University of Bordeaux

About: University of Bordeaux is a education organization based out in Bordeaux, France. It is known for research contribution in the topics: Population & Laser. The organization has 28811 authors who have published 55536 publications receiving 1619635 citations. The organization is also known as: UB.

D1 and D2 receptor gene expression in the rat frontal cortex: cellular localization in different classes of efferent neurons.

Abstract: The dopaminergic input to the frontal cortex has an important role in motor and cognitive functions. These effects are mediated by dopamine receptors both of type D1 and of type D2, although the neural circuits involved are not completely understood. We used in situ hybridization to determine the cellular localization of D1 and D2 receptor mRNAs in the rat frontal cortex. Retrograde tracing was used in the same animals to identify the main cortical efferent populations. Fluorogold was injected into the different cortical targets of the frontal cortex and sections were hybridized with D1 and D2 35S-labelled cRNA probes. D1 and D2 mRNA-containing neurons were present in all the cortical areas investigated, with greater expression in the medial prefrontal, insular and cingulate cortexes and lower expression in the motor and parietal cortexes. Neurons containing D1 mRNA were most abundant in layer VIb; they were also present in layers VIa and V of all cortical layers and in layer II of the medial prefrontal, cingulate and insular areas. Double labelling with fluorogold demonstrated that D1 mRNA was present in corticocortical, corticothalamic and corticostriatal neurons. Neurons containing D2 mRNA were essentially restricted to layer V, but only in corticostriatal and corticocortical neurons. Neither D1 nor D2 mRNA was found in corticospinal or corticopontine neurons. The present results demonstrate that D1 and D2 receptor genes are expressed in efferent cortical populations, with higher expression for D1. In spite of an overlap in some cortical layers, the expression of D1 and D2 receptor genes is specific for different categories of pyramidal neurons.

The Impact of Climate Change on Viticulture and Wine Quality

Abstract: Climate change is a major challenge in wine production. Temperatures are increasing worldwide, and most regions are exposed to water deficits more frequently. Higher temperatures trigger advanced phenology. This shifts the ripening phase to warmer periods in the summer, which will affect grape composition, in particular with respect to aroma compounds. Increased water stress reduces yields and modifies fruit composition. The frequency of extreme climatic events (hail, flooding) is likely to increase. Depending on the region and the amount of change, this may have positive or negative implications on wine quality. Adaptation strategies are needed to continue to produce high-quality wines and to preserve their typicity according to their origin in a changing climate. The choice of plant material is a valuable resource to implement these strategies. (JEL Classifications: Q13, Q54)

Phenotypical characterization of the rat striatal neurons expressing muscarinic receptor genes

Abstract: Neurons expressing the m1, m2, and m4 muscarinic receptor genes in the adult rat striatum were identified and characterized by using several in situ hybridization and immunohistochemical procedures. Combined in situ hybridization for the simultaneous detection of two mRNAs in the same section or in adjacent sections as well as in situ hybridization and immunohistochemistry on adjacent sections permitted us to identify the neurons containing m1, m2, or m4 receptor mRNA. Our observations demonstrate that m1, m2, and m4 receptor genes are expressed in one or several phenotypically distinct neuronal populations. The m1 receptor gene was the most widely expressed (85% of the striatal neurons). Most cholinergic neurons (80% or more) contain m1, m2, and m4 receptor mRNAs. Almost all the substance P neurons contain m1 and m4 receptor mRNA. All enkephalinergic neurons contained m1 receptor mRNA, but only 39% contained m4 receptor mRNA. Most somatostatin and neurotensin neurons expressed the m1 receptor gene, but only a few (15% and 9%, respectively) contained m4 receptor mRNA. The present study offers anatomical evidence that ACh may act directly in complex ways on the main neuronal populations of the striatum through muscarinic receptors. The m1, m2, and m4 receptors may act as autoreceptors to control ACh release and possibly other parameters of ACh neurons. On the other hand, the m1 and m4 receptors may act as heteroreceptors in cholinoceptive efferent neurons (enkephalin and substance P neurons) and other neurons (somatostatin/neuropeptide Y and neurotensin neurons). The presence of m4 receptor mRNA in only parts of the enkephalin, somatostatin, and neurotensin neuronal populations indicates that muscarinic receptor gene expression contributes to the functional and anatomical heterogeneity of the striatum that may relate to higher order of organization, including patch-matrix compartmentalization. The wide expression of m1 and m4 receptor genes in the striatum suggests that ACh may directly influence neurotransmitter release and synthesis in striatal efferent and intrinsic neurons. Our results imply that the specific pattern of expression of the muscarinic receptor genes mediates direct effects of ACh on activities and functions of chemically and topologically defined striatal neuronal populations. Since the expression of muscarinic receptors occurred in the three main neuronal populations of the striatum, namely ACh, enkephalins, and substance P neurons that also express dopamine receptors, it is highly probable that ACh and dopamine may act together at the single-cell level to influence striatal functions.