title: Burst firing synchronizes prefrontal and anterior cingulate cortex during attentional control.
abstract: BACKGROUND
  It is widely held that single cells in anterior cingulate and lateral prefrontal cortex (ACC/PFC) coordinate their activity during attentional processes, although cellular activity that may underlie such coordination across ACC/PFC has not been identified. We thus recorded cells in five ACC/PFC subfields of macaques engaged in a selective attention task, characterized those spiking events that indexed attention, and identified how spiking of distinct cell populations synchronized between brain areas.
  
  
  RESULTS
  We found that cells in ACC/PFC increased the firing of brief 200 Hz spike bursts when subjects shifted attention and engaged in selective visual processing. