Harvard Ascending Arousal Network Atlas – Version 2.0

The ascending arousal network (AAN) is a subcortical neural network that is critical to consciousness. AAN neurons connect the brainstem to the thalamus, hypothalamus, basal forebrain and cortex, activating cortically-based awareness networks. The reticular core of the AAN was first described by Moruzzi and Magoun in 1949, who coined the classical term \"ascending reticular activating system\" (Electroencephalogr Clin Neurophysiol 1949;1:455-73). Here, we use the term AAN because many brainstem nuclei that contribute to arousal are located outside of the pontine and midbrain reticular core (e.g., locus coeruleus, parabrachial complex, etc.), and because we believe that the word \"network\" appropriately connotes the physiological mechanisms by which multiple modular circuits interrelate to enable the emergent property of arousal, and hence consciousness. To date, the majority of studies investigating AAN connectivity have utilized animal models. As a result, current knowledge about the stru..., ,