Astrocytic β2-adrenergic receptors mediate hippocampal long-term memory consolidation.

Emotionally relevant experiences form strong and long-lasting memories by critically engaging the stress hormone/neurotransmitter noradrenaline, which mediates and modulates the consolidation of these memories. Noradrenaline acts through adrenergic receptors (ARs), of which β2-adrenergic receptors (βARs) are of particular importance. The differential anatomical and cellular distribution of βAR subtypes in the brain suggests that they play distinct roles in memory processing, although much about their specific contributions and mechanisms of action remains to be understood. Here we show that astrocytic rather than neuronal β2ARs in the hippocampus play a key role in the consolidation of a fear-based contextual memory. These hippocampal β2ARs, but not β1ARs, are coupled to the training-dependent release of lactate from astrocytes, which is necessary for long-term memory formation and for underlying molecular changes. This key metabolic role of astrocytic β2ARs may represent a novel target mechanism for stress-related psychopathologies and neurodegeneration

Evolution Characteristics for Water Eco-Environment of Baiyangdian Lake with 3S Technologies in the Past 60 Years

Part 1: GIS, GPS, RS and Precision FarmingInternational audienceKeeping water eco-environment health and virtuous circle of lake-wetland, and letting lakes recuperate and reproduce has become a common view all over the world. Although a great deal of research results were obtained, such as lake-wetland ecosystem management and eco-hydrological mechanism of eco-environment evolution, there are few researches about comprehensive analysis on evolution trend and driven mechanism of lake-wetland water eco-environment. Baiyangdian, the biggest grass-type lake-wetland in North China, was chosen as the research object in this paper. Based on the long-term and field observations of water environmental quality and analysis for remote sensing images of water ecological landscape pattern, the evolution trend and driving mechanism for water eco-environment of Baiyangdian in the past 60 years have been studied systematically. The results showed that the average annual water level fluctuated greatly with a decreasing tendency as a whole. During 1974 and 2007, there was a general pattern of land use types, which the emergent plants, water body and cultivated land were the main, and the residential area, forest land, grass land and unused land were distributed as flower arrangement state. During the periods, the water body and emergent plants areas were decreased respectively by 28.7% and 20.8%, while the cultivated land areas were increased by 69.7%. The main pollutants (NH4+-N, CODMn, BOD5, TP, and TN) concentrations in Baiyangdian Lake were changed greatly with spatiotemporal variation and the pollutant concentrations were increased obviously. In the three polluted regions (north zone, south zone, and mixed zone), the north zone was polluted most seriously. The main pollutants concentrations were fluctuated obviously over a year, and the pollution was more serious in summer of normal and dry years, while the pollution was serious at the beginning of summer flood in wet years, and then became less. At last, the evolution trend and driven mechanism of water eco-environment of Baiyangdian was analyzed from three aspects, including typical climate indexes (such as precipitation, evaporation, air temperature, and solar radiation), ecological/environmental hydrology regime in upstream watershed of Baiyangdian, and human activities. It would provide some references to the comprehensive treatment of water eco-environment in Baiyangdian Lakes