Cytoarchitecture, probability maps, and functions of the human supplementary and pre-supplementary motor areas

Abstract

The dorsal mesial frontal cortex contains the supplementary motor area (SMA) and the pre-supplementary motor area (pre-SMA), which play an important role in action and cognition. Evidence from cytoarchitectonic, stimulation, and functional studies suggests structural and functional divergence between the two subregions. However, a microstructural map of these areas obtained in a representative sample of brains in a stereotaxic reference space is still lacking. In the present study we show that the dorsal mesial frontal motor cortex comprises two microstructurally different brain regions: area SMA and area pre-SMA. Area-specific cytoarchitectonic patterns were studied in serial histological sections stained for cell bodies of ten human postmortem brains. Borders of the two cortical areas were identified using image analysis and statistical features. The 3D reconstructed areas were transferred to a common reference space, and probabilistic maps were calculated by superimposing the individual maps. A coordinate-based meta-analysis of functional imaging data was subsequently performed using the two probabilistic maps as microstructurally defined seed regions. It revealed that areas SMA and pre-SMA were strongly co-activated with areas in precentral, supramarginal and superior frontal gyri, Rolandic operculum, thalamus, putamen and cerebellum. Both areas were related to motor functions, but area pre-SMA was involved in more complex processes such as learning, cognitive processes and perception. The here described subsequent analyses led to converging evidence supporting the microstructural, and functional segregation of areas SMA and pre-SMA, and maps will be made available to the scientific community to further elucidate the microstructural substrates of motor and cognitive control.Electronic supplementary materialThe online version of this article (10.1007/s00429-018-1738-6) contains supplementary material, which is available to authorized users.

Cytoarchitectonic Characterization and Functional Decoding of Four New Areas in the Human Lateral Orbitofrontal Cortex

“…The present study provides a comprehensive cytoarchitectonic analysis of the human lateral OFC using a computerized approach to detect cytoarchitectonic borders between adjacent areas based on image analysis and statistical criteria (Schleicher et al, 1998(Schleicher et al, , 1999(Schleicher et al, , 2005, and provides cytoarchitectonic probabilistic maps in 3D reference space (Amunts and Zilles, 2015). The maps have been created based on the same methods as used for previous mapping studies of our group [most recent include, e.g., the parietal cortex (Richter et al, 2019), the motor cortex (Ruan et al, 2018), and the fusiform gyrus (Lorenz et al, 2017)], and allow to integrate them into a coherent atlas framework of the human brain. Meta-analytic connectivity modeling (MACM) was conducted to assess all task-based functional connectivities between the lateral OFC areas and their respective co-activated FIGURE 1 | Area 47 in the lateral orbitofrontal cortex (lateral OFC) in the human brain according to previous cytoarchitectonical analyses (Brodmann, 1909;von Economo and Koskinas, 1925;Von Economo, 1929;Öngür et al, 2003).…”

Individual Prediction of Psychotherapy Outcome in Posttraumatic Stress Disorder using Neuroimaging Data

“…This brain area is closely linked to the SMA and both areas are involved in motor execution and imagination. However, the pre-SMA can also be distinguished from the SMA, and is more involved in higher cognitive processes such as working memory, language and task switching (32, 33). Furthermore, the pre-SMA has been implicated to be involved in the process of response inhibition which has been previously related to PTSD development and treatment-response in PTSD (see (34) for a review).…”

A Comprehensive sLORETA Study on the Contribution of Cortical Somatomotor Regions to Motor Imagery

“…SMA activity was also observed during motor imagery tasks in the same study. The SMA and pSMA regions have a relationship with motor function planning, processing, and execution [23,24].…”