Impact of a national dementia research consortium: The Canadian Consortium on Neurodegeneration in Aging (CCNA).

The Canadian Consortium on Neurodegeneration in Aging (CCNA) was created by the Canadian federal government through its health research funding agency, the Canadian Institutes for Health Research (CIHR), in 2014, as a response to the G7 initiative to fight dementia. Two five-year funding cycles (2014-2019; 2019-2024) have occurred following peer review, and a third cycle (Phase 3) has just begun. A unique construct was mandated, consisting of 20 national teams in Phase I and 19 teams in Phase II (with research topics spanning from basic to clinical science to health resource systems) along with cross-cutting programs to support them.

Sparsity of Population Activity in the Hippocampus Is Task-Invariant Across the Trisynaptic Circuit and Dorsoventral Axis.

Evidence from neurophysiological and genetic studies demonstrates that activity sparsity-the proportion of neurons that are active at a given time in a population-systematically varies across the canonical trisynaptic circuit of the hippocampus. Recent work has also shown that sparsity varies across the hippocampal dorsoventral (long) axis, wherein activity is sparser in ventral than dorsal regions. While the hippocampus has a critical role in long-term memory (LTM), whether sparsity across the trisynaptic circuit and hippocampal long axis is task-dependent or invariant remains unknown.

A meta-analysis of the effects of early life stress on the prefrontal cortex transcriptome suggests long-term effects on myelin.

Background: Early life stress (ELS) refers to exposure to negative childhood experiences, such as neglect, disaster, and physical, mental, or emotional abuse. ELS can permanently alter the brain, leading to cognitive impairment, increased sensitivity to future stressors, and mental health risks. The prefrontal cortex (PFC) is a key brain region implicated in the effects of ELS.

Identifying representational structure in CA1 to benchmark theoretical models of cognitive mapping.

Decades of theoretical and empirical work have suggested the hippocampus instantiates some form of a cognitive map. Yet, tests of competing theories have been limited in scope and largely qualitative in nature. Here, we develop a novel framework to benchmark model predictions against observed neuronal population dynamics as animals navigate a series of geometrically distinct environments.

Plasma phosphorylated tau181 outperforms [F] fluorodeoxyglucose positron emission tomography in the identification of early Alzheimer disease.

Background And Purpose: This study was undertaken to compare the performance of plasma p-tau181 with that of [F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the identification of early biological Alzheimer disease (AD).

Methods: We included 533 cognitively impaired participants from the Alzheimer's Disease Neuroimaging Initiative. Participants underwent PET scans, biofluid collection, and cognitive tests.

Maternal Depressive Symptoms and Risk for Childhood Depression: Role of Executive Functions.

Objective: Offspring of mothers with depression are at increased risk for executive function (EF) deficits and later depressive symptoms, but limited studies have examined EF as an intermediary pathway. This study examined the role of EF in mediating the association between maternal and child depressive symptoms.

Method: Data were from a longitudinal birth cohort comprising 739 participants followed from the antenatal period for 12 years.

Pandemic-related prenatal maternal stress, model of maternity care and postpartum mental health: The Australian BITTOC study.

Problem: Women pregnant during the COVID-19 pandemic may be at risk of elevated postpartum mental health problems.

Background: Social support protects maternal mental health during a pandemic. It is possible that formal supports, such as continuity maternity models of care, may also support maternal wellbeing.

Spatiotemporal resonance in mouse primary visual cortex.

Human primary visual cortex (V1) responds more strongly, or resonates, when exposed to ∼10, ∼15-20, and ∼40-50 Hz rhythmic flickering light. Full-field flicker also evokes the perception of hallucinatory geometric patterns, which mathematical models explain as standing-wave formations emerging from periodic forcing at resonant frequencies of the simulated neural network. However, empirical evidence for such flicker-induced standing waves in the visual cortex was missing.

PET radiomics-based lymphovascular invasion prediction in lung cancer using multiple segmentation and multi-machine learning algorithms.

The current study aimed to predict lymphovascular invasion (LVI) using multiple machine learning algorithms and multi-segmentation positron emission tomography (PET) radiomics in non-small cell lung cancer (NSCLC) patients, offering new avenues for personalized treatment strategies and improving patient outcomes. One hundred and twenty-six patients with NSCLC were enrolled in this study. Various automated and semi-automated PET image segmentation methods were applied, including Local Active Contour (LAC), Fuzzy-C-mean (FCM), K-means (KM), Watershed, Region Growing (RG), and Iterative thresholding (IT) with different percentages of the threshold.

Optogenetic silencing of medial septal GABAergic neurons disrupts grid cell spatial and temporal coding in the medial entorhinal cortex.

The hippocampus and medial entorhinal cortex (MEC) form a cognitive map that facilitates spatial navigation. As part of this map, MEC grid cells fire in a repeating hexagonal pattern across an environment. This grid pattern relies on inputs from the medial septum (MS).

Proteomic evidence of depression-associated astrocytic dysfunction in the human male olfactory bulb.

