An integrative theory of locus coeruleus-norepinephrine function: adaptive gain and optimal performance.
Historically, the locus coeruleus-norepinephrine (LC-NE) system has been implicated in arousal, but recent findings suggest that this system plays a more complex and specific role in the control of behavior than investigators previously thought. We review neurophysiological and modeling studies in monkey that support a new theory of LC-NE function. LC neurons exhibit two modes of activity, phasic and tonic. Phasic LC activation is driven by the outcome of task-related decision processes and is proposed to facilitate ensuing behaviors and to help optimize task performance (exploitation). When utility in the task wanes, LC neurons exhibit a tonic activity mode, associated with disengagement from the current task and a search for alternative behaviors (exploration). Monkey LC receives prominent, direct inputs from the anterior cingulate (ACC) and orbitofrontal cortices (OFC), both of which are thought to monitor task-related utility. We propose that these frontal areas produce the above patterns of LC activity to optimize utility on both short and long timescales.
Aston-Jones
Gary
G
Laboratory of Neuromodulation and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA. gaj@mail.med.upenn.edu
Cohen
Jonathan D
JD
D000200:Action Potentials / Q000502:physiology; D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology; D006801:Humans; D008125:Locus Coeruleus / Q000502:physiology*; D016571:Neural Networks, Computer; D009638:Norepinephrine / Q000502:physiology*; D018511:Systems Integration; D013997:Time Factors
D009638:Norepinephrine