Somatostatin Serves a Modulatory Role in the Mouse Olfactory Bulb: Neuroanatomical and Behavioral Evidence

Somatostatin (SOM) and somatostatin receptors (SSTR1–4) are present in all olfactory structures, including the olfactory bulb (OB), where SOM modulates physiological gamma rhythms and olfactory discrimination responses. In this work, histological, viral tracing and transgenic approaches were used to characterize SOM cellular targets in the murine OB. We demonstrate that SOM targets all levels of mitral dendritic processes in the OB with somatostatin receptor 2 (SSTR2) detected in the dendrites of previously uncharacterized mitral-like cells. We show that inhibitory interneurons of the glomerular layer (GL) express SSTR4 while SSTR3 is confined to the granule cell layer (GCL). Furthermore, SOM cells in the OB receive synaptic inputs from olfactory cortical afferents. Behavioral studies demonstrate that genetic deletion of SSTR4, SSTR2 or SOM differentially affects olfactory performance. SOM or SSTR4 deletion have no major effect on olfactory behavioral performances while SSTR2 deletion impacts olfactory detection and discrimination behaviors. Altogether, these results describe novel anatomical and behavioral contributions of SOM, SSTR2 and SSTR4 receptors in olfactory processing

Loss of VGLUT1 and VGLUT2 in the prefrontal cortex is correlated with cognitive decline in Alzheimer disease.

International audienceSeveral lines of evidence suggest that the glutamatergic system is severely impaired in Alzheimer disease (AD). Here, we assessed the status of glutamatergic terminals in AD using the first available specific markers, the vesicular glutamate transporters VGLUT1 and VGLUT2. We quantified VGLUT1 and VGLUT2 in the prefrontal dorsolateral cortex (Brodmann area 9) of controls and AD patients using specific antiserums. A dramatic decrease in VGLUT1 and VGLUT2 was observed in AD using Western blot. Similar decreases were observed in an independent group of subjects using immunoautoradiography. The VGLUT1 reduction was highly correlated with the degree of cognitive impairment, assessed with the clinical dementia rating (CDR) score. A significant albeit weaker correlation was also observed with VGLUT2. These findings provide evidence indicating that glutamatergic systems are severely impaired in the A9 region of AD patients and that this impairment is strongly correlated with the progression of cognitive decline. Our results suggest that VGLUT1 expression in the prefrontal cortex could be used as a valuable neurochemical marker of dementia in AD

Quality of Beverage Intake and Cardiometabolic and Kidney Outcomes: Insights From the STANISLAS Cohort

Background and Aims: Beverages are an important aspect of diet, and their quality can possibly affect health. The Healthy Beverage Index (HBI) has been developed to take into account these effects. This study aimed to highlight the relationships between health and beverage quality by assessing the association of the HBI and its components with kidney and cardiometabolic (CM) outcomes in an initially healthy population-based familial cohort. Methods: This study included 1,271 participants from the STANISLAS cohort. The HBI, which includes 10 components of habitual beverage consumption, was calculated. Associations of the HBI and its components with estimated glomerular filtration rate (eGFR), albuminuria, hypertriglyceridemic waist (HTG waist), metabolic syndrome (MetS), carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT), and left ventricular mass (LV mass) were analyzed using multivariable linear or logistic regression models. Results: The median HBI score was 89.7 (78.6–95) out of 100 points. While the overall HBI score was not significantly associated with any of the studied outcomes, individual HBI components were found differently associated with the outcomes. cfPWV and cIMT were lower in participants who did not meet the full-fat milk criteria (p = 0.03 and 0.001, respectively). In men, higher cfPWV was observed for the “low Fat milk” (p = 0.06) and “alcohol” (p = 0.03) non-adherence criteria. Odds of HTG waist were higher with the non-adherence to sugar-sweetened beverages criteria (p < 0.001). eGFR was marginally higher with non-adherence to the coffee/tea criteria (p = 0.047). Conclusions: In this initially healthy population, HBI components were differently associated with kidney and cardiometabolic outcomes, despite a good overall HBI score. Our results highlight specific impacts of different beverage types and suggest that beverages could have an impact on kidney and cardiometabolic health

Histone deacetylase 9 promotes endothelial to mesenchymal transition and an unfavorable atherosclerotic plaque phenotype

