adult brain.</p

Healthcare Service Quality Evaluation in a Community-Oriented Primary Care Center, Italy

Community-oriented primary care (COPC) is an inclusive healthcare approach that combines individual care with a population-based outlook, striving to offer effective and equitable services. This study concentrates on assessing the perceived quality of a "Casa della Comunita" (CdC) implemented by the Romagna Local Health Authority, which embraces the COPC model. Through the examination of user experiences, the study aims to comprehend the influence of the CdC's care delivery model on the community's perception of service quality. From 13-18 March 2023, paper questionnaires were distributed by trained healthcare professionals and volunteers. The cross-sectional study enrolled participants aged 18 or older, capable of understanding written Italian, and willing to take part voluntarily. A total of 741 questionnaires were collected, resulting in an overall acceptance rate of 85.6%. Among the respondents, 37.9% were female, with an average age of 55.4 &amp; PLUSMN; 16.2 years. While the respondents generally held a positive view of the quality, the results displayed varying levels of satisfaction across the different areas. Multivariate analysis revealed significant associations between factors such as gender, employment status, financial resources, education level, and distance from the healthcare center with the perceived quality of the facility in terms of accessibility, environment, staff, continuity of care, and overall satisfaction. The study yielded valuable insights, identifying strengths and areas for improvement and underscoring the importance of ongoing monitoring studies to enhance patient satisfaction continuously

Neurogenesis in the brain of the Marbled crayfish

The main aim of the project was to study the formation of the main brain scaffold and the mechanisms underlying this process. The brain forms during embryogenesis from an initial thin layer of cells (neuroectoderm) that unfolds into a three dimensional complex structure. This process involves both an intense mitotic activity of progenitor cells (neuroblasts) and a series of morphogenetic movements that lead to a mature and functioning structure of the brain. Analyses were based on immunohistochemical techniques, use of proliferation markers (e.g. 5-bromo-2-deoxyuridine and 5-ethynyl-2’-deoxyuridine) and confocal laser-scan microscopy. Moreover, the use of a specific monoclonal antibody against the protein expressed by engrailed (a segment polarity gene) identified single neuronal cells that were compared with data available for Insecta. In this way, both information on the neurobiology of the Marbled crayfish and on its phylogeny were acquired. One important feature of the crayfish brain is the high plasticity that it shows not only during embryogenesis but throughout its life span. The brain in fact does not stop to develop and after embryogenesis the central olfactory pathway receives newly born olfactory local interneurons and projection neurons that replace old neurons or simply are added to the previous neuronal population. These neurons are provided by a specific post-embryonic structure, the neurogenic niche. By monitoring the activity of NBs, it was possible to discover when and how the niche starts forming and functioning. The topic of adult neurogenesis is a fascinating field of research which involves stem cells biology and regulatory mechanisms that are just now started to be explored. This challenging field of research holds many future perspectives, because some of the main characteristics of the adult neurogenesis in crustaceans are shared with vertebrates, in particular with mammals