Changes In Functional Patterns Research Articles

Abnormal Interhemispheric Functional Connectivity in Acute Pericoronitis: A Resting-State MRI Study.

Acute pericoronitis (AP) is a prevalent cause of odontogenic toothache which can significantly impact brain function. Previous research has predominantly concentrated on localized brain activity. However, the synergistic changes between brain hemispheres induced by toothache and resulting abnormal functional connectivity across the brain have not been comprehensively studied. A total of 34 patients with AP and 34 healthy individuals, matched for age, sex, and education were recruited for this study. All participants underwent resting-state functional magnetic resonance imaging (rs-MRI) scans. The voxel mirror homotopic connectivity (VMHC) method was used to identify intergroup differences. Brain regions exhibiting statistically significant differences were selected as regions of interest for further functional connectivity analysis. The partial correlation method was utilized to assess the correlation between abnormal VMHC values in different regions and clinical parameters, with age and sex included as covariates. Patients with AP exhibited reduced VMHC values in the thalamus and elevated VMHC values in the inferior frontal gyrus compared with healthy controls. Subsequent functional connectivity analyses revealed extensive changes in functional networks, predominantly affecting the default, frontoparietal, cerebellar, and pain networks. Changes in functional patterns across these brain networks offer novel insights into the neurophysiological mechanisms underlying pain information processing.

Use of hyperboloid as an adjunct in functional jaw orthopedics – case report

Anterior open bite can be defined as a malocclusion with a negative vertical discrepancy between the incisal edges of the upper and lower anterior teeth, which do not have occlusal contacts with the antagonists and sometimes extends to the canines and, less frequently, to the premolars is one of the malocclusions with the greatest aesthetic and/or functional impairment. Anterior open bite can have several etiologies: finger sucking and/or pacifier, oral breathing, onychophagia, lip interposition, atypical swallowing, tongue interposition when uttering phonemes and anterior posture of the tongue at rest. Orofacial myofunctional disorders are present in cases of anterior open bite, generally associated with etiologies and adapt to this altered morphological condition. Regarding the anterior opening amplitude, the anterior open bite is classified as: minimum up to 1 mm, moderate between 1 and 5 mm and severe +5 mm [1]. Open bite can be classified into: maxillary, mandibular and hybrid open bite [2]. Myofunctional therapy is considered a treatment method that can increase muscle strength, cause changes in functional patterns and thus prevent deviations in craniofacial development, as it promotes new posture of structures at rest and during the performance of the functions of the stomatognathic system [3]. The hyperboloid is an instrument for increasing muscle tone and when used in chewing, it is efficient in inducing growth and remodeling. The hyperboloid fills a gap in the modern diet, with the consistency of hard, raw and dry foods [4]. Exercises with a size M hyperboloid with wire were prescribed as an initial approach. After 2 months of treatment, there was an improvement in the interincisor distance. The exercise was maintained for another 5 months. He stopped attending appointments for 2 years and 2 months. Upon his return, the results of the functional examination of swallowing, chewing, protrusion and laterality were observed, and we opted for the installation of the SN3. the hyperboloid, in this case, showed its efficiency in balancing the stomatognathic system.

Graded and sharp transitions in semantic function in left temporal lobe

Recent work has focussed on how patterns of functional change within the temporal lobe relate to whole-brain dimensions of intrinsic connectivity variation (Margulies et al., 2016). We examined two such ‘connectivity gradients’ reflecting the separation of (i) unimodal versus heteromodal and (ii) visual versus auditory-motor cortex, examining visually presented verbal associative and feature judgments, plus picture-based context and emotion generation. Functional responses along the first dimension sometimes showed graded change between modality-tuned and heteromodal cortex (in the verbal matching task), and other times showed sharp functional transitions, with deactivation at the extremes and activation in the middle of this gradient (internal generation). The second gradient revealed more visual than auditory-motor activation, regardless of content (associative, feature, context, emotion) or task process (matching/generation). We also uncovered subtle differences across each gradient for content type, which predominantly manifested as differences in relative magnitude of activation or deactivation.