The olfactory bulb (OB), a major structure of the limbic system, has been understudied in human investigations of psychopathologies such as depression. To explore more directly the molecular features of the OB in depression, a global comparative proteome analysis was carried out with human post-mortem OB samples from 11 males having suffered from depression and 12 healthy controls. We identified 188 differentially abundant proteins (with adjusted p < 0.

Examining the experiences of student peer support workers delivering care within post-secondary institutions.

Despite experiencing exacerbation of mental health issues, post-secondary students may not seek help due to perceived stigma, overreliance on the self, or preference for nonprofessional supports - including peer support. This study aimed to understand peer support workers' (PSWs) perspectives regarding providing support for mental health concerns in post-secondary institutions. 41 PSWs were recruited from two post-secondary institutions.

Emergency Department Use among Patients with Mental Health Problems: Profiles, Correlates, and Outcomes.

Patients with mental health (MH) problems are known to use emergency departments (EDs) frequently. This study identified profiles of ED users and associated these profiles with patient characteristics and outpatient service use, and with subsequent adverse outcomes. A 5-year cohort of 11,682 ED users was investigated (2012-2017), using Quebec (Canada) administrative databases.

Roles of AMPA receptors in social behaviors.

As a crucial player in excitatory synaptic transmission, AMPA receptors (AMPARs) contribute to the formation, regulation, and expression of social behaviors. AMPAR modifications have been associated with naturalistic social behaviors, such as aggression, sociability, and social memory, but are also noted in brain diseases featuring impaired social behavior. Understanding the role of AMPARs in social behaviors is timely to reveal therapeutic targets for treating social impairment in disorders, such as autism spectrum disorder and schizophrenia.

Profiles of quality of outpatient care among individuals with mental disorders based on survey and administrative data.

Rationale: Though it is crucial to contribute to patient recovery through access, diversity, continuity and regularity of outpatient care, still today most of these are deemed nonoptimal. Identifying patient profiles based on outpatient service use and quality of care indicators might help formulate more personalized interventions and reduce adverse outcomes.

Aims And Objectives: This study aimed to identify profiles of individuals with mental disorders (MDs) patterned after their outpatient care use and quality of care received, and to link those profiles to individual characteristics and subsequent outcomes.

Striatal projection neurons coexpressing dopamine D1 and D2 receptors modulate the motor function of D1- and D2-SPNs.

The role of the striatum in motor control is commonly assumed to be mediated by the two striatal efferent pathways characterized by striatal projection neurons (SPNs) expressing dopamine (DA) D1 receptors or D2 receptors (D1-SPNs and D2-SPNs, respectively), without regard to SPNs coexpressing both receptors (D1/D2-SPNs). Here we developed an approach to target these hybrid SPNs in mice and demonstrate that, although these SPNs are less abundant, they have a major role in guiding the motor function of the other two populations. D1/D2-SPNs project exclusively to the external globus pallidus and have specific electrophysiological features with distinctive integration of DA signals.

Loss of dysbindin-1 in excitatory neurons in mice impacts NMDAR-dependent behaviors, neuronal morphology and synaptic transmission in the ventral hippocampus.

Dysbindin-1, a protein encoded by the schizophrenia susceptibility gene DTNBP1, is reduced in the hippocampus of schizophrenia patients. It is expressed in various cellular populations of the brain and implicated in dopaminergic and glutamatergic transmission. To investigate the impact of reduced dysbindin-1 in excitatory cells on hippocampal-associated behaviors and synaptic transmission, we developed a conditional knockout mouse model with deletion of dysbindin-1 gene in CaMKIIα expressing cells.

Perceived Higher Unmet Care Needs among Adults in Permanent Supportive Housing.

This study is original in that it assesses various types of care needs, barriers to care, and factors associated with higher unmet needs among 308 permanent supportive housing (PSH) residents in Quebec (Canada). Data from structured interviews that featured the Perceived Need for Care Questionnaire were collected from 2020 to 2022, controlling for the COVID-19 pandemic period. Eight types of care (e.

Genetic Risk For Depression and Quality of Life in Patients With Head and Neck Cancer.

Importance: Although patients with head and neck cancer (HNC) have been shown to experience high distress, few longitudinal studies include a comprehensive evaluation of biopsychosocial factors affecting quality of life (QoL), including genetic risk for depression.

Objective: To identify factors at the time of cancer diagnosis associated with QoL scores at 3 months after treatment in patients newly diagnosed with a first occurrence of HNC.

Design, Setting, And Participants: This prospective longitudinal study of 1464 participants with a 3-month follow-up, including structured clinical interviews and self-administered measures was carried out at the Department of Otolaryngology Head and Neck Surgery at 2 tertiary care McGill University Affiliated Hospitals, McGill University Health Centre, and Jewish General Hospital.

Model of negative affect induced by withdrawal from acute and chronic morphine administration in male mice.

Opioid use disorder (OUD) is a chronic relapsing disorder that is a major burden for the lives of affected individuals, and society as a whole. Opioid withdrawal is characterized by strong physical symptoms, along with signs of negative affect. Negative affect due to opioid withdrawal is a major obstacle to recovery and relapse prevention.