Gray Regions Research Articles

Prefrontal-limbic Functional Connectivity during Acquisition and Extinction of Conditioned Fear

This study is a new analysis to obtain novel metabolic data on the functional connectivity of prefrontal-limbic regions in Pavlovian fear acquisition and extinction of tone-footshock conditioning. Mice were analyzed with the fluorodeoxyglucose (FDG) autoradiographic method to metabolically map regional brain activity. New FDG data were sampled from the nuclei of the habenula and other regions implicated in aversive conditioning, such as infralimbic cortex, amygdala and periaqueductal gray regions. The activity patterns among these regions were inter-correlated during acquisition, extinction or pseudorandom training to develop a functional connectivity model. Two subdivisions of the habenular complex showed increased activity after acquisition relative to extinction, with the pseudorandom group intermediate between the other two groups. Significant acquisition activation effects were also found in centromedial amygdala, dorsomedial and ventrolateral periaqueductal gray. FDG uptake increases during extinction were found only in dorsal and ventral infralimbic cortex. The overall pattern of activity correlations between these regions revealed extensive but differential functional connectivity during acquisition and extinction training, with less functional connectivity found after pseudorandom training. Interestingly, habenula nuclei showed a distinct pattern of inter-correlations with amygdala nuclei during extinction. The functional connectivity model revealed changing interactions among infralimbic cortex, amygdala, habenula and periaqueductal gray regions through the stages of Pavlovian fear acquisition and extinction. This study provided new data on the contributions of the habenula to fear conditioning, and revealed previously unreported infralimbic-amygdala-habenula-periaqueductal gray interactions implicated in acquisition and extinction of conditioned fear.

Intelligent color correction method of logo pattern in visual communication design

Due to the improper adjustment of light intensity, image distortion is easily caused. The existing correction method is used to compensate the light intensity of the energy distribution map of the hyperspectral logo pattern, which can not effectively identify the color of its logo pattern. In this paper, an intelligent color correction method for logo pattern in visual communication design is presented. By using the background subtraction method and the differential chart’s binary method, the whole gray image of logo pattern is extracted from the acquisition image, a difference map is obtained, and then the difference map is pre processed and extracted. The obtained logo pattern is regarded as the approximate gray region under the standard illumination. At the same time, the approximate estimation of the illuminant color and the average color correction coefficient of the logo pattern are obtained. Finally, each approximate gray area is merged together to correct the color of the logo pattern. The simulation results show that the proposed method can effectively identify the logo patterns, and the corrected logo patterns are not distorted and have strong robustness.

Distinction of the GABA 2.29 ppm resonance using triple refocusing at 3 T in vivo.

To develop 1 H MR spectroscopy that provides distinction of γ-aminobutyric acid (GABA) signal at 3 T in vivo. Triple-refocusing was tailored at 3 T, with numerical simulations and phantom validation, for distinction of the GABA 2.29-ppm resonance from the neighboring glutamate resonance. The optimization was performed on the inter-RF pulse time delays and the duration and carrier frequency of a non-slice-selective RF pulse. The optimized triple refocusing was tested in multiple regions in 6 healthy subjects, including hippocampus. The in vivo spectra were analyzed with the LCModel using in-house basis spectra. After normalization of the metabolite signal estimates to water, the metabolite concentrations were quantified with reference to medial-occipital creatine at 8 mM. A triple-refocusing scheme with optimized inter-RF pulse time delays (TE = 74 ms) was obtained for GABA detection. With optimized duration (14 ms) and carrier frequency (4.5 ppm) of the non-slice-selective RF pulse, the triple refocusing gave rise to distinction between the GABA 2.29-ppm and glutamate 2.35-ppm signals. The GABA 2.29-ppm signal was clearly discernible in spectra in vivo (voxel size 4 to 12 mL; scan times 4.3 to 17 minutes). With a total of 24 spectra from 6 gray or white matter-dominant regions, the GABA concentration was measured to be 0.62 to 1.15 mM (Cramer-Rao lower bound of 8 to 14%), and the glutamate level 5.8 to 11.2 mM (Cramer-Rao lower bound of 3 to 6%). The optimized triple refocusing provided distinction between GABA and glutamate signals and permitted direct codetection of these metabolites in the human brain at 3 T in vivo.