Functional changes in the salience network of patients with amnesic mild cognitive impairment before and after repetitive transcranial magnetic stimulation.

Amnestic mild cognitive impairment (aMCI) is considered to be the prodromal stage of Alzheimer's disease (AD). The precuneus (PCUN) may be an imaging marker for monitoring the progression of AD. Meanwhile, cognitive impairment in AD patients is closely related to functional connectivity (FC) changes in the salience network (SN). We hypothesize that there are specific neuroimaging biomarkers in the SN and that FC changes in aMCI patients after repetitive transcranial magnetic stimulation (rTMS) intervention are associated with cognitive function. The purpose of this study was to first investigate the pattern of functional changes in aMCI patients and healthy controls (HCs) and then compare the functional changes in aMCI patients before and after rTMS targeting to PCUN and its correlation with cognitive function. Thirty-six HCs and 61 aMCIs were recruited for our study. Eleven people in the aMCI group received rTMS intervention 5 days a week for 4 weeks. Using the right anterior insula as the seed-of-interest, we first compared FC changes in HC and aMCI patients and then compared cognitive function in aMCI patients before and after rTMS. The above is the functional connection analysis of seed-to-voxel. Moreover, we investigated the FC changes in aMCI patients after rTMS intervention and its correlation with cognitive function. Compared with HC, the aMCI group showed altered FC in bilateral parahippocampal gyrus, bilateral inferior parietal lobule, left middle frontal gyrus, and left middle temporal gyrus. Moreover, rTMS at PCUN improved the cognitive function of aMCI patients, which was related to the altered FC in posterior cerebellar lobes (CPL). Our findings suggest that rTMS targeting PCUN is a promising, noninvasive approach to ameliorating cognitive dysfunction in aMCI patients, and that this cognitive improvement is accompanied by brain connectivity modulation.

Effects of nitrofurazone on ecosystem function in marine environments: A case study on microbial fauna.

To evaluate the effects of nitrofurazone on functional processes in marine ecosystems, periphytic protozoan communities were exposed to different concentrations of the antibiotic for a 10-day duration. Species trait distributions in the tested communities were observed during exposure to five concentrations of nitrofurazone. A fuzzy coding system with seven traits and seventeen categories was used to summarize the changes in functional patterns of the test organisms. Nitrofurazone had a significant influence on the function process of the periphytic ciliate communities. Bacterivores with flattened bodies were sensitive to the toxicant whereas sessile and cylindrical raptors showed a high tolerance to nitrofurazone, invariably dominating communities exposed to high concentrations. Bootstrapped-average analysis demonstrated a significant change in functional patterns at highest nitrofurazone concentrations (8mgl-1). Based on these findings, it is suggested that nitrofurazone may negatively influence ecosystem function in marine environments.

Challenging functional connectivity data: machine learning application on essential tremor recognition.

This paper aimed to investigate the usefulness of applying machine learning on resting-state fMRI connectivity data to recognize the pattern of functional changes in essential tremor (ET), a disease characterized by slight brain abnormalities, often difficult to detect using univariate analysis. We trained a support vector machine with a radial kernel on the mean signals extracted by 14 brain networks obtained from resting-state fMRI scans of 18 ET and 19 healthy control (CTRL) subjects. Classification performance between pathological and control subjects was evaluated using a tenfold cross-validation. Recursive feature elimination was performed to rank the importance of the extracted features. Moreover, univariate analysis using Mann-Whitney U test was also performed. The machine learning algorithm achieved an AUC of 0.75, with four networks (language, primary visual, cerebellum, and attention), which have an essential role in ET pathophysiology, being selected as the most important features for classification. By contrast, the univariate analysis was not able to find significant results among these two conditions. The machine learning approach identifies the changes in functional connectivity of ET patients, representing a promising instrument to discriminate specific pathological conditions and find novel functional biomarkers in resting-state fMRI studies.

