title: What do phasic cholinergic signals do?
abstract: In addition to the neuromodulatory role of cholinergic systems, brief, temporally discrete cholinergic release events, or "transients", have been associated with the detection of cues in attention tasks. Here we review four main findings about cholinergic transients during cognitive processing. Cholinergic transients are: (1) associated with the detection of a cue and influenced by cognitive state; (2) not dependent on reward outcome, although the timing of the transient peak co-varies with the temporal relationship between detection and reward delivery; (3) correlated with the mobilization of the cue-evoked response; (4) causal mediators of shifts from monitoring to cue detection. We next discuss some of the key questions concerning the timing and occurrence of transients within the framework of available evidence including: (1) Why does the shift from monitoring to cue detection require a transient? (2) What determines whether a cholinergic transient will be generated? (3) How can cognitive state influence transient occurrence? (4) Why do cholinergic transients peak at around the time of reward delivery? (5) Is there evidence of cholinergic transients in humans? We conclude by outlining future research studies necessary to more fully understand the role of cholinergic transients in mediating cue detection.
authors.affiliation: University of Michigan, Dept. of Psychology and Neuroscience Program, Ann Arbor, MI, United States. Electronic address: msarter@umich.edu.
authors.forename: Martin
authors.initials: M
authors.lastname: Sarter
authors.affiliation: University of Michigan, Dept. of Psychology and Neuroscience Program, Ann Arbor, MI, United States. Electronic address: clustig@umich.edu.
authors.forename: Cindy
authors.initials: C
authors.lastname: Lustig
authors.affiliation: Lawrence Berkeley National Laboratory, UC Berkeley, Berkeley, CA, United States.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Berry
authors.affiliation: Boston University, Dept. of Biomedical Engineering, Boston, MA, United States.
authors.forename: Howard
authors.initials: H
authors.lastname: Gritton
authors.affiliation: Boston University, Dept. of Biomedical Engineering, Boston, MA, United States; Pfizer Neuroscience, Cambridge, MA, United States.
authors.forename: William M
authors.initials: WM
authors.lastname: Howe
authors.affiliation: Temple University, Dept. of Psychology and Neuroscience Program, Philadelphia, PA, United States.
authors.forename: Vinay
authors.initials: V
authors.lastname: Parikh
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001288:Attention / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D059329:Cholinergic Neurons / Q000378:metabolism*; D003071:Cognition / Q000502:physiology; D003463:Cues; D006801:Humans; D012201:Reward
chemical_list: D000109:Acetylcholine
keywords: Acetylcholine; Attention; Cognition; Cortex