Neuroligins in neurodevelopmental conditions: how mouse models of de novo mutations can help us link synaptic function to social behavior

Neurodevelopmental conditions (or neurodevelopmental disorders, NDDs) are highly heterogeneous with overlapping characteristics and shared genetic etiology. The large symptom variability and etiological heterogeneity have made it challenging to understand the biological mechanisms underpinning NDDs. To accommodate this individual variability, one approach is to move away from diagnostic criteria and focus on distinct dimensions with relevance to multiple NDDs. This domain approach is well suited to preclinical research, where genetically modified animal models can be used to link genetic variability to neurobiological mechanisms and behavioral traits. Genetic factors associated with NDDs can be grouped functionally into common biological pathways, with one prominent functional group being genes associated with the synapse. These include the neuroligins, a family of postsynaptic transmembrane proteins that are key modulators of synaptic function. Here, we review how research using neuroligin mouse models has provided insight into how synaptic proteins contribute to behavioral traits associated with NDDs. We focus on how mutations in different neuroligins affect social behaviors, as differences in social interaction and communication are a common feature of most NDDs. Importantly, mice carrying distinct mutations in neuroligins share some neurobiological and behavioral phenotypes with other synaptic gene mutations. Comparing the functional implications of mutations in multiple synaptic proteins is a first step toward identifying convergent neurobiological pathways in multiple brain regions and circuits

Establishment and dynamics of the balsam fir seedling bank in old forests of northeastern Quebec

This study examines balsam fir (Abies balsamea (L.) Mill.) recruitment in old fir stands. Studying the regeneration of these stands is essential to understand the regeneration dynamic of the species in the absence of standdestroying disturbances. The objectives were (1) to obtain substrate-seedling associations for different age-classes and according to the presence or absence of adventitious roots; (2) to evaluate the contribution of the seed rain to seedling recruitment; (3) to re-examine age structures using the most appropriate method that minimizes estimation errors due to the presence of adventitious roots. A total of 90 quadrats (1 m2) were established along transects. In each quadrat, subtrates were characterized (type and topography) and their area was estimated. All balsam fir seedlings (<50 cm tall) present in the quadrats were located, harvested whole (root and shoot), and described (age, height, presence of adventitious roots, etc). Fir seedlings were strongly associated with woody mounds covered with thin mats of mixed mosses and Pleurozium shreberi (Bird.) Mitt. but negatively associated with flat topography particularly dominated by Hylocomium splendens (Hedw.) B.S.G. The presence of adventitious root is related to seedling age more than substrate type or topography. The age structure is in agreement with seed production and disturbance regime

Boom and bust of a moose population – a call for integrated forest management

This is the postprint version of the article. The published article can be located at www.springerlink.comThere is increasing pressure to manage forests for multiple objectives, including ecosystem services and biodiversity, alongside timber production. However, few forests are currently co-managed for timber and wildlife, despite potential economic and conservation benefits. We present empirical data from a commercial Norway spruce ( Picea abies ) and Scots pine ( Pinus sylvestris ) production system in southern Norway in which moose ( Alces alces ) are an important secondary product. Combining long-term hunting and forestry records, we identified temporal vari- ation in clear-felling over the past five decades, peaking in the 1970s. Herbicide treatment of regenerating stands and a fivefold increase in moose harvest has lead to a reduction in availability of successional forest per moose of [ 90 % since the 1960s. Field estimates showed that spraying with the herbicide glyphosate reduced forage availability by 60 and 96 % in summer and winter, respectively, 4 years after treatment. It also reduced moose use and habitat selection of young spruce stands compared with unsprayed stands. Together these lines of evidence suggest that forest man- agement led to an increase in moose carrying capacity during the 1970s and a subsequent decline thereafter. This is likely to have contributed to observed reductions in moose population productivity in southern Norway and is counter to sustainable resource management. We therefore call for better integration and long-term planning between forestry and wildlife management to minimise forest damage and the development of large fluctuations in ungulate populations

Burial mounds as settlement indicators : archaeological and palynological investigations at Sangis, northern Sweden

Grave mounds established during the 1st millennium AD in northern Sweden are common in central Norrland, up to northern Ångermanland. There are, however, two grave mounds located 350 km further north, close to the villages of Sangis and Espinära, that stand out as anomalies. These mounds rise questions regarding who established them and why? We hypothesised that they were established close to sedentary settlements, just as the ones found further south. To identify old settlement remains and traces of ancient land use, an archaeological excavation was performed of the sand ridge where the Sangis grave mound is located, and a palynological study was conducted to identify local vegetation changes. The results show that no sedentary settlement accompanied the mound. The area had, however, two phases of land use; as an occasionally visited site from calAD 600 to 800 when the grave mound and possibly a cooking pit was established, and; from calAD 1070 when human impact on the ridge restarted, probably associated to permanent settlements nearby

Burial mounds as settlement indicators : archaeological and palynological investigations at Sangis, northern Sweden

Grave mounds established during the 1st millennium AD in northern Sweden are common in central Norrland, up to northern Ångermanland. There are, however, two grave mounds located 350 km further north, close to the villages of Sangis and Espinära, that stand out as anomalies. These mounds rise questions regarding who established them and why? We hypothesised that they were established close to sedentary settlements, just as the ones found further south. To identify old settlement remains and traces of ancient land use, an archaeological excavation was performed of the sand ridge where the Sangis grave mound is located, and a palynological study was conducted to identify local vegetation changes. The results show that no sedentary settlement accompanied the mound. The area had, however, two phases of land use; as an occasionally visited site from calAD 600 to 800 when the grave mound and possibly a cooking pit was established, and; from calAD 1070 when human impact on the ridge restarted, probably associated to permanent settlements nearby