LONG-TERM EFFECTS OF SHAM SURGERY ON PHAGOCYTE FUNCTIONS IN RATS

Animal models of inflammatory disorders, including those of the nervous system are commonly used to explore the pathophysiological role of immune cell response in disease triggering and course and to develop biotechnology products for therapeutic use. Modeling some of these disorders, particularly neurodegenerative diseases, implies surgical manipulations for the intracerebral introduction of disease-initiating substances (toxins, amyloids etc.). Design of these experiments involves the use of sham-operated animals as a control of non-specific intrinsic side-effects elicited by surgical manipulations per se, including local and systemic inflammation, where phagocytic cells are key participants. Short-term post-surgical immunomodulatory effects are widely reported. However, no study thus far has examined the long term effects of sham-surgery on phagocyte functions. The purpose of this study was to evaluate the effect of sham-surgery, commonly used for modeling neurodegenerative diseases, on phagocyte functions in the far terms after the surgical manipulations. Materials and Methods. Adult male Wistar rats were used in the study. Sham surgery consisted of stereotactic unilateral injection of saline solution into the median forebrain bundle (sham-operated 1, SO1) or directly into the substantia nigra (sham-operated 2, SO2). Before the placebo surgery, animals were anaesthetized using nembutal and ketamine/xylazine correspondingly. Functional characteristics (phagocytic activity, oxidative metabolism, CD80/86 and CD206 expression) of phagocytes (microglia, peritoneal macrophages, circulating monocytes and granulocytes) were examined by flow cytometry. Differential leukocyte count was conducted using hematological analyzer. Results. Phagocytes from animals underwent of different protocols of placebo surgery, demonstrated various patterns of functional changes on day 29 after the manipulations. In animals from SO1 group, we observed signs of residual neuroinflammation (pro-inflammatory shift of microglia functional profile) along with ongoing resolution of systemic inflammation (anti-inflammatory metabolic shift of circulating phagocytes and peritoneal macrophages). In rats from SO2 group, pro-inflammatory polarized activation of peritoneal phagocytes was registered along with anti-inflammatory shift in microglia and circulating phagocytes. Conclusions. Sham surgery influences functions of phagocytic cells of different locations even in the far terms after the manipulations. These effects can be considered as combined long-term consequences of surgical brain injury and the use of anesthetics. Our observations evidences, that sham associated non-specific immunomodulatory effects should always be taken into consideration in animal models of inflammatory central nervous system diseases.

Characterization of Immune Phenotypes in Peripheral Blood of Adult Renal Transplant Recipients using Mass Cytometry (CyTOF)

Abstract Background Chronic immunosuppressive therapy in transplant patients can be associated with opportunistic infections and risks of cancer development. There is an important need to better measure the immune status of patients in a transplant setting to improve patient monitoring and guide development of appropriate immunosuppressive agents and regimen. Results In this study, CyTOF was performed to comprehensively characterize the immune differences between 10 renal transplant recipients and 11 age-matched healthy donors, longitudinally over 6 months. Overall, the immune cells of transplant patients showed signs of increased CD8+ T cell activation/differentiation. Higher levels of CD57 on CD8+ T cells were observed. CD8+ T cells and their memory subsets also showed increased production of MIP-1β and IFNγ. Further, CD107a and Granzyme B expression were also increased in CD8+ T cells and CD56hi NK cells, while Tregs had decreased IL-10 production. These changes are consistent with a more stimulated immune system, despite the administration of immune suppressants to the patients. However, there were also some signs of immune suppression in the transplant patients consistent with the treatment regimen. γδT cells showed decreased TNFα and IFNγ expression, while MIP-1β expression was reduced in NKT, CD56hi NK and γδT cells. CD8+ T memory cell subsets also showed decreased expression of IL-2, IL-17 and GM-CSF. Conclusions This mosaic pattern of functional changes highlights the importance of comprehensive immune monitoring of these patients. Such information will aid in optimizing individual treatment strategies and development of improved immunosuppressants that specifically target overly activated populations.

