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832 result(s) for "Precentral gyrus"
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A somato-cognitive action network alternates with effector regions in motor cortex
Motor cortex (M1) has been thought to form a continuous somatotopic homunculus extending down the precentral gyrus from foot to face representations 1 , 2 , despite evidence for concentric functional zones 3 and maps of complex actions 4 . Here, using precision functional magnetic resonance imaging (fMRI) methods, we find that the classic homunculus is interrupted by regions with distinct connectivity, structure and function, alternating with effector-specific (foot, hand and mouth) areas. These inter-effector regions exhibit decreased cortical thickness and strong functional connectivity to each other, as well as to the cingulo-opercular network (CON), critical for action 5 and physiological control 6 , arousal 7 , errors 8 and pain 9 . This interdigitation of action control-linked and motor effector regions was verified in the three largest fMRI datasets. Macaque and pediatric (newborn, infant and child) precision fMRI suggested cross-species homologues and developmental precursors of the inter-effector system. A battery of motor and action fMRI tasks documented concentric effector somatotopies, separated by the CON-linked inter-effector regions. The inter-effectors lacked movement specificity and co-activated during action planning (coordination of hands and feet) and axial body movement (such as of the abdomen or eyebrows). These results, together with previous studies demonstrating stimulation-evoked complex actions 4 and connectivity to internal organs 10 such as the adrenal medulla, suggest that M1 is punctuated by a system for whole-body action planning, the somato-cognitive action network (SCAN). In M1, two parallel systems intertwine, forming an integrate–isolate pattern: effector-specific regions (foot, hand and mouth) for isolating fine motor control and the SCAN for integrating goals, physiology and body movement. Functional MRI studies across ages show that the classic homunculus of the motor cortex in humans is in fact discontinuous, alternating with action control-linked regions termed the somato-cognitive action network.
An Accurate and Rapidly Calibrating Speech Neuroprosthesis
In a man with impaired speech from amyotrophic lateral sclerosis, an intracortical speech neuroprosthesis achieved more than 97% accuracy in decoding his intended speech and making it audible in his natural voice.
Hyperbaric oxygen therapy improves neurocognitive functions and symptoms of post-COVID condition: randomized controlled trial
Post-COVID-19 condition refers to a range of persisting physical, neurocognitive, and neuropsychological symptoms after SARS-CoV-2 infection. The mechanism can be related to brain tissue pathology caused by virus invasion or indirectly by neuroinflammation and hypercoagulability. This randomized, sham-control, double blind trial evaluated the effect of hyperbaric oxygen therapy (HBOT or HBO2 therapy) on post-COVID-19 patients with ongoing symptoms for at least 3 months after confirmed infection. Seventy-three patients were randomized to receive daily 40 session of HBOT (n = 37) or sham (n = 36). Follow-up assessments were performed at baseline and 1–3 weeks after the last treatment session. Following HBOT, there was a significant group-by-time interaction in global cognitive function, attention and executive function (d = 0.495, p = 0.038; d = 0.477, p = 0.04 and d = 0.463, p = 0.05 respectively). Significant improvement was also demonstrated in the energy domain (d = 0.522, p = 0.029), sleep (d = − 0.48, p = 0.042), psychiatric symptoms (d = 0.636, p = 0.008), and pain interference (d = 0.737, p = 0.001). Clinical outcomes were associated with significant improvement in brain MRI perfusion and microstructural changes in the supramarginal gyrus, left supplementary motor area, right insula, left frontal precentral gyrus, right middle frontal gyrus, and superior corona radiate. These results indicate that HBOT can induce neuroplasticity and improve cognitive, psychiatric, fatigue, sleep and pain symptoms of patients suffering from post-COVID-19 condition. HBOT’s beneficial effect may be attributed to increased brain perfusion and neuroplasticity in regions associated with cognitive and emotional roles.
Recruitment of the motor system during music listening: An ALE meta-analysis of fMRI data
Several neuroimaging studies have shown that listening to music activates brain regions that reside in the motor system, even when there is no overt movement. However, many of these studies report the activation of varying motor system areas that include the primary motor cortex, supplementary motor area, dorsal and ventral pre-motor areas and parietal regions. In order to examine what specific roles are played by various motor regions during music perception, we used activation likelihood estimation (ALE) to conduct a meta-analysis of neuroimaging literature on passive music listening. After extensive search of the literature, 42 studies were analyzed resulting in a total of 386 unique subjects contributing 694 activation foci in total. As suspected, auditory activations were found in the bilateral superior temporal gyrus, transverse temporal gyrus, insula, pyramis, bilateral precentral gyrus, and bilateral medial frontal gyrus. We also saw the widespread activation of motor networks including left and right lateral premotor cortex, right primary motor cortex, and the left cerebellum. These results suggest a central role of the motor system in music and rhythm perception. We discuss these findings in the context of the Action Simulation for Auditory Prediction (ASAP) model and other predictive coding accounts of brain function.
