Contribution of the d-Serine-Dependent Pathway to the Cellular Mechanisms Underlying Cognitive Aging

An association between age-related memory impairments and changes in functional plasticity in the aging brain has been under intense study within the last decade. In this article, we show that an impaired activation of the strychnine-insensitive glycine site of N-methyl-d-aspartate receptors (NMDA-R) by its agonist d-serine contributes to deficits of synaptic plasticity in the hippocampus of memory-impaired aged rats. Supplementation with exogenous d-serine prevents the age-related deficits of isolated NMDA-R-dependent synaptic potentials as well as those of theta-burst-induced long-term potentiation and synaptic depotentiation. Endogenous levels of d-serine are reduced in the hippocampus with aging, that correlates with a weaker expression of serine racemase synthesizing the amino acid. On the contrary, the affinity of d-serine binding to NMDA-R is not affected by aging. These results point to a critical role for the d-serine-dependent pathway in the functional alterations of the brain underlying memory impairment and provide key information in the search for new therapeutic strategies for the treatment of memory deficits in the elderly

P16-37. HIV controllers with weak CD8+ T cell responses maintain a tight control of infection despite carrying infectious viruses

International audienc

The Late Middle Palaeolithic Occupation of Abri du Maras (Layer 1, Neronian, Southeast France): Integrating Lithic Analyses, ZooMS and Radiocarbon Dating to Reconstruct Neanderthal Hunting Behaviour

The exact strategies and technologies underlying Neanderthal hunting events remain open for debate with lithic points being sparse across the European Middle Palaeolithic. An exception is the Neronian entity in southeast France, defined by ventrally retouched Soyons points. This study contextualises one of the largest Neronian assemblages, layer 1 at Abri du Maras. Our lithic analyses focussed on attributes described as indicative of projectile use or hafting to contextualise the morphometric and technological characteristics of the pointed implements at an assemblage level. We found that retouched points were made on a variety of blank types (including Levallois, laminar and discoidal flaking techniques) and ventral retouch is present across different artefact types (including points, scrapers and denticulates). Next, these lithic data were compared to similar typo-technological data recorded on a sample from the recently excavated and well-contextualised point-rich layer 4.1 of Abri du Maras (MIS-3). Zooarchaeology by Mass Spectrometry (ZooMS) was applied to 280 faunal remains from layer 1 and indicated significant proportions of equids, bovids, cervids and reindeer. Carnivore remains and carnivore modifications are absent, while human bone surface modifications are present across a variety of species. Five bones had sufficient collagen for radiocarbon dating but returned dates younger than expected (ca. 41–31 ka cal BP). Finally, we place Abri du Maras layer 1 in its broader regional context and discuss its relation to other Neronian assemblages and more general problematics inherent to studying material from old excavations

A 41,500 year-old decorated ivory pendant from Stajnia Cave (Poland)

Evidence of mobiliary art and body augmentation are associated with the cultural innovations introduced by Homo sapiens at the beginning of the Upper Paleolithic. Here, we report the discovery of the oldest known human-modified punctate ornament, a decorated ivory pendant from the Paleolithic layers at Stajnia Cave in Poland. We describe the features of this unique piece, as well as the stratigraphic context and the details of its chronometric dating. The Stajnia Cave plate is a personal 'jewellery' object that was created 41,500 calendar years ago (directly radiocarbon dated). It is the oldest known of its kind in Eurasia and it establishes a new starting date for a tradition directly connected to the spread of modern Homo sapiens in Europe

Le Genévrier thurifère, espèce partagée au nord et au sud de la Méditerranée

Le 4e colloque sur le Genévrier thurifère (octobre 2011), a été l’occasion de partager les connaissances, les expériences et les avancées scientifiques sur cette espèce partagée au Sud et au Nord de la Méditerranée... Une approche pluridisciplinaire, des sciences humaines et sociales aux sciences biologiques… et médicales a permis de montrer les relations très fortes que cet arbre entretient, depuis des siècles, avec l’Homme, mais aussi la confrontation entre des préoccupations de gestion et des préoccupations de recherche plus fondamentales. Cet article est la synthèse du colloque

Identifying the unidentified fauna enhances insights into hominin subsistence strategies during the Middle to Upper Palaeolithic transition

Understanding Palaeolithic hominin subsistence strategies requires the comprehensive taxonomic identification of faunal remains. The high fragmentation of Late Pleistocene faunal assemblages often prevents proper taxonomic identification based on bone morphology. It has been assumed that the morphologically unidentifiable component of the faunal assemblage would reflect the taxonomic abundances of the morphologically identified portion. In this study, we analyse three faunal datasets covering the Middle to Upper Palaeolithic transition (MUPT) at Bacho Kiro Cave (Bulgaria) and Les Cottés and La Ferrassie (France) with the application of collagen type I peptide mass fingerprinting (ZooMS). Our results emphasise that the fragmented component of Palaeolithic bone assemblages can differ significantly from the morphologically identifiable component. We obtain contrasting identification rates between taxa resulting in an overrepresentation of morphologically identified reindeer (Rangifer tarandus) and an underrepresentation of aurochs/bison (Bos/Bison) and horse/European ass (Equus) at Les Cottés and La Ferrassie. Together with an increase in the relative diversity of the faunal composition, these results have implications for the interpretation of subsistence strategies during a period of possible interaction between Neanderthals and Homo sapiens in Europe. Furthermore, shifts in faunal community composition and in carnivore activity suggest a change in the interaction between humans and carnivores across the MUPT and indicate a possible difference in site use between Neanderthals and Homo sapiens. The combined use of traditional and biomolecular methods allows (zoo)archaeologists to tackle some of the methodological limits commonly faced during the morphological assessment of Palaeolithic bone assemblages

Homo sapiens reached the higher latitudes of Europe by 45,000 years ago

The Middle to Upper Palaeolithic transition in Europe is associated with the regional disappearance of Neanderthals and the spread of Homo sapiens. Late Neanderthals persisted in western Europe several millennia after the occurrence of H. sapiens in eastern Europe1. Local hybridization between the two groups occurred2, but not on all occasions3. Archaeological evidence also indicates the presence of several technocomplexes during this transition, complicating our understanding and the association of behavioural adaptations with specific hominin groups4. One such technocomplex for which the makers are unknown is the Lincombian–Ranisian–Jerzmanowician (LRJ), which has been described in northwestern and central Europe5,6,7,8. Here we present the morphological and proteomic taxonomic identification, mitochondrial DNA analysis and direct radiocarbon dating of human remains directly associated with an LRJ assemblage at the site Ilsenhöhle in Ranis (Germany). These human remains are among the earliest directly dated Upper Palaeolithic H. sapiens remains in Eurasia. We show that early H. sapiens associated with the LRJ were present in central and northwestern Europe long before the extinction of late Neanderthals in southwestern Europe. Our results strengthen the notion of a patchwork of distinct human populations and technocomplexes present in Europe during this transitional period