Dynamic of functional parameters of cardio-vascular system in patients with vertebrogenic pathology after body position changes

Postural hemodynamic reactions are well-known but their dependency on anthropometrics is still not fully studied. A significant amount of surgeries are provided in prone position, so it is important for anesthesiologist to predict specific physiologic changes.Objectives: to study patterns of functional changes in cardiovascular system in patients with vertebrogenic pathology after turning from supine to prone position and the influence of age and body mass index on them.Material and methods: we examined 200 patients of 18–75 y. o.; 118 male and 82 female. In group І there were patients with body mass index ≤ 25 kg/m2 and in group ІІ – patients with body mass index > 25 kg/m2 . Hemodynamics were examined by thoracic rheography in supine position, in prone position 5 min after turning and in prone position 20 min after turning.Results: in patients of group ІІ vs patients of group A we foundnd significantly higher level of systolic BP in 5 min and 20 min after turning to prone position, and diastolic BP, mean BP and peripheral vascular resistance at all stages of study. Stroke volume index and cardiac index were significantly lower at all stages of studied patients of group ІІ. After turning into prone position diastolic BP and peripheral vascular resistance increased by 15,2 % in all patients, but in patients with body mass index > 25 kg/m2 it did not reverse to basal level. Cardiac index changed only in patients of group ІІ. Stroke volume index decreased by 13,6 % in all patients, but in 20 min it became normal only in patients of group І and was low in patients of group ІІ.Conclusions: compensatory reaction of cardiovascular system after turning to prone position depended on age and body mass index. Dependence on body mass index is more significant and anesthesiologist should be aware of these changes when planning anesthesia in prone position.

Functional MRI of disease progression in Parkinson disease and atypical parkinsonian syndromes.

To explore longitudinal changes in brain activity in patients with Parkinson disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP) using task-based functional MRI (fMRI). A total of 112 individuals were scanned 1 year apart while performing a unimanual grip force task: 46 PD, 13 MSA, 19 PSP, and 34 healthy controls. The outcome measure was percent signal change in prespecified regions of interest: putamen, primary motor cortex (M1), supplementary motor area (SMA), and superior motor regions of the cerebellum (lobules V-VI). Patients with PD showed a decline in functional activity over the course of 1 year in the putamen and M1 compared to controls. Changes after 1 year in MSA were exclusively extrastriatal, and included a reduction in functional activity in M1, SMA, and superior cerebellum. In PSP, all regions of interest were less active at 1 year compared to baseline. The functional activity of these regions did not change in the control group. We provide evidence using task-based fMRI for cortical and striatal functional deterioration in PD over a 1-year period of time. Results also describe more widespread and unique patterns of functional changes in MSA and PSP compared to PD, suggesting distinct rates of disease progression in parkinsonian disorders that may assist in future clinical studies testing the potential efficacy of disease-modifying therapies.

Training of verbal creativity modulates brain activity in regions associated with language- and memory-related demands.

This functional magnetic resonance (fMRI) study was designed to investigate changes in functional patterns of brain activity during creative ideation as a result of a computerized, 3‐week verbal creativity training. The training was composed of various verbal divergent thinking exercises requiring participants to train approximately 20 min per day. Fifty‐three participants were tested three times (psychometric tests and fMRI assessment) with an intertest‐interval of 4 weeks each. Participants were randomly assigned to two different training groups, which received the training time‐delayed: The first training group was trained between the first and the second test, while the second group accomplished the training between the second and the third test session. At the behavioral level, only one training group showed improvements in different facets of verbal creativity right after the training. Yet, functional patterns of brain activity during creative ideation were strikingly similar across both training groups. Whole‐brain voxel‐wise analyses (along with supplementary region of interest analyses) revealed that the training was associated with activity changes in well‐known creativity‐related brain regions such as the left inferior parietal cortex and the left middle temporal gyrus, which have been shown as being particularly sensitive to the originality facet of creativity in previous research. Taken together, this study demonstrates that continuous engagement in a specific complex cognitive task like divergent thinking is associated with reliable changes of activity patterns in relevant brain areas, suggesting more effective search, retrieval, and integration from internal memory representations as a result of the training. Hum Brain Mapp 36:4104–4115, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

One Year Follow-up of Functional Recovery in Neovascular AMD During Monthly Anti-VEGF Treatment