Solvent effects on differentiation of mouse brain tissue using laser microdissection 'cut and drop' sampling with direct mass spectral analysis.

Laser microdissection-liquid vortex capture/electrospray ionization mass spectrometry (LMD-LVC/ESI-MS) has potential for on-line classification of tissue but an investigation into what analytical conditions provide best spectral differentiation has not been conducted. The effects of solvent, ionization polarity, and spectral acquisition parameters on differentiation of mouse brain tissue regions are described. Individual 40 × 40μm microdissections from cortex, white, grey, granular, and nucleus regions of mouse brain tissue were analyzed using different capture/ESI solvents, in positive and negative ion mode ESI, using time-of-flight (TOF)-MS and sequential window acquisitions of all theoretical spectra (SWATH)-MS (a permutation of tandem-MS), and combinations thereof. Principal component analysis-linear discriminant analysis (PCA-LDA), applied to each mass spectral dataset, was used to determine the accuracy of differentiation of mouse brain tissue regions. Mass spectral differences associated with capture/ESI solvent composition manifested as altered relative distributions of ions rather than the presence or absence of unique ions. In negative ion mode ESI, 80/20 (v/v) methanol/water yielded spectra with low signal/noise ratios relative to other solvents. PCA-LDA models acquired using 90/10 (v/v) methanol/chloroform differentiated tissue regions with 100% accuracy while data collected using methanol misclassified some samples. The combination of SWATH-MS and TOF-MS data improved differentiation accuracy. Combined TOF-MS and SWATH-MS data differentiated white, grey, granular, and nucleus mouse tissue regions with greater accuracy than when solely using TOF-MS data. Using 90/10 (v/v) methanol/chloroform, tissue regions were perfectly differentiated. These results will guide future studies looking to utilize the potential of LMD-LVC/ESI-MS for tissue and disease differentiation.

The involvement of the pathway connecting the substantia nigra, the periaqueductal gray matter and the retrotrapezoid nucleus in breathing control in a rat model of Parkinson's disease

Parkinson's disease (PD) is characterized by a reduction in the number of dopaminergic neurons of the substantia nigra (SNpc), accompanied by motor and non-motor deficiencies such as respiratory failure. Here, our aim was to investigate possible neuronal communications between the SNpc and chemoreceptor neurons within the retrotrapezoid nucleus (RTN), in order to explain neurodegeneration and the loss of breathing function in the 6-OHDA PD animal model. Male Wistar rats received tracer injections in the SNpc, RTN and periaqueductal gray (PAG) regions to investigate the projections between those regions. The results showed that neurons of the SNpc project to the RTN by an indirect pathway that goes through the PAG region. In different groups of rats, reductions in the density of neuronal markers (NeuN) and the number of catecholaminergic varicosities in PAG, as well as reductions in the number of CO2-activated PAG neurons with RTN projections, were observed in a 6-OHDA model of PD. Physiological experiments showed that inhibition of the PAG by bilateral injection of muscimol did not produce resting breathing disturbances but instead reduced genioglossus (GGEMG) and abdominal (AbdEMG) muscle activity amplitude induced by hypercapnia in control rats that were urethane-anesthetized, vagotomized, and artificially ventilated. However, in a model of PD, we found reductions in resting diaphragm muscle activity (DiaEMG) and GGEMG frequencies, as well as in hypercapnia-induced DiaEMG, GGEMG and AbdEMG frequencies and GGEMG and AbdEMG amplitudes. Therefore, we can conclude that there is an indirect pathway between neurons of the SNpc and RTN that goes through the PAG and that there is a defect of this pathway in an animal model of PD.

LoRa Performance under Variable Interference and Heavy‐Multipath Conditions

LoRa (or LoRaWAN) is by far the best known representative of narrowband communication systems designed for the Internet of Things. As a system dedicated specifically for long‐range operations, it possesses a considerable processing gain for the energetic link budget improvement and a remarkable immunity to multipath and interference. The paper describes outcomes of measurement campaigns during which the LoRa performance was tested against these two factors, that is, a heavy‐multipath propagation and a controlled, variable interference generated, respectively, in a reverberation chamber and an anechoic chamber. Results allow quantitative appraisal of the system behavior under these harsh conditions with respect to LoRa’s three major configurable parameters: the spreading factor, bandwidth, and code rate. They also allow dividing LoRa configurational space into three distinct sensitivity regions: in the white region it is immune to both interference and multipath propagation, in the light‐grey region it is only immune to the multipath phenomenon but sensitive to interference, and in the dark grey region LoRa is vulnerable to both phenomena.

