Cognition and functional connectivity

BACKGROUND: Amnestic mild cognitive impairment (aMCI), which is recently considered as a high risk status for developing Alzheimer's disease (AD), manifests with gray matter atrophy and increased focal functional activity in the medial temporal lobe (MTL). However, the abnormalities of whole-brain functional network connectivity in aMCI and its relationship to medial temporal atrophy (MTA) remain unknown. METHODS: In this study, thirty-six aMCI patients and thirty-five healthy controls (HCs) were recruited...

Objective: Increased variability in cognition with age has been argued as an indication of pathological processes. Focusing on early detection of neurodegenerative disorders, we investigated variability in cognition in healthy middle-aged adults. In order to understand possible determinants of this variability, we also investigated associations with cognitive reserve, neuroimaging markers, subjective memory complaints, depressive symptomatology, and gender. Method: Thirty-one 50 ± 2 years old individuals were investigated as target group and deviation was studied in comparison to a reference younger group of 30 individuals 40 ± 2 years old...

This study explores the effect of individual differences in the age of acquisition of a second language using resting-state functional magnetic resonance imaging (rs-fMRI) to examine functional connectivity and its relation with cognitive control within bilinguals. We compared simultaneous bilinguals, who learned two languages from birth, to sequential bilinguals, who learned a second language following mastery of their first language. Results show an effect of language experience on the strength of anticorrelation between the default mode network and the task-positive attention network and on cognitive control, with simultaneous bilinguals demonstrating stronger anticorrelations between the two networks, as well as superior cognitive control compared to sequential bilinguals...

Poor response inhibition is a hallmark of pediatric traumatic brain injury (TBI). We assessed motor response inhibition by measuring commission error rates on Simple (minimized cognitive demands) and Motivation (monetary reward) Go/No-Go tasks, comparing 17 children with chronic TBI (> one year post-injury) and 14 matched, uninjured peers. Using resting state fMRI, we examined between-group differences in whole-brain intrinsic connectivity of the motor network as derived from the averaged time course of bilateral primary motor cortex seeds to identify regions of interest (ROIs) for brain-behavior correlations...

Schizophrenia is considered to be a disorder of brain connectivity, which might result from a disproportionally impaired rich-club organization. The rich-club is composed of highly interconnected hub regions that play crucial roles in integrating information between different brain regions. Few studies have yet investigated whether the structural rich-club organization is impaired in patients and their first-degree relatives. In this study, we established a weighted network model of white matter connections using diffusion tensor imaging of 19 patients and 39 unaffected parents, 22 young healthy controls for the patients, and 25 old healthy controls for the parents...

The insular cortex, or "Island of Reil," is hidden deep within the lateral sulcus of the brain. Subdivisions within the insula have been identified on the basis of cytoarchitectonics, sulcal landmarks, and connectivity. Depending on the parcellation technique used, the insula can be divided into anywhere between 2 and 13 distinct subdivisions. The insula subserves a wide variety of functions in humans ranging from sensory and affective processing to high-level cognition. Here, we provide a concise summary of known structural and functional features of the human insular cortex with a focus on lesion case studies and recent neuroimaging evidence for considerable functional heterogeneity of this brain region...

Parkinson's disease (PD) patients show cognitive deficits that are relevant in terms of prognosis and quality of life. Degeneration of striatal dopaminergic afferents proceeds from dorsal/caudal to anterior/ventral and is discussed to account for some of these symptoms. Treatment with dopamine (DA) has differential effects on cognitive dysfunctions, improving some and worsening others. We hypothesized that cognitive performance during the dopaminergic OFF state correlates with DAT availability in the associative striatum...

Analysis of brain functional connectivity network (BFCN) has shown great potential in understanding brain functions and identifying biomarkers for neurological and psychiatric disorders, such as Alzheimer's disease and its early stage, mild cognitive impairment (MCI). In all these applications, the accurate construction of biologically meaningful brain network is critical. Due to the sparse nature of the brain network, sparse learning has been widely used for complex BFCN construction. However, the conventional l1-norm penalty in the sparse learning equally penalizes each edge (or link) of the brain network, which ignores the link strength and could remove strong links in the brain network...

Dendritic spines are the major sites of synaptic transmission in the central nervous system. Alterations in the strength of synaptic connections directly affect the neuronal communication, which is crucial for brain function as well as the processing and storage of information. Sleep and sleep loss bidirectionally alter structural plasticity, by affecting spine numbers and morphology, which ultimately can affect the functional output of the brain in terms of alertness, cognition, and mood. Experimental data from studies in rodents suggest that sleep deprivation may impact structural plasticity in different ways...

The Arabidopsis gene RESISTANCE TO POWDERY MILDEW8.1 (RPW8.1) confers resistance to virulent fungal and oomycete pathogens that cause powdery mildew and downy mildew, respectively. However, the underlying mechanism remains unclear. Here, we show that ectopic expression of RPW8.1 boosts pattern-triggered immunity (PTI) resulting in enhanced resistance against different pathogens in both Arabidopsis and rice. In Arabidopsis, transcriptome analysis revealed that ectopic expression of RPW8.1-YFP constitutively up-regulates expression of many pathogen-associated molecular pattern-(PAMP-) inducible genes...