To identify neurosensory recovery, testing different functional variables during monthly intravitreal standard anti-vascular endothelial growth factor (VEGF) therapy in neovascular age-related macular degeneration (AMD). Prospective interventional cohort study. Sixty-four treatment-naïve neovascular AMD patients with subfoveal lesions were treated and examined monthly for distance visual acuity, reading acuity, maximum reading speed, and contrast sensitivity and with microperimetry evaluating the percentage of absolute and relative scotoma and mean central retinal sensitivity weighted by area. Improvements in reading acuity, distance acuity, reading speed, contrast sensitivity, mean central retinal sensitivity, and scotoma area in dependence of age, lesion type, lesion size, and mean central retinal sensitivity were evaluated by a random-slope and random-intercept model. Recovery pattern of parameters was compared by correlating the individual slopes of each variable. Initially, a rapid short-term effect of anti-VEGF treatment was documented throughout all functional variables. Progressive functional gain over 1 year was observed for distance visual acuity (P = .011), contrast sensitivity (P ≤ .0001), and mean central retinal sensitivity (P ≤ .0001), but not for reading acuity (P = .31) and maximum reading speed (P = .94). Decrease of absolute scotoma area missed statistical significance over time (P = .053) and also fixation stability did not improve (P = .08). However, lesion size influenced the course of absolute scotoma area (P = .0015), while lesion type had no effect on any visual function variable evaluated. The individual slopes of reading acuity and distance visual acuity showed a moderate correlation; however, all other variables showed only a weak or no significant correlation among each other. Visual recovery in anti-VEGF therapy is reflected in a characteristic pattern of functional changes over time, whereas distance visual acuity does not seem to comprehensively reflect overall visual function gain.

FORUM: Sustaining ecosystem functions in a changing world: a call for an integrated approach

Summary With ever‐increasing human pressure on ecosystems, it is critically important to predict how ecosystem functions will respond to such human‐induced perturbations. We define perturbations as either changes to abiotic environment (e.g. eutrophication, climate change) that indirectly affects biota, or direct changes to biota (e.g. species introductions). While two lines of research in ecology, biodiversity–ecosystem function (BDEF) and ecological resilience (ER) research, have addressed this issue, both fields of research have nontrivial shortcomings in their abilities to address a wide range of realistic scenarios. We outline how an integrated research framework may foster a deeper understanding of the functional consequences of perturbations via simultaneous application of (i) process‐based mechanistic predictions using trait‐based approaches and (ii) detection of empirical patterns of functional changes along real perturbation gradients. In this context, the complexities of ecological interactions and evolutionary perspectives should be integrated into future research. Synthesis and applications. Management of human‐impacted ecosystems can be guided most directly by understanding the response of ecosystem functions to controllable perturbations. In particular, we need to characterize the form of a wide range of perturbation–function relationships and to draw connections between those patterns and the underlying ecological processes. We anticipate that the integrated perspectives will also be helpful for managers to derive practical implications for management from academic literature.

Functional network connectivity in the behavioral variant of frontotemporal dementia

IntroductionThe aim of this study was to investigate, using resting state (RS) functional magnetic resonance imaging (fMRI), the functional connectivity within and among brain networks in patients with the behavioral variant of frontotemporal dementia (bvFTD), compared with healthy controls and patients with probable Alzheimer's disease (pAD). MethodsTwelve bvFTD patients were compared with 30 controls and 18 pAD patients. Functional connectivity within the salience, default mode (DMN), executive (EXN), attention/working memory (ATT/WM), and dorsal attentional networks was assessed using independent component analysis. The temporal associations among RS networks (RSNs) were explored using the functional network connectivity toolbox. ResultsA decreased dorsal salience network (DSN) connectivity, mainly involving the anterior cingulum, was observed in bvFTD versus controls and pAD. BvFTD was also characterized by a decreased ventral salience network connectivity in the basal ganglia, and divergent connectivity effects versus controls in the dorsolateral prefrontal cortex (decreased) and precuneus (enhanced) within the right ATT/WM network. The dorsal attentional network had a decreased connectivity with the DMN and EXN in bvFTD versus controls, and a decreased connectivity with the DSN versus pAD. ConclusionsRSN functional abnormalities occur in bvFTD, involving not only the salience network, but also the DMN and fronto-parietal network associated with ATT and WM modulation. The pattern of functional changes differs from that seen in pAD. The altered interactions among RSN observed in bvFTD and pAD may provide a new venue to explore the functional correlates of cognitive abnormalities in neurodegenerative and psychiatric disorders.