Intercollicular nucleus electric stimulation encoded “walk forward” commands in pigeons

Abstract The bio-robot research field is growing. Robo-pigeons have been successfully programmed to turn left or right; however, a satisfactory method of commanding a robo-pigeon to walk forward is still lacking. This problem has become a roadblock to progress in bio-robot research and applications. In mammals, the midbrain periaqueductal gray region (PAG) plays a key role in mediating defensive reactions in response to fear and anxiety. The avian intercollicular nucleus (ICo) is thought to correspond to the PAG. In this study, we found that microstimulating the ICo could successfully induce a robo-pigeon to walk forward. Compared with stimulation of the previously used archistriatum, the response time was considerably shorter and the behavior accuracy significantly higher. This paper describes in detail the process of controlling a robo-pigeon such that it walks forward and backward along a prescribed straight line. From the results, we draw the conclusion that the ICo is suitable for prompting the “walk forward” order in robo-pigeons.

Investigation of Sliding Wear Behaviour of HVOF Carbide Coating

In this Present work dry sliding wear tests on specimens of Mild Steel, WC-12Co and WC-10Co-4Cr coated specimens were performed against a hardened EN32 steel disc under dry sliding conditions. High Velocity Oxy-Fuel flame spraying technique (HVOF) was used to deposit the coating on 1020 grade steel then theses coated sample characterized using scanning electron microscopy, X-ray diffraction (XRD), coefficient of friction (COF), hardness The experiment result show MS specimen suffered high wear loss, but the WC-Co and WC-Co-Cr specimen showed negative wear and higher friction coefficient .Hardness is higher in the WC-12Co coating than in the WC-10Co-4Cr coating. The SEM image shows the bright and dark grey regions corresponding to tungsten carbide and cobalt binder phase XRD result shows that decomposition of WC (into W2 C and W) cases lower wear

A simulation study on the impact of the blood flow-dependent component in [18F]AV45 SUVR in Alzheimer's disease.

BackgroundIncreased brain uptake on [18F]AV45 PET is a biomarker for Alzheimer’s disease (AD). The standardised uptake value ratio (SUVR) is widely used for quantification but is subject to variability. Here we evaluate how SUVR of a cortical target region is affected by blood flow changes in the target and two frequently used reference regions.MethodsRegional baseline time-activity curves (TACs) were simulated based on metabolite-corrected plasma input functions and pharmacokinetic parameters obtained from our previously acquired data in healthy control (HC; n = 10), amnestic mild cognitive impairment (aMCI; n = 15) and AD cohorts (n = 9). Blood flow changes were simulated by altering the regional tracer delivery rate K1 (and clearance rate k2) between -40% and +40% from its regional baseline value in the target region and/or cerebellar grey (CB) or subcortical white matter (WM) reference regions. The corresponding change in SUVR was calculated at 50–60 min post-injection.ResultsA -40% blood flow reduction in the target resulted in an increased SUVRtarget (e.g. SUVRprecuneus: +10.0±5% in HC, +2.5±2% in AD), irrespective of the used reference region. A -40% blood flow reduction in the WM reference region increased SUVRWM (+11.5±4% in HC, +13.5±3% in AD) while a blood flow reduction in CB decreased SUVRCB (-9.5±6% in HC, -5.5±2% in AD), irrespective of the used target region. A -40% flow reduction in both the precuneus and reference WM (i.e., global flow change) induced an increased SUVR (+22.5±8% in HC, +16.0±4% in AD). When considering reference CB instead, SUVR was decreased by less than -5% (both in HC and AD).ConclusionBlood flow changes introduce alterations in [18F]AV45 PET SUVR. Flow reductions in the CB and WM reference regions resulted in a decreased and increased SUVR of the target, respectively. SUVR was more affected by global blood flow changes when considering WM instead of CB normalization.