Skeletal overgrowth is a characteristic of several genetic disorders that are linked to specific molecular signaling cascades. Recently, we established a novel overgrowth syndrome (Kosaki overgrowth syndrome, OMIM #616592) arising from a de novo mutation in PDGFRB, that is, c.1751C>G p.(Pro584Arg). Subsequently, other investigators provided in vitro molecular evidence that this specific mutation in the juxtamembrane domain of PDGFRB causes an overgrowth phenotype and is the first gain-of-function point mutation of PDGFRB to be reported in humans...

Mindfulness meditators often show greater efficiency in resolving response conflicts than non-meditators. However, the neural mechanisms underlying the improved behavioral efficiency are unclear. Here, we investigated frontal theta dynamics-a neural mechanism involved in cognitive control processes-in long-term mindfulness meditators. The dynamics of EEG theta oscillations (4-8 Hz) recorded over the medial frontal cortex (MFC) were examined in terms of their power (MFC theta power) and their functional connectivity with other brain areas (the MFC-centered theta network)...

Important scientific and clinical questions persist about general anesthesia despite the ubiquitous clinical use of anesthetic drugs in humans since their discovery. For example, it is not known how the brain reconstitutes consciousness and cognition after the profound functional perturbation of the anesthetized state, nor has a specific pattern of functional recovery been characterized. To date, there has been a lack of detailed investigation into rates of recovery and the potential orderly return of attention, sensorimotor function, memory, reasoning and logic, abstract thinking, and processing speed...

Cortico-striato-thalamo-cortical (CSTC) circuit has been implicated in OCD pathophysiology by converging neuroimaging findings. The anterior cingulate cortex (ACC), as an important part within CSTC circuit, plays a critical role in OCD etiology. The ACC can be divided into dorsal and rostral parts anatomically, which are involved in cognitive process and emotional function, respectively. However, the diverse function of intrinsic signals from dorsal and rostral ACC regions remains unclear in OCD study. In this work, we applied resting-state functional magnetic resonance imaging (rs-fMRI) technology to investigate and differentiate the functional connectivity (FC) characteristics between dACC and rACC in unmedicated OCD patients...

BACKGROUND: Cognitive behavioural therapy (CBT), including exposure and ritual prevention, is a first-line treatment for obsessive-compulsive disorder (OCD), but few reliable predictors of CBT outcome have been identified. Based on research in animal models, we hypothesized that individual differences in basolateral amygdala-ventromedial prefrontal cortex (BLA-vmPFC) communication would predict CBT outcome in patients with OCD. METHODS: We investigated whether BLA-vmPFC resting-state functional connectivity (rs-fc) predicts CBT outcome in patients with OCD...

Cross-population covariance of brain morphometric quantities provides a measure of interareal connectivity, as it is believed to be determined by the coordinated neurodevelopment of connected brain regions. Although useful, structural covariance analysis predominantly employed bulky morphological measures with mixed compartments, whereas studies of the structural covariance of any specific subdivisions such as myelin are rare. Characterizing myelination covariance is of interest, as it will reveal connectivity patterns determined by coordinated development of myeloarchitecture between brain regions...

Striatal cholinergic interneurons (CIN) are pivotal for the regulation of the striatal network. Acetylcholine (ACh) released by CIN is centrally involved in reward behavior as well as locomotor or cognitive functions. Recently, BAC transgenic mice expressing channelrhodopsin-2 (ChR2) protein under the control of the choline acetyltransferase (ChAT) promoter (ChAT-ChR2) and displaying almost 50 extra copies of the VAChT gene were used to dissect cholinergic circuit connectivity and function using optogenetic approaches...

The pharmacological modulation of glutamatergic neurotransmission to improve cognitive function has been a focus of intensive research, particularly in relation to the cognitive deficits seen in schizophrenia. Despite this effort there has been little success in the clinical use of glutamatergic compounds as procognitive drugs. Here we review a selection of the drugs used to modulate glutamatergic signalling and how they impact on cognitive function in rodents and humans. We highlight how glutamatergic dysfunction, and NMDA receptor hypofunction in particular, is a key mechanism contributing to the cognitive deficits observed in schizophrenia, and outline some of the glutamatergic targets that have been tested as putative procognitive targets for the disorder...

Recent years have seen the rise in popularity of the resting state approach to neurocognitive aging, with many studies examining age differences in functional connectivity at rest and relating these differences to cognitive performance outside the scanner. There are many advantages to the resting state that likely contribute to its popularity and indeed, many insights have been gained from this work. However, there are also several limitations of the resting state approach that restrict its ability to contribute to the study of neurocognitive aging...

Nuclear calcium is an important signaling end-point in synaptic excitation-transcription coupling that is critical for long-term neuroadaptations. Here we show that nuclear calcium acting via a target gene VEGFD is required for hippocampus-dependent fear memory consolidation and extinction in mice. Nuclear calcium-VEGFD signaling upholds structural integrity and complexity of the dendritic arbor of CA1 neurons that renders those cells permissive for the efficient generation of synaptic input-evoked nuclear calcium transients driving the expression of plasticity-related genes...