Functional immaturity of cortico-basal ganglia networks in Gilles de la Tourette syndrome

Gilles de la Tourette syndrome is a clinically heterogeneous disorder with poor known pathophysiology. Recent neuropathological and structural neuroimaging data pointed to the dysfunction of cortico-basal ganglia networks. Nonetheless, it is not clear how these structural changes alter the functional activity of the brain and lead to heterogeneous clinical expressions of the syndrome. The objective of this study was to evaluate global integrative state and organization of functional connections of sensori-motor, associative and limbic cortico-basal ganglia networks, which are likely involved in tics and behavioural expressions of Gilles de la Tourette syndrome. We also tested the hypothesis that specific regions and networks contribute to different symptoms. Data were acquired on 59 adult patients and 27 gender- and age-matched controls using a 3T magnetic resonance imaging scanner. Cortico-basal ganglia networks were constructed from 91 regions of interest. Functional connectivity was quantified using global integration and graph theory measures. We found a stronger functional integration (more interactions among anatomical regions) and a global functional disorganization of cortico-basal ganglia networks in patients with Gilles de la Tourette syndrome compared with controls. All networks were characterized by a shorter path length, a higher number of and stronger functional connections among the regions and by a loss of pivotal regions of information transfer (hubs). The functional abnormalities correlated to tic severity in all cortico-basal ganglia networks, namely in premotor, sensori-motor, parietal and cingulate cortices and medial thalamus. Tic complexity was correlated to functional abnormalities in sensori-motor and associative networks, namely in insula and putamen. Severity of obsessive-compulsive disorder was correlated with functional abnormalities in associative and limbic networks, namely in orbito-frontal and prefrontal dorsolateral cortices. The results suggest that the pattern of functional changes in cortico-basal ganglia networks in patients could reflect a defect in brain maturation. They also support the hypothesis that distinct regions of cortico-basal ganglia networks contribute to the clinical heterogeneity of this syndrome.

Brain functional changes (QEEG cordance) and worsening suicidal ideation and mood symptoms during antidepressant treatment

Antidepressant medications are efficacious overall; however, some individuals experience worsening mood symptoms and increased suicidal ideation (SI) during treatment. We examined the quantitative electroencephalographic (QEEG) cordance biomarker of brain function biomarker in relation to treatment-emergent symptom worsening. Seventy-two major depressive disorder (MDD) subjects were treated with fluoxetine 20 mg (n = 13), venlafaxine 150 mg (n = 24), or placebo (n = 35) under double-blind conditions. Behavioral ratings determined whether each subject demonstrated worsening of depressed mood, anxiety, or SI during treatment. QEEG cordance data were analyzed to determine whether symptom worsening was associated with neurophysiological changes. Antidepressant treatment-emergent SI (13.5%) was associated with a large transient decrease in midline-and-right-frontal (MRF) cordance 48 h after start of medication. Hypothesis-generating results suggest a pattern of functional changes in midline and right frontal brain regions associated with antidepressant treatment-emergent SI in MDD.

Region-specific changes in prefrontal function with age: a review of PET and fMRI studies on working and episodic memory

Several neuroimaging studies of cognitive ageing have found that age-related deficits in working memory (WM) and episodic memory abilities are related to changes in prefrontal cortex (PFC) function. Reviews of these neuroimaging studies have generally concluded that with age there is a reduction in the hemispheric specialization of cognitive function in the frontal lobes that may either be due to dedifferentiation of function, deficits in function and/or functional reorganization and compensation. Moreover, previous reviews have considered the PFC as homogeneous in function and have not taken into account the possibility that region specific changes in PFC function may occur with age. In the current review we performed a qualitative meta-analytic review of all the functional magnetic resonance imaging ageing studies and positron emission tomography ageing studies of WM and episodic memory that report PFC activation, to determine if any region-specific changes occur. The results indicated that in normal ageing distinct PFC regions exhibit different patterns of functional change, suggesting that age-related changes in PFC function are not homogeneous in nature. Specifically, we hypothesize that normal ageing is related to the differentiation of cortical function in a bilateral ventral PFC and deficits in function in right dorsal and anterior PFC. As a result of these changes, functional compensation in left dorsal and anterior PFC may occur. We hope that future studies will be conducted to either confirm or counter these hypotheses.

