Medial frontal cortex (MFC) is crucial when actions have to be inhibited, reprogrammed, or selected under conflict, but the precise mechanism by which it operates is unclear. Importantly, how and when the MFC influences the primary motor cortex (M1) during action selection is unknown. Using paired-pulse transcranial magnetic stimulation, we investigated functional connectivity between the presupplementary motor area (pre-SMA) part of MFC and M1. We found that functional connectivity increased in a manner dependent on cognitive context: pre-SMA facilitated the motor evoked-potential elicited by M1 stimulation only during action reprogramming, but not when otherwise identical actions were made in the absence of conflict. The effect was anatomically specific to pre-SMA; it was not seen when adjacent brain regions were stimulated. We discuss implications for the anatomical pathways mediating the observed effects.
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http://dx.doi.org/10.1523/JNEUROSCI.1396-09.2009 | DOI Listing |
Brain Imaging Behav
January 2025
Department of Medical Imaging, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
Insomnia disorder is a significant global health concern. This research aimed to explore the pathogenesis of insomnia disorder using static and dynamic degree centrality methods at the voxel level. A total of 29 patients diagnosed with insomnia disorder and 28 healthy controls were ultimately included to examine differences in degree centrality between the two groups.
View Article and Find Full Text PDFAlzheimers Dement
January 2025
Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Sanya, China.
Introduction: Alzheimer's disease (AD) is the most common neurodegenerative disease, characterized by damage to cortical circuits. However, the mechanisms underlying AD-associated changes in long-range circuits remain poorly understood.
Methods: In this study, we used viral tracing and fluorescence micro-optical sectioning tomography (fMOST) imaging to investigate whole-brain changes in the input circuit of the frontal cortex of 5×FAD mice.
Alzheimers Dement
January 2025
Guangdong Provincial Key Laboratory of Brain Function and Disease, Center for Brain and Mental Well-Being, Department of Psychology, Sun Yat-sen University, Guangzhou, China.
Introduction: Visual short-term memory (VSTM) is a critical indicator of Alzheimer's disease (AD), but whether its neural substrates could adapt to early disease progression and contribute to cognitive resilience in amnestic mild cognitive impairment (aMCI) has been unclear.
Methods: Fifty-five aMCI patients and 68 normal controls (NC) performed a change-detection task and underwent multimodal neuroimaging scanning.
Results: Among the atrophic brain regions in aMCI, VSTM performance correlated with the volume of the right prefrontal cortex (PFC) but not the medial temporal lobe (MTL), and this correlation was mainly present in patients with greater MTL atrophy.
Front Child Adolesc Psychiatry
November 2024
Department of Psychology, Palo Alto University, Palo Alto, CA, United States.
Introduction: Autism Spectrum Disorder (ASD) is characterized by deficits in social cognition, self-referential processing, and restricted repetitive behaviors. Despite the established clinical symptoms and neurofunctional alterations in ASD, definitive biomarkers for ASD features during neurodevelopment remain unknown. In this study, we aimed to explore if activation in brain regions of the default mode network (DMN), specifically the medial prefrontal cortex (MPC), posterior cingulate cortex (PCC), superior temporal sulcus (STS), inferior frontal gyrus (IFG), angular gyrus (AG), and the temporoparietal junction (TPJ), during resting-state functional magnetic resonance imaging (rs-fMRI) is associated with possible phenotypic features of autism (PPFA) in a large, diverse youth cohort.
View Article and Find Full Text PDFPsychiatry Clin Neurosci
January 2025
Department of Radiology, and Functional and Molecular Imaging key Laboratory of Sichuan Province, West China Hospital of Sichuan University, Chengdu, China.
Aim: As a central component of schizophrenia psychopathology, negative symptoms result in detrimental effects on long-term functional prognosis. However, the neurobiological mechanism underlying negative symptoms remains poorly understood, which limits the development of novel treatment interventions. This study aimed to identify the specific neural fingerprints of negative symptoms in schizophrenia.
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