In this study, forelimb organizations and output properties of the supplementary motor area (SMA) and the dorsal cingulate motor area (CMAd) were assessed and compared with primary motor cortex (M1). Stimulus-triggered averages of electromyographic activity from 24 muscles of the forelimb were computed from layer V sites of 2 rhesus monkeys performing a reach-to-grasp task. No clear segregation of the forelimb representation of proximal and distal muscles was found in SMA. In CMAd, sites producing poststimulus effects in proximal muscles tended to be located caudal to distal muscle sites, although the number of effects was limited. For both SMA and CMAd, facilitation effects were more prevalent in distal than in proximal muscles. At an intensity of 60 microA, the mean latencies of M1 facilitation effects were 8 and 12.1 ms shorter and the magnitudes approximately 10 times greater than those from SMA and CMAd. Our results show that corticospinal neurons in SMA and CMAd provide relatively weak input to spinal motoneurons compared with the robust effects from M1. However, a small number of facilitation effects from SMA and CMAd had latencies as short as the shortest ones from M1 suggesting a minimum linkage to motoneurons as direct as that from M1.
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http://dx.doi.org/10.1093/cercor/bhp136 | DOI Listing |
Front Aging Neurosci
May 2022
Department of Nursing, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Objective: To investigate the effects of sport stacking on the overall cognition and brain function in patients with mild Alzheimer's disease (AD) and mild cognitive impairment (MCI).
Methods: A single-blind randomized controlled design was performed using sport stacking for 30 min, 5 days/week for 12 weeks. Forty-eight subjects with mild AD or MCI were randomly divided into the sport stacking group (T-mAD = 12, T-MCI = 12) and the active control group (C-mAD = 11, C-MCI = 13).
Cereb Cortex
March 2010
Department of Molecular & Integrative Physiology, University of Kansas Medical Center (KUMC), Kansas City, KS 66160, USA.
In this study, forelimb organizations and output properties of the supplementary motor area (SMA) and the dorsal cingulate motor area (CMAd) were assessed and compared with primary motor cortex (M1). Stimulus-triggered averages of electromyographic activity from 24 muscles of the forelimb were computed from layer V sites of 2 rhesus monkeys performing a reach-to-grasp task. No clear segregation of the forelimb representation of proximal and distal muscles was found in SMA.
View Article and Find Full Text PDFJ Neurophysiol
November 2002
Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
The cingulate motor areas are a recently discovered group of discrete cortical regions located in the cingulate sulcus with direct connections to the primary motor cortex and spinal cord. Although much is known about their anatomical relationship with other motor areas, relatively little is known about their functional neurophysiology. We investigated neural mechanisms of motor processing in the dorsal and ventral cingulate motor areas (CMAd and CMAv) during two-dimensional visually guided arm movements.
View Article and Find Full Text PDFBrain Res Brain Res Rev
October 2001
Institute of Neuroradiology, University Hospital of Zurich, Frauenklinikstrasse 10, CH 8091, Zurich, Switzerland.
The human cortex reportedly contains at least five nonprimary motor areas: in the frontolateral convexity, the dorsal and ventral premotor cortex (PMd and PMv), and in the frontomesial wall, the presupplementary and supplementary motor areas (pre-SMA and SMA), and the rostral, dorsal and ventral cingulate areas (CMAr, CMAd, and CMAv). Activation of these regions in neuroimaging studies has been generally associated either with the performance of complex motor tasks or with reorganization occurring with motor recovery in the presence of pathology. Recent evidence from neuroimaging studies suggests that the same areas are activated with well controlled simple movements in healthy subjects providing support to the observation that their contribution may be more quantitative rather than exclusively specific to a certain aspect of motor behaviour.
View Article and Find Full Text PDFNovartis Found Symp
February 1999
Research Service, Veterans Administration Medical Center, Syracuse, NY, USA.
The primary motor cortex (M1) receives input from four premotor areas on the medial wall of the hemisphere: the supplementary motor area (SMA) and three cingulate motor areas located on the banks of the cingulate sulcus (CMAr, CMAd and CMAv). All four premotor areas have maps of the body containing distinct proximal and distal representations of the arm. Surprisingly, the size of the distal representation is comparable to or larger than the size of the proximal representation in each area.
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