Early remodeling of the neocortex upon episodic memory encoding

Understanding the mechanisms by which long-term memories are formed and stored in the brain represents a central aim of neuroscience. Prevailing theory suggests that long-term memory encoding involves early plasticity within hippocampal circuits, whereas reorganization of the neocortex is thought to occur weeks to months later to subserve remote memory storage. Here we report that long-term memory encoding can elicit early transcriptional, structural, and functional remodeling of the neocortex. Parallel studies using genome-wide RNA sequencing, ultrastructural imaging, and whole-cell recording in wild-type mice suggest that contextual fear conditioning initiates a transcriptional program in the medial prefrontal cortex (mPFC) that is accompanied by rapid expansion of the synaptic active zone and postsynaptic density, enhanced dendritic spine plasticity, and increased synaptic efficacy. To address the real-time contribution of the mPFC to long-term memory encoding, we performed temporally precise optogenetic inhibition of excitatory mPFC neurons during contextual fear conditioning. Using this approach, we found that real-time inhibition of the mPFC inhibited activation of the entorhinal–hippocampal circuit and impaired the formation of long-term associative memory. These findings suggest that encoding of long-term episodic memory is associated with early remodeling of neocortical circuits, identify the prefrontal cortex as a critical regulator of encoding-induced hippocampal activation and long-term memory formation, and have important implications for understanding memory processing in healthy and diseased brain states.Picower Institute for Learning and Memory (Innovation Fund)Massachusetts Institute of Technology. Department of Brain and Cognitive SciencesBrightFocus Foundation (Research Fellowship A2013026F

Basolateral amygdala bidirectionally modulates stress-induced hippocampal learning and memory deficits through a p25/Cdk5-dependent pathway

Repeated stress has been suggested to underlie learning and memory deficits via the basolateral amygdala (BLA) and the hippocampus; however, the functional contribution of BLA inputs to the hippocampus and their molecular repercussions are not well understood. Here we show that repeated stress is accompanied by generation of the Cdk5 (cyclin-dependent kinase 5)-activator p25, up-regulation and phosphorylation of glucocorticoid receptors, increased HDAC2 expression, and reduced expression of memory-related genes in the hippocampus. A combination of optogenetic and pharmacosynthetic approaches shows that BLA activation is both necessary and sufficient for stress-associated molecular changes and memory impairments. Furthermore, we show that this effect relies on direct glutamatergic projections from the BLA to the dorsal hippocampus. Finally, we show that p25 generation is necessary for the stress-induced memory dysfunction. Taken together, our data provide a neural circuit model for stress-induced hippocampal memory deficits through BLA activity-dependent p25 generation.National Institutes of Health (U.S.) (Grant AG047661)National Institutes of Health (U.S.) (Grant NS051874)JPB FoundationSwiss National Science Foundation (Grant for Prospective Researchers)Human Frontier Science Program (Strasbourg, France) (Long-Term Postdoctoral Fellowship

Gamma frequency entrainment attenuates amyloid load and modifies microglia

Changes in gamma oscillations (20-50 Hz) have been observed in several neurological disorders. However, the relationship between gamma oscillations and cellular pathologies is unclear. Here we show reduced, behaviourally driven gamma oscillations before the onset of plaque formation or cognitive decline in a mouse model of Alzheimer's disease. Optogenetically driving fast-spiking parvalbumin-positive (FS-PV)-interneurons at gamma (40 Hz), but not other frequencies, reduces levels of amyloid-β (Aβ)[subscript 1-40] and Aβ [subscript 1-42] isoforms. Gene expression profiling revealed induction of genes associated with morphological transformation of microglia, and histological analysis confirmed increased microglia co-localization with Aβ. Subsequently, we designed a non-invasive 40 Hz light-flickering regime that reduced Aβ[subscript 1-40] and Aβ[subscript 1-42] levels in the visual cortex of pre-depositing mice and mitigated plaque load in aged, depositing mice. Our findings uncover a previously unappreciated function of gamma rhythms in recruiting both neuronal and glial responses to attenuate Alzheimer's-disease-associated pathology.National Institutes of Health (U.S.) (Grant 1R01EY023173)National Institutes of Health (U.S.) (Grant 1DP1NS087724)National Institutes of Health (U.S.) (Grant RF1AG047661)National Institutes of Health (U.S.) (Grant ROIGM104948

A multi-disciplinary commentary on preclinical research to investigate vascular contributions to dementia

Although dementia research has been dominated by Alzheimer's disease (AD), most dementia in older people is now recognised to be due to mixed pathologies, usually combining vascular and AD brain pathology. Vascular cognitive impairment (VCI), which encompasses vascular dementia (VaD) is the second most common type of dementia. Models of VCI have been delayed by limited understanding of the underlying aetiology and pathogenesis. This review by a multidisciplinary, diverse (in terms of sex, geography and career stage), cross-institute team provides a perspective on limitations to current VCI models and recommendations for improving translation and reproducibility. We discuss reproducibility, clinical features of VCI and corresponding assessments in models, human pathology, bioinformatics approaches, and data sharing. We offer recommendations for future research, particularly focusing on small vessel disease as a main underpinning disorder

A Multi-disciplinary Commentary on Preclinical Research to investigate Vascular Contributions to Dementia

