SummaryDeep layers of the medial entorhinal cortex are considered to relay signals from the hippocampus to other brain structures, but pathways for routing of signals to and from the deep layers are not well established. Delineating these pathways is important for a circuit level understanding of spatial cognition and memory. We find that neurons in layers 5a and 5b have distinct molecular identities, defined by the transcription factors Etv1 and Ctip2, and divergent targets, with extensive intratelencephalic projections originating in layer 5a, but not 5b. This segregation of outputs is mirrored by the organization of glutamatergic input from stellate cells in layer 2 and from the hippocampus, with both preferentially targeting layer 5b over 5a. Our results suggest a molecular and anatomical organization of input-output computations in deep layers of the MEC, reveal precise translaminar microcircuitry, and identify molecularly defined pathways for spatial signals to influence computation in deep layers.

In the original article, the title of Figure 6 was written as ''Hippocampal Outputs Preferentially Target Neurons in L5a.'' The correct title should be ''Hippocampal Outputs Preferentially Target Neurons in L5b.'' This has been corrected online. The authors regret the error. NR1H3 p.Arg415Gln Is Not Associated to Multiple Sclerosis RiskThe International Multiple Sclerosis Genetics Consortium*

ObjectiveTo determine whether a change in editorial policy, including the implementation of a checklist, has been associated with improved reporting of measures which might reduce the risk of bias.MethodsThe study protocol has been published at doi: 10.1007/s11192-016-1964-8.DesignObservational cohort study.PopulationArticles describing research in the life sciences published in Nature journals, submitted after 1 May 2013.InterventionMandatory completion of a checklist during manuscript revision.Comparators(1) Articles describing research in the life sciences published in Nature journals, submitted before May 2013; and (2) similar articles in other journals matched for date and topic.Primary outcomeThe primary outcome is change in the proportion of Nature articles describing in vivo research published before and after May 2013 reporting the ‘Landis 4’ items (randomisation, blinding, sample size calculation and exclusions). We included 448 Nature Publishing Group (NPG) articles (223 published before May 2013, and 225 after) identified by an individual hired by NPG for this specific task, working to a standard procedure; and an independent investigator used PubMed ‘Related Citations’ to identify 448 non-NPG articles with a similar topic and date of publication from other journals; and then redacted all articles for time-sensitive information and journal name. Redacted articles were assessed by two trained reviewers against a 74-item checklist, with discrepancies resolved by a third.Results394 NPG and 353 matching non-NPG articles described in vivo research. The number of NPG articles meeting all relevant Landis 4 criteria increased from 0/203 prior to May 2013 to 31/181 (16.4%) after (two-sample test for equality of proportions without continuity correction, Χ²=36.2, df=1, p=1.8×10−9). There was no change in the proportion of non-NPG articles meeting all relevant Landis 4 criteria (1/164 before, 1/189 after). There were more substantial improvements in the individual prevalences of reporting of randomisation, blinding, exclusions and sample size calculations for in vivo experiments, and less substantial improvements for in vitro experiments.ConclusionThere was an improvement in the reporting of risks of bias in in vivo research in NPG journals following a change in editorial policy, to a level that to our knowledge has not been previously observed. However, there remain opportunities for further improvement.

The ability to learn progressively declines with age. Neural hyperactivity has been implicated in impairing cognitive plasticity with age, but the molecular mechanisms remain elusive. Here, we show that chronic excitation of the Caenorhabditis elegans O2-sensing neurons during ageing causes a rapid decline of experience-dependent plasticity in response to environmental O2 concentration, whereas sustaining lower activity of O2-sensing neurons retains plasticity with age. We demonstrate that neural activity alters the ageing trajectory in the transcriptome of O2-sensing neurons, and our data suggest that high-activity neurons redirect resources from maintaining plasticity to sustaining continuous firing. Sustaining plasticity with age requires the K+-dependent Na+/Ca2+ (NCKX) exchanger, whereas the decline of plasticity with age in high-activity neurons acts through calmodulin and the scaffold protein Kidins220. Our findings demonstrate directly that the activity of neurons alters neuronal homeostasis to govern the age-related decline of neural plasticity and throw light on the mechanisms involved.

The nervous system is a central regulator of longevity, but how neuronal communication interfaces with ageing pathways is not well understood. Gap junctions are key conduits that allow voltage and metabolic signal transmission across cellular networks, yet it has remained unexplored whether they play a role in regulating ageing and longevity. We show that the innexin genes encoding gap junction subunits in Caenorhabditis elegans have extensive and diverse impacts on lifespan. Loss of the neural innexin unc-9 increases longevity by a third and also strongly benefits healthspan. Unc-9 acts specifically in a glutamatergic circuit linked to mechanosensation. Absence of unc-9 depends on a functional touch-sensing machinery to regulate lifespan and alters the age-dependent decline of mechanosensory neurons. The life extension produced by removal of unc-9 requires reactive oxygen species. Our work reveals for the first time that gap junctions are important regulators of ageing and lifespan.is currently unknown whether gap junction coupling as a key intercellular communication channel contributes to the regulation of ageing and longevity.Here we set out to explore if gap junctions affect ageing using the nematode Caenorhabditis elegans, an outstanding model for studies on ageing 14,15 . We assayed the lifespan of loss-offunction mutants of most of the 25 C. elegans innexins and discovered that innexins have a significant impact on lifespan, some leading to an extension of lifespan while others shorten it. Surprisingly, most null mutations of neural innexins extended lifespan, with loss of unc-9, the most widely expressed innexin in the nervous system, increasing longevity by a third. Its selective removal from glutamatergic neurons led to an increase in lifespan and points to a mechanosensory circuit where UNC-9 regulates ageing. Our results show that UNC-9 alters the age-dependent decline of touch-sensing neurons and depends on functional touch sensation as well as reactive oxygen species to modulate lifespan. This study gives strong evidence to suggest an important and previously unknown role for gap junction intercellular communication in shaping ageing and longevity. ResultsThe C. elegans gap junction genes regulate longevity As there is extensive intercellular gap junction coupling in all organs of C. elegans, we hypothesised that gap junction channels may play specific roles in organismal ageing and longevity. The channel subunits encoded by 25 innexin genes show diverse, highly combinatorial, plastic and dynamic expression in virtually all organs and cells of this animal.The gap junction channels these innexins form play key roles in intercellular communication [16][17][18] . We asked if innexins influence longevity, which has not been known. To this end we performed lifespan assays in loss-of-function mutants of all innexins except inx-3, inx-12 and inx-13; these genes are essential for embryonic development or osmoregulation and their loss confers a lethal phenotype 18,19 . Loss-of-function mutants are availab...