Harvard Ascending Arousal Network Atlas
The above figure shows an anterior (front) view in panel A and a posterior (back) view in panel B of brainstem nuclei that are critical to human consciousness. These nuclei were manually traced on an ultra-high resolution MRI of a human brainstem. The locations and borders of the nuclei on the MRI dataset were correlated with microscopic analysis of the same human brainstem after it was scanned. The neuroanatomic information from this human brainstem, along with neuroanatomic data from standard atlases of the human brainstem, formed the basis for the Harvard Ascending Arousal Network Atlas (www.martinos.org/resources/aan-atlas). Figure adapted from Edlow BL, Takahashi E, Wu O, Benner T, Dai G, Bu L, Grant PE, Greer DM, Greenberg SM, Kinney HC, Folkerth RD. Neuroanatomic connectivity of the human ascending arousal system critical to consciousness and its disorders. Journal of Neuropathology and Experimental Neurology. 2012;71:531-546.
The ascending arousal network (AAN) is a subcortical neural network that is critical to consciousness. To date, the majority of studies investigating AAN connectivity have utilized animal models. As a result, current knowledge about the connectivity of the human AAN is largely based upon extrapolations from animal data.
We created an AAN atlas to facilitate research into the structural and functional connectivity of the human AAN. The study of AAN "connectomics" has the potential to increase knowledge about arousal physiology in the human brain, as well as arousal pathology in neurological diseases, such as coma and other disorders of consciousness.
In addition, the study of AAN connectomics may advance knowledge about reciprocal connectivity between this subcortical arousal network and cortically based awareness networks, such as the default mode network.
More information about the Harvard Ascending Arousal Network Atlas can be found at https://www.martinos.org/resources/aan-atlas. In addition, regions of interest for AAN nuclei in MNI152 space can be downloaded at this site.