Distribution of NADPH-diaphorase reactivity in the central nervous system of the common toad (Bufo bufo)

We examined the distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-reactive elements in the central nervous system (CNS) of the common toad, Bufo bufo. The investigation involved adult male and female toads collected during the breeding season. Labeled neurons of different morphological appearances (weakly or darkly stained, unipolar, bipolar, and multipolar) and fibers were observed across all subdivisions of the amphibian brain. Overall, a similar distribution of NADPH-d-labeled neurons was observed in the brain of male and female toads. In the secondary prosencephalon NADPH-d-labeled neurons were observed in the olfactory bulbs, pallial regions, nucleus accumbens, diagonal band of Broca, septum, striatum, amygdala, suprachiasmatic and magnocellular preoptic nuclei, dorsal and ventral hypothalamus. In the diencephalon, NADPH-d-positive neurons were seen in the anterior thalamic nuclei, ventromedial and ventrolateral nuclei, central and lateral thalamic nuclei, posterior tubercle, posterodorsal division of the lateral thalamic nucleus, and in the pretectal and pretoral gray. In the mesencephalon, heavily stained neurons were present in the anterodorsal and anteroventral tegmental nuclei, magnocellular, principal and laminar nuclei of the torus semicircularis, and nucleus profundus mesencephali. In the isthmus, stained cells were observed medially and ventrally in the posterodorsal and posteroventral tegmental nuclei. In the rhombencephalon, numerous NADPH-d-stained neurons were distributed in the cerebellar nucleus, sensory and descending trigeminal nuclei, motor nuclei of the glossopharyngeal and vagus nerves, the nucleus of the solitary tract, nuclei of the hypoglossal and octaval nerves, dorsal column nucleus, central gray region, and in reticular formation. However, the complete absence of NADPH-d-stained neurons in the cerebellar cortex was an unusual feature observed in this study. The widespread distribution of NADPH-d staining in diverse cell types, belonging to a variety of neuronal systems suggests a widespread role for NADPH-d in modulating diverse functions, including sensory coding in the amphibian nervous system.

A fully automated hybrid methodology using Cuckoo‐based fuzzy clustering technique for magnetic resonance brain image segmentation

AbstractThis article aims at developing an automated hybrid algorithm using Cuckoo Based Search (CBS) and interval type‐2 fuzzy based clustering, so as to exhibit efficient magnetic resonance (MR) brain image segmentation. An automatic MR brain image segmentation facilitates and enables a radiologist to have a brief review and easy analysis of complicated tumor regions of imprecise gray level regions with minimal user interface. The tumor region having severe intensity variations and suffering from poor boundaries are to be detected by the proposed hybrid technique that could ease the process of clinical diagnosis and this tends to be the core subject of this article. The ability of the proposed technique is compared using standard comparison parameters such as mean squared error, peak signal to noise ratio, computational time, Dice Overlap Index, and Jaccard Tanimoto Coefficient Index. The proposed CBS combined with interval type‐2 fuzzy based clustering produces a sensitivity of 0.7143 and specificity of 0.9375, which are far better than the conventional techniques such as kernel based, entropy based, graph‐cut based, and self‐organizing maps based clustering. Appreciable segmentation results of tumor region that enhances clinical diagnosis is made available through this article and two of the radiologists who have hands on experience in the field of radiology have extended their support in validating the efficiency of the proposed methodology and have given their consent in utilizing the proposed methodology in the processes of clinical oncology.

Male sex pheromone components in Heliconius butterflies released by the androconia affect female choice.

Sex-specific pheromones are known to play an important role in butterfly courtship, and may influence both individual reproductive success and reproductive isolation between species. Extensive ecological, behavioural and genetic studies of Heliconius butterflies have made a substantial contribution to our understanding of speciation. Male pheromones, although long suspected to play an important role, have received relatively little attention in this genus. Here, we combine morphological, chemical and behavioural analyses of male pheromones in the Neotropical butterfly Heliconius melpomene. First, we identify putative androconia that are specialized brush-like scales that lie within the shiny grey region of the male hindwing. We then describe putative male sex pheromone compounds, which are largely confined to the androconial region of the hindwing of mature males, but are absent in immature males and females. Finally, behavioural choice experiments reveal that females of H. melpomene, H. erato and H. timareta strongly discriminate against conspecific males which have their androconial region experimentally blocked. As well as demonstrating the importance of chemical signalling for female mate choice in Heliconius butterflies, the results describe structures involved in release of the pheromone and a list of potential male sex pheromone compounds.

