BROADMANN AREAS

A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells.

Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely known and frequently cited cytoarchitectural organization of the human cortex.

Many of the areas Brodmann defined based solely on their neuronal organization have since been correlated closely to diverse cortical functions. For example, Brodmann areas 1, 2 and 3 are the primary somatosensory cortex; area 4 is the primary motor cortex; area 17 is the primary visual cortex; and areas 41 and 42 correspond closely to primary auditory cortex. Higher order functions of the association cortical areas are also consistently localized to the same Brodmann areas by neurophysiological, functional imaging, and other methods (e.g., the consistent localization of Broca's speech and language area to the left Brodmann areas 44 and 45). However, functional imaging can only identify the approximate localization of brain activations in terms of Brodmann areas since their actual boundaries in any individual brain requires its histological examination.

Now (July 2016), scientists have built an updated map of the brain that further refines the Brodmann areas. The new map reveals 97 previously unknown areas of the brain’s surface (the cortex), in addition to 83 areas that were described before.

Unlike Brodmann’s and other brain maps built using just one property (how the cells looked under a microscope, for example), the new atlas is made by combining several types of data that capture multiple properties of these brain areas: their anatomy, their function and the connections between them.

The data was gathered using multiple non-invasive brain imaging measures from 210 people in the NIH Human Connectome Project, and the accuracy of the resulting map was confirmed on another group of 210 people.

“The researchers combined measures of the thickness of the cortex and the amount of insulation around neuronal cables, with MRI scans of the resting brain and of the brain performing simple tasks, such as listening to a story.”......more Glial/astrocyte ignorance!!!!!