Neurofunctional mapping of reward anticipation and outcome for major depressive disorder: a voxel-based meta-analysis
Aberrations in how people form expectations about rewards and how they respond to receiving rewards are thought to underlie major depressive disorder (MDD). However, the underlying mechanism linking the appetitive reward system, specifically anticipation and outcome, is still not fully understood. To examine the neural correlates of monetary anticipation and outcome in currently depressed subjects with MDD, we performed two separate voxel-wise meta-analyses of functional neuroimaging studies using the monetary incentive delay task. During reward anticipation, the depressed patients exhibited an increased response in the bilateral middle cingulate cortex (MCC) extending to the anterior cingulate cortex, the medial prefrontal cortex, the left inferior frontal gyrus (IFG), and the postcentral gyrus, but a reduced response in the mesolimbic circuit, including the left striatum, insula, amygdala, right cerebellum, striatum, and IFG, compared to controls. During the outcome stage, MDD showed higher activity in the left inferior temporal gyrus, and lower activity in the mesocortical pathway, including the bilateral MCC, left caudate nucleus, precentral gyrus, thalamus, cerebellum, right striatum, insula, IFG, middle frontal gyrus, and temporal pole. Our findings suggest that cMDD may be characterised by state-dependent hyper-responsivity in cortical regions during the anticipation phase, and hypo-responsivity of the mesocortico-limbic circuit across the two phases of the reward response. Our study showed dissociable neural circuit responses to monetary stimuli during reward anticipation and outcome, which help to understand the dysfunction in different aspects of reward processing, particularly motivational v. hedonic deficits in depression.
Brain Neuroplasticity Related to Lateral Ankle Ligamentous Injuries: A Systematic Review
Background Lateral ankle sprains are the most common ankle injuries in sports and have the highest recurrence rates. Almost half of the patients experiencing lateral ankle sprains develop chronic ankle instability. Patients with chronic ankle instability experience persistent ankle dysfunctions and detrimental long-term sequelae. Changes at the brain level are put forward to explain these undesirable consequences and high recurrence rates partially. However, an overview of possible brain adaptations related to lateral ankle sprains and chronic ankle instability is currently lacking. Objective The primary purpose of this systematic review is to provide a comprehensive overview of the literature on structural and functional brain adaptations related to lateral ankle sprains and in patients with chronic ankle instability. Methods PubMed, Web of Science, Scopus, Embase, EBSCO—SPORTDiscus and Cochrane Central Register of Controlled Trials were systematically searched until 14 December, 2022. Meta-analyses, systematic reviews and narrative reviews were excluded. Included studies investigated functional or structural brain adaptations in patients who experienced a lateral ankle sprain or with chronic ankle instability and who were at least 18 years of age. Lateral ankle sprains and chronic ankle instability were defined following the recommendation of the International Ankle Consortium. Three authors independently extracted the data. They extracted the authors’ name, publication year, study design, inclusion criteria, participant characteristics, the sample size of the intervention and control groups, methods of neuroplasticity testing, as well as all means and standard deviations of primary and secondary neuroplasticity outcomes from each study. Data reported on copers were considered as part of the control group. The quality assessment tool for observational and cross-sectional studies was used for the risk of bias assessment. This study is registered on PROSPERO, number CRD42021281956. Results Twenty articles were included, of which only one investigated individuals who experienced a lateral ankle sprain. In all studies combined, 356 patients with chronic ankle instability, 10 who experienced a lateral ankle sprain and 46 copers were included. White matter microstructure changes in the cerebellum have been related to lateral ankle sprains. Fifteen studies reported functional brain adaptations in patients with chronic ankle instability, and five articles found structural brain outcomes. Alterations in the sensorimotor network (precentral gyrus and supplementary motor area, postcentral gyrus and middle frontal gyrus) and dorsal anterior cingulate cortex were mainly found in patients with chronic ankle instability. Discussion The included studies demonstrated structural and functional brain adaptations related to lateral ankle sprains and chronic ankle instability compared to healthy individuals or copers. These adaptations correlate with clinical outcomes (e.g. patients’ self-reported function and different clinical assessments) and might contribute to the persisting dysfunctions, increased re-injury risk and long-term sequelae seen in these patients. Thus, rehabilitation programmes should integrate sensorimotor and motor control strategies to cope with neuroplasticity related to ligamentous ankle injuries.