Mapping of thalamic magnetic susceptibility in multiple sclerosis indicates decreasing iron with disease duration: A proposed mechanistic relationship between inflammation and oligodendrocyte vitality

Recent advances in susceptibility MRI have dramatically improved the visualization of deep gray matter brain regions and the quantification of their magnetic properties in vivo, providing a novel tool to study the poorly understood iron homeostasis in the human brain. In this study, we used an advanced combination of the recent quantitative susceptibility mapping technique with dedicated analysis methods to study intra-thalamic tissue alterations in patients with clinically isolated syndrome (CIS) and multiple sclerosis (MS). Thalamic pathology is one of the earliest hallmarks of MS and has been shown to correlate with cognitive dysfunction and fatigue, but the mechanisms underlying the thalamic pathology are poorly understood.We enrolled a total of 120 patients, 40 with CIS, 40 with Relapsing Remitting MS (RRMS), and 40 with Secondary Progressive MS (SPMS). For each of the three patient groups, we recruited 40 controls, group matched for age- and sex (120 total). We acquired quantitative susceptibility maps using a single-echo gradient echo MRI pulse sequence at 3 T. Group differences were studied by voxel-based analysis as well as with a custom thalamus atlas. We used threshold-free cluster enhancement (TFCE) and multiple regression analyses, respectively. We found significantly reduced magnetic susceptibility compared to controls in focal thalamic subregions of patients with RRMS (whole thalamus excluding the pulvinar nucleus) and SPMS (primarily pulvinar nucleus), but not in patients with CIS. Susceptibility reduction was significantly associated with disease duration in the pulvinar, the left lateral nuclear region, and the global thalamus. Susceptibility reduction indicates a decrease in tissue iron concentration suggesting an involvement of chronic microglia activation in the depletion of iron from oligodendrocytes in this central and integrative brain region. Not necessarily specific to MS, inflammation-mediated iron release may lead to a vicious circle that reduces the protection of axons and neuronal repair.

Normobaric hyperoxia does not improve derangements in diffusion tensor imaging found distant from visible contusions following acute traumatic brain injury

We have previously shown that normobaric hyperoxia may benefit peri-lesional brain and white matter following traumatic brain injury (TBI). This study examined the impact of brief exposure to hyperoxia using diffusion tensor imaging (DTI) to identify axonal injury distant from contusions. Fourteen patients with acute moderate/severe TBI underwent baseline DTI and following one hour of 80% oxygen. Thirty-two controls underwent DTI, with 6 undergoing imaging following graded exposure to oxygen. Visible lesions were excluded and data compared with controls. We used the 99% prediction interval (PI) for zero change from historical control reproducibility measurements to demonstrate significant change following hyperoxia. Following hyperoxia DTI was unchanged in controls. In patients following hyperoxia, mean diffusivity (MD) was unchanged despite baseline values lower than controls (p < 0.05), and fractional anisotropy (FA) was lower within the left uncinate fasciculus, right caudate and occipital regions (p < 0.05). 16% of white and 14% of mixed cortical and grey matter patient regions showed FA decreases greater than the 99% PI for zero change. The mechanistic basis for some findings are unclear, but suggest that a short period of normobaric hyperoxia is not beneficial in this context. Confirmation following a longer period of hyperoxia is required.

Skull of the grey heron (Ardea cinerea): Detailed investigation of the orbital region.

The skull of the grey heron (Ardea cinerea) was examined with an emphasis on describing the orbital region. In the young (circa sixteen to seventeen days old) heron, the frontal bone (os frontale) and nasal bone (os nasale) comprised separate paired bones, connected by sutures (sutura interfrontalis, sutura internasalis and sutura frontonasalis plana). In adult animals, the relationship between these bones was different: the left and right frontal bone and the left and right nasal bone had grown together, and the frontal bone and nasal bone had fused into a common frontonasal bone (os frontonasale). In the ectethmoid bone (os ectethmoidale), the main components comprised of the orbital and antorbital part of the ectethmoid plate (lamina ectethmoidalis orbitalis et antorbitalis), the lateral process (processus lateralis ectethmoidalis) and the tubercle (tuberculum ectethmoidalis); the left and right ectethmoid plates were fused together to form the ectethmoid sinus (sinus ectethmoidalis) between them. In the young heron, the anatomical and functional link between the frontal and lacrimal bones did not exist yet, nor did the osseous frame of the ectethmoid-lacrimal complex. Further research into the young heron skulls is needed. This article provides novel insights into the grey heron's orbital region.