Endothelial-mesenchymal transition (EndMT) is associated with various cardiovascular diseases and in particular with atherosclerosis and plaque instability. However, the molecular pathways that govern EndMT are poorly defined. Specifically, the role of epigenetic factors and histone deacetylases (HDACs) in controlling EndMT and the atherosclerotic plaque phenotype remains unclear. Here, we identified histone deacetylation, specifically that mediated by HDAC9 (a class IIa HDAC), as playing an important role in both EndMT and atherosclerosis. Using in vitro models, we found class IIa HDAC inhibition sustained the expression of endothelial proteins and mitigated the increase in mesenchymal proteins, effectively blocking EndMT. Similarly, ex vivo genetic knockout of Hdac9 in endothelial cells prevented EndMT and preserved a more endothelial-like phenotype. In vivo, atherosclerosis-prone mice with endothelial-specific Hdac9 knockout showed reduced EndMT and significantly reduced plaque area. Furthermore, these mice displayed a more favorable plaque phenotype, with reduced plaque lipid content and increased fibrous cap thickness. Together, these findings indicate that HDAC9 contributes to vascular pathology by promoting EndMT. Our study provides evidence for a pathological link among EndMT, HDAC9, and atherosclerosis and suggests that targeting of HDAC9 may be beneficial for plaque stabilization or slowing the progression of atherosclerotic disease

A (1994) Immunohistochemical localization of L-dopa and aromatic L-amino acid-decarboxylase in the rat retina. Invest Ophthalmol Vis Sci 35(7): 2906–2915

Purpose. The purpose of this study was threefold: to determine if some catecholaminergic amacrine cells of the rat retina use L-DOPA as their neurotransmitter, especially the small (2CA) cells that are immunoreactive to tyrosine hydroxylase but not to dopamine; to understand better the possible existence of serotoninergic cells in the rat retina; and to clarify the role of serotonin in the metabolism of melatonin. Methods. Immunohistochemistry using antibodies against tyrosine hydroxylase (TH), L-DOPA, aromatic L-amino acid decarboxylase (AADC), dopamine (DA), and tyramine in rat retinal wholemounts, serial sections, and various combinations of double labeling. Results. Paired wholemounts immunoreacted with anti-TH/AADC antibodies did not show a significant difference in densities of TH+ and AADC+ amacrine cells. All the TH+ cells exhibited AADC immunoreactivity. There were no AADC-immunoreactive cells lacking TH. A few TH+ cells exhibited L-DOPA immunoreactivity; they also contained AADC. The inner segments of photoreceptor cells were labeled by the anti-AADC antibody. The antibody to tyramine did not label any cells in the rat retina. Conclusions. L-DOPA can be excluded as a candidate active substance for the small TH+ amacrine cells that do not exhibit DA-immunoreactivity. The L-DOPA-immunoreactivity restricted to a small number of large TH+ amacrine cells probably does not represent an end product. Tyramine also does not appear to constitute a neurotransmitter in the rat retina. We confirm that there are no serotonin-synthesizing amacrine cells in the rat retina. The localization of AADC-immunoreactivity in the photoreceptor cell inner segments is possibly related to the biosynthetic pathway of melatonin from 5-hydroxytryptophan. Invest Ophthalmol Vis Sci

Appréhender les catégories zoologiques dans les sociétés du passé

Ce volume thématique fait suite au colloque « Appréhender les catégories zoologiques dans les sociétés du passé », tenu en mars 2019 à Paris et qui a réuni une cinquantaine d’historiens, philosophes et scientifiques autour d’un questionnement épistémologique sur les sources et les méthodes permettant d’appréhender les catégorisations des animaux dans les sociétés anciennes. La richesse de ce colloque, et du volume en résultant, tient tout d’abord à la variété des sociétés évoquées, préhistoriques, antiques ou médiévales mais aussi européennes, asiatiques ou africaines. Elle tient également à une démarche comparatiste permettant de confronter les problèmes méthodologiques communs et d’explorer la diversité des sources qu’elles soient lexicales, iconographiques ou archéologiques

Appréhender les catégories zoologiques en anthropologie historique: enjeux méthodologiques et épistémologiques

Brémont, Axelle, Boudes, Yoan, Thuault, Simon, Saad, Meyssa Ben (2020): Appréhender les catégories zoologiques en anthropologie historique: enjeux méthodologiques et épistémologiques. Anthropozoologica 55 (5): 71-93, DOI: 10.5252/anthropozoologica2020v55a