Neural Correlates of Verbal Working Memory: An fMRI Meta-Analysis
Verbal Working memory (vWM) capacity measures the ability to maintain and manipulate verbal information for a short period of time. The specific neural correlates of this construct are still a matter of debate. The aim of this study was to conduct a coordinate-based meta-analysis of 42 fMRI studies on visual vWM in healthy subjects ( = 795, males = 459, females = 325, unknown = 11; age range: 18-75). The studies were obtained after an exhaustive literature search on PubMed, Scopus, Web of Science, and Brainmap database. We analyzed regional activation differences during fMRI tasks with the anisotropic effect-size version of seed-based d mapping software (ES-SDM). The results were further validated by performing jackknife sensitivity analyses and heterogeneity analyses. We investigated the effect of numerous relevant influencing factors by fitting corresponding linear regression models. We isolated consistent activation in a network containing fronto-parietal areas, right cerebellum, and basal ganglia structures. Regarding lateralization, the results pointed toward a bilateral frontal activation, a left-lateralization of parietal regions and a right-lateralization of the cerebellum, indicating that the left-hemisphere concept of vWM should be reconsidered. We also isolated activation in regions important for response inhibition, emphasizing the role of attentional control in vWM. Moreover, we found a significant influence of mean reaction time, load, and age on activation associated with vWM. Activation in left medial frontal gyrus, left precentral gyrus, and left precentral gyrus turned out to be positively associated with mean reaction time whereas load was associated with activation across the PFC, fusiform gyrus, parietal cortex, and parts of the cerebellum. In the latter case activation was mainly detectable in both hemispheres whereas the influence of age became manifest predominantly in the left hemisphere. This led us to conclude that future vWM studies should take these factors into consideration.
A motor association area in the depths of the central sulcus
Cells in the precentral gyrus directly send signals to the periphery to generate movement and are principally organized as a topological map of the body. We find that movement-induced electrophysiological responses from depth electrodes extend this map three-dimensionally throughout the gyrus. Unexpectedly, this organization is interrupted by a previously undescribed motor association area in the depths of the midlateral aspect of the central sulcus. This ‘Rolandic motor association’ (RMA) area is active during movements of different body parts from both sides of the body and may be important for coordinating complex behaviors. Using depth electrodes in human patients, scientists at the Mayo Clinic found that the map of the body in motor cortex extends deep into the central sulcus. Unexpectedly, the nonsomatotopic ‘Rolandic motor association’ (RMA) area interrupts this organization.
Mapping gray and white matter volume abnormalities in early-onset psychosis: an ENIGMA multicenter voxel-based morphometry study
Introduction Regional gray matter (GM) alterations have been reported in early-onset psychosis (EOP, onset before age 18), but previous studies have yielded conflicting results, likely due to small sample sizes and the different brain regions examined. In this study, we conducted a whole brain voxel-based morphometry (VBM) analysis in a large sample of individuals with EOP, using the newly developed ENIGMA-VBM tool. Methods 15 independent cohorts from the ENIGMA-EOP working group participated in the study. The overall sample comprised T1-weighted MRI data from 482 individuals with EOP and 469 healthy controls. Each site performed the VBM analysis locally using the standardized ENIGMA-VBM tool. Statistical parametric T-maps were generated from each cohort and meta-analyzed to reveal voxel-wise differences between EOP and healthy controls as well as the individual-based association between GM volume and age of onset, chlorpromazine (CPZ) equivalent dose, and other clinical variables. Results Compared with healthy controls, individuals with EOP showed widespread lower GM volume encompassing most of the cortex, with the most marked effect in the left median cingulate (Hedges’ g  = 0.55, p  = 0.001 corrected), as well as small clusters of lower white matter (WM), whereas no regional GM or WM volumes were higher in EOP. Lower GM volume in the cerebellum, thalamus and left inferior parietal gyrus was associated with older age of onset. Deficits in GM in the left inferior frontal gyrus, right insula, right precentral gyrus and right superior frontal gyrus were also associated with higher CPZ equivalent doses. Conclusion EOP is associated with widespread reductions in cortical GM volume, while WM is affected to a smaller extent. GM volume alterations are associated with age of onset and CPZ equivalent dose but these effects are small compared to case-control differences. Mapping anatomical abnormalities in EOP may lead to a better understanding of the role of psychosis in brain development during childhood and adolescence.
Decreased cortical gyrification in patients with bipolar disorder
BackgroundAn aberrant neural connectivity has been known to be associated with bipolar disorder (BD). Local gyrification may reflect the early neural development of cortical connectivity and has been studied as a possible endophenotype of psychiatric disorders. This study aimed to investigate differences in the local gyrification index (LGI) in each cortical region between patients with BD and healthy controls (HCs).MethodsLGI values, as measured using FreeSurfer software, were compared between 61 patients with BD and 183 HCs. The values were also compared between patients with BD type I and type II as a sub-group analysis. Furthermore, we evaluated whether there was a correlation between LGI values and illness duration or depressive symptom severity in patients with BD.ResultsPatients with BD showed significant hypogyria in various cortical regions, including the left inferior frontal gyrus (pars opercularis), precentral gyrus, postcentral gyrus, superior temporal cortex, insula, right entorhinal cortex, and both transverse temporal cortices, compared to HCs after the Bonferroni correction (p < 0.05/66, 0.000758). LGI was not associated with clinical factors such as illness duration, depressive symptom severity, and lithium treatment. No significant differences in cortical gyrification according to the BD subtype were found.ConclusionsBD appears to be characterized by a significant regionally localized hypogyria, in various cortical areas. This abnormality may be a structural and developmental endophenotype marking the risk for BD, and it might help to clarify the etiology of BD.