Tissue magnetic susceptibility mapping as a marker of tau pathology in Alzheimer's disease

Alzheimer's disease is connected to a number of other neurodegenerative conditions, known collectively as ‘tauopathies’, by the presence of aggregated tau protein in the brain. Neuroinflammation and oxidative stress in AD are associated with tau pathology and both the breakdown of axonal sheaths in white matter tracts and excess iron accumulation grey matter brain regions. Despite the identification of myelin and iron concentration as major sources of contrast in quantitative susceptibility maps of the brain, the sensitivity of this technique to tau pathology has yet to be explored. In this study, we perform Quantitative Susceptibility Mapping (QSM) and T2* mapping in the rTg4510, a mouse model of tauopathy, both in vivo and ex vivo. Significant correlations were observed between histological measures of myelin content and both mean regional magnetic susceptibility and T2* values. These results suggest that magnetic susceptibility is sensitive to tissue myelin concentrations across different regions of the brain. Differences in magnetic susceptibility were detected in the corpus callosum, striatum, hippocampus and thalamus of the rTg4510 mice relative to wild type controls. The concentration of neurofibrillary tangles was found to be low to intermediate in these brain regions indicating that QSM may be a useful biomarker for early stage detection of tau pathology in neurodegenerative diseases.

Corrigendum: Towards an Understanding of Li2 O2 Evolution in Li-O2 Batteries: An In Operando Synchrotron X-ray Diffraction Study.

An error in the units of the y axis of Figure 2 d was found. The units should be Å instead of nm (1 nm=10 Å). In the published Full Paper, there were no conclusions related to these absolute values that would affect the scientific content of this publication. The original and corrected Figure 1 is shown below. Left: original, right: corrected. (a) Galvanostatic discharge–charge of Li–O2 cells with CNT electrode, (b) showing the evolution of Li2O2 mass, (c) the efficiency (%) of Li2O2, and (d) the average domain size as a function of time at current density of 0.15 mA cm−2, respectivly. The gray region corresponds to a temporary loss of beam. The text on page 4 (left column) of the Full paper should read: “Figure 2d shows that the average Li2O2 domain size sharply increased to 170 Å during the first discharge step with growth along both [100] and [101] directions. During the following part of discharge, the average domain size was reduced to 120 Å, with the size along the [101] direction remaining unchanged whereas that along the [100] direction decreased.” And the text on page 4 (right column) should read: “From FullProf refinements, we obtained the apparent dimensions of 170 and 80 Å for the (100) and (101) reflections at the end of discharge.” In addition, Figure S2 in the Supporting Information was also updated. Left: original, right: corrected. (Original) (a) Galvanostatic discharge–charge of Li–O2 cells with CNT electrode, (b) the evolution of the Li2O2 mass, (c) the efficiency (%) of Li2O2 evolution, and (d) the average domain size as a function of time at current density of 0.075 mA cm-2, respectively. The authors and the editorial office apologize for this oversight and for any inconvenience caused.

Assessment of gray and white matter structural alterations in migraineurs without aura

BackgroundMigraine constitute a disorder characterized by recurrent headaches, and have a high prevalence, a high socio-economic burden and severe effects on quality of life. Our previous fMRI study demonstrated that some brain regions are functional alterations in migraineurs. As the function of the human brain is related to its structure, we further investigated white and gray matter structural alterations in migraineurs.MethodsIn current study, we used surface-based morphometry, voxel-based morphometry and diffusion tensor imaging analyses to detect structural alterations of the white matter and gray matter in 32 migraineurs without aura compared with 32 age- and gender-matched healthy controls.ResultsWe found that migraineurs without aura exhibited significantly increased gray matter volume in the bilateral cerebellar culmen, increased cortical thickness in the lateral occipital-temporal cortex, decreased cortical thickness in the right insula, increased gyrification index in left postcentral gyrus, superior parietal lobule and right lateral occipital cortex, and decreased gyrification index in the left rostral middle frontal gyrus compared with controls. No significant change in white matter microstructure was found in DTI analyses.ConclusionThe significantly altered gray matter brain regions were known to be associated with sensory discrimination of pain, multi-sensory integration and nociceptive information processing and were consistent with our previous fMRI study, and may be involved in the pathological mechanism of migraine without aura.