Pattern of cortical reorganization in amyotrophic lateral sclerosis: a functional magnetic resonance imaging study.

Depending on individual lesion location and extent, reorganization of the human motor system has been observed with a high interindividual variability. In addition, variability of forces exerted, of motor effort, and of movement strategies complicates the interpretation of functional imaging studies. We hypothesize that a general pattern of reorganization can be identified if a homogeneous patient population is chosen and experimental conditions are controlled. Patients with amyotrophic lateral sclerosis (ALS) and healthy volunteers were trained to perform a simple finger flexion task with 10% of each individual's maximum grip force with constant movement amplitude and frequency. The activation pattern in ALS patients was distinctly different to that in healthy controls: In ALS patients, motor cortex activation was located more anteriorly, encompassing the premotor gyrus. The cluster volume within the supplementary motor area (SMA) was higher and shifted toward the pre-SMA. Contralateral inferior area 6 and bilateral parietal area 40 revealed higher cluster volumes. Our results demonstrate a general pattern of functional changes after motor neuron degeneration. They support the concept of a structurally parallel and functionally specialized organization of voluntary motor control. Degeneration of the first and second motor neurons leads to enhanced recruitment of motor areas usually involved in initiation and planning of movement. Partial compensation between functionally related motor areas seems to be a strategy to optimize performance if the most efficient pathway is unavailable.

Differential effects of cocaine on local cerebral glucose utilization in the mouse and in the rat

The aim of the study was to determine whether cocaine causes a different pattern of functional changes in the rat as compared to the mouse. The [ 14C]2-deoxyglucose method, for measuring local cerebral metabolic rates for glucose, was carried out in Sprague–Dawley rats and in two strains of mice, C57BL/6 and DBA/2, following a single intravenous administration of cocaine. Cocaine, according to previous reports, increased glucose utilization in the nucleus accumbens of the rat, while the drug decreased metabolic rates in most of brain areas of both strains of mice. The post-hoc analysis, however, suggests that the pattern of metabolic changes differ in the two strains. In particular, the effect on the shell of the nucleus accumbens was present in the C57, but not in the DBA mice. As the C57 mice are more likely than DBA to initiate cocaine self-administration, the effect on the nucleus accumbens support the role of the mesolimbic pathway in mediating the motivational properties of psychostimulants.

Predictors of functional status in older people living at home.

to describe changes in functional status of community-dwelling Spanish elderly people, followed for 2 years, and to identify socio-demographic and health characteristics that predict functional change. we have analysed data from the first two waves of the longitudinal study, Ageing in Leganés, from a representative sample of community-dwelling people aged 65 and over (n=1273). Functional status was categorized according to a hierarchical scale as: completely functional, with functional limitations, with instrumental activities of daily living (IADL) disability, with activities of daily living (ADL) disability or deceased. Multinomial logistic regression was used to estimate the predictive value of selected 1993 socio-demographic and health status variables on 1995 functional status. prevalence of disability based on dependency in any of seven ADL items was 15.5%. Half of the respondents were disabled in at least one of 10 IADLs. Some improved functionally, others deteriorated. Men were more likely to recover function while women were more likely to enter and to remain in the IADL state. Socioeconomic factors were associated to baseline functional status and to functional status change on bivariate analysis. Number of chronic diseases, presence of cognitive problems and depressive symptoms predicted transitions, even after controlling for baseline functional status. although estimates of prevalence of disability among people over 65 are higher in Spain than in other European and North American countries, the pattern of functional changes, both in the direction of improvement and decline, seems to be similar.