Although dementia research has been dominated by Alzheimer's disease (AD), most dementia in older people is now recognised to be due to mixed pathologies, usually combining vascular and AD brain pathology. Vascular cognitive impairment (VCI), which encompasses vascular dementia (VaD) is the second most common type of dementia. Models of VCI have been delayed by limited understanding of the underlying aetiology and pathogenesis. This review by a multidisciplinary, diverse (in terms of sex, geography and career stage), cross-institute team provides a perspective on limitations to current VCI models and recommendations for improving translation and reproducibility. We discuss reproducibility, clinical features of VCI and corresponding assessments in models, human pathology, bioinformatics approaches, and data sharing. We offer recommendations for future research, particularly focusing on small vessel disease as a main underpinning disorder.</p

Management matters

Fewer than 50% of registered dietitians (RDs) supervise personnel and 76% have no budget authority. Because higher salaries are tied to increasing levels of authority and responsibility, RDs must seek management and leadership roles to enjoy the increased remuneration tied to such positions. Advanced-level practice in any area of dietetics demands powerful communication abilities, proficiency in budgeting and finance, comfort with technology, higher-order decision-making/problem-solving skills, and well-honed human resource management capabilities, all foundational to competent management practice. As RDs envision the future of the dietetics profession, practitioners must evaluate management competence in both hard and soft skills. Just as research is needed to support evidence-based clinical practice, the same is needed to support management practice across the profession. Dietetics educators and preceptors should be as enthusiastic about management practice as they are clinical practice when educating and mentoring future professionals. Such encouragement and support can mean that new RDs and dietetic technicians, registered, will understand what it takes to advance to higher levels of responsibility, authority, and subsequent enhanced remuneration. In the ever-changing social, legal, ethical, political, economic, technological, and ecological environments of work, food and nutrition professionals who are willing to step forward and assume the risks and responsibilities of management also will share in the rewards, and propel the profession to new heights of recognition and respect

4D mapping of network-specific pathological propagation in Alzheimer's disease

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Brain and Cognitive Sciences, 2016.Cataloged from PDF version of thesis.Includes bibliographical references (pages 113-132).Alzheimer's disease (AD) causes a devastating loss of memory and cognition for which there is no cure. Without effective treatments that slow or reverse the course of the disease, the rapidly aging population will require astronomical investment from society to care for the increasing numbers of AD patients. Additionally, the financial and emotional burden on families of affected individuals will be profound. Traditional approaches to the study of AD use either biochemical assays to probe cellular pathophysiology or non-invasive imaging platforms to investigate brain-wide network alterations. Though decades of research using these tools have advanced the field significantly, our increased understanding of AD has not led to successful interventions. One reason for this impediment may be that the tools used in neither approach can achieve the spatial and temporal precision necessary to study the consequences of molecular insults across the brain over time. In this thesis, I capitalize on recent advances in tissue processing technologies to gain a network-level perspective on the molecular and cellular progression of AD. First, I present optimized methods for in situ proteomic phenotyping of large-volume tissue specimens. Then, I use the techniques to map amyloid-beta (A[beta]) aggregates at the whole-brain scale across disease stages in a mouse model of AD. The spatially-unbiased, temporally-precise map demonstrates hierarchical susceptibility of increasingly large, memory-related brain networks to A[beta] deposition. Importantly, the 4D nature of the map reveals that subcortical nodes and white matter tracts of the Papez memory circuit exhibit unique, early vulnerability to A[beta] aggregates. Finally, using large-volume labeling approaches, I confirm the molecular findings by showing disease-specific A[beta] aggregation in human samples from the early hub regions. Together, this data unites desperate observations of network-level deficits and identifies critical locations of early A[beta] deposition in the brain. By linking molecular and network observations, I begin to provide biological explanations for the clinical manifestation of AD. This perspective can guide earlier patient identification and refine experimental approaches to developing cognitively efficacious treatments. These discoveries emphasize the necessity of multi-level investigations in neuroscience research and highlight the potential impacts of tools that enable researchers to bridge the gap.by Rebecca Gail Canter.Ph. D

INFORMAS Protocol: Food Labelling Module - Annex 3: Photographic methods for measuring packaged food and beverage products in Supermarkets.

Annex 3: Packaged Food Data Collection in Supermarkets, Chile 2015 (Protocol

A community-based trial of a psychosocial eHealth intervention for parents of children with cancer

BACKGROUND: The Electronic Surviving Cancer Competently Intervention Program (eSCCIP), a psychosocial eHealth intervention for parents and caregivers of children with cancer (parents), was delivered in a community-based psychosocial oncology center. Primary endpoints were intervention acceptability, feasibility, and accessibility, with a secondary exploratory focus on psychosocial outcomes. PROCEDURE: Oncology therapists in a psychosocial oncology center were trained in eSCCIP delivery. Participants were eligible for participation if they were the primary caregiver of a child with cancer between the ages 0 and 17, could read and write in English, and had reliable internet access to complete eSCCIP. Surveys were administered electronically at baseline and post intervention to evaluate study endpoints. Effect sizes (Cohen\u27s d) were computed for exploratory psychosocial outcomes. Nineteen parents completed the intervention. RESULTS: Parents rated eSCCIP as highly acceptable, feasible, and accessible. A large clinical effect was detected for acute distress (d = 0.79). Moderate clinical effects were reported for overall posttraumatic stress disorder (PTSD) symptoms (d = 0.37), negative mood/cognitions (d = 0.59), and symptoms of anxiety (d = 0.48). CONCLUSIONS: Results indicate that eSCCIP is an acceptable, feasible, and accessible psychosocial intervention for parents. Exploratory analyses suggest that participation in eSCCIP may contribute to decreases in acute distress, symptoms of anxiety, and symptoms of PTSD