FUNCTIONAL NETWORK FOR BASIC, INSTRUMENTAL AND ADVANCED IADL IN ALZHEIMER'S DISEASES: THE TECHNOLOGY-ACTIVITIES OF DAILY LIVING QUESTIONNAIRE

Information and communication technology (ICT) has become an increasingly important part of daily life. The Technology–Activities of Daily Living Questionnaire (T-ADLQ): is a novel functional assessment scale that incorporates an ICT-related subscale. The assessment of functionality is an essential item in the diagnosis of dementia due to Alzheimer's Disease (AD). T-ADLQ allow to divided ADL in three domains, i.e. Basic Activities of Daily Living (BADLs), Instrumental Activities of Daily Living (IADLs) and Advanced ADL (a-ADL). There is limited research about AD-related neural change leading to decreased independence and no study investigating the neural correlates of a-ADL and the differences that could existwith BADL and IADL Objective: Explore the neural correlates of the global score of the T-ADQL and the three domains of ADL in patients with AD in comparison to healthy controls (HC). MR images were obtained with a 1.5-Tesla magnetic resonance scanner, T-1-weighted. The T-ADLQ were covaried against gray matter atrophy regions via Voxel-based morphometry in AD (n=33) and contrasted against Healthy Controls (n=29). The study was approved by the Ethical and Scientific Committee-SSMO. The T-ADLQ, controlled for age and education level, correlated with prefrontal, inferior and medial temporal lobe, as well as occipital brain regions in particular, indicating the importance of those regions in performing ADL type activities. BADL, IADL and a-ADL shares neuroanatomical commonalities and differences. Our study suggests that widespread atrophy of the prefrontal, temporal and occipital brain regions is significantly associated with functional impairment and cifferent domain of ADL are subtended by difference neural network- These findings further corroborate the notion that functional impairments are very sensitive to neurodegenerative processes, as they require intactness of multiple brain regions. Fundings: CONICYT / FONDAP /15150012; Conicyt/ Fondecyt Regular/ 1140423 and Basal Funds for Centers of Excellence, Project FB 0003 from the Associative Research Program of CONICYT.

RESTING STATE NETWORK MODULARITY ALONG THE PRODROMAL LATE ONSET ALZHEIMER’S DISEASE CONTINUUM

Alzheimer's disease (AD) results in a disconnection syndrome that can be reliably detected using whole-brain functional connectivity (FC) network analyses. We used multiscale modularity analysis [1] of resting state fMRI (rsfMRI) data to investigate changes in connectivity among resting state networks (RSNs) across four different stages in the AD continuum. Participants included 78 older adults from the Indiana Memory and Aging Study (22-subjective cognitive decline (SCD), 16-MCI, 13-AD, and 29-cognitively normal (CN) controls). All underwent rsfMRI preprocessed using an in-house pipeline. For each participant, FC was expressed as a matrix of Pearson correlations between pairs of time series from 278 gray matter brain regions [2]. To assess community structure across multiple scales, we systematically varied the resolution parameter γ and optimized a modularity metric at each scale. Consensus solutions were aggregated across all values of γ to derive a multi-scale co-assignment matrix. Modules were compared to a standard RSNs partition [3] with subcortical and cerebellar regions added for a total of nine networks. Additionally, the average density of FC within and between RSNs was calculated for each group providing four 9x9 matrices (containing 45 sub-blocks). Significant sub-blocks were further analyzed using linear correlation regression models against average memory, executive function, executive function with language, and general cognition scores. Age, sex, and education were treated as nuisance variables. Retained sub-blocks were determined with the following dual criteria: The block must have achieved p<0.01 for both FC and module cluster co-assignment. Modularity analysis revealed that connections between the frontoparietal attention (FP) and default mode (DMN) RSNs varied systematically with diagnosis (Figure 1). Additionally, linear regression analysis revealed negative correlations between all cognitive domains and average FC between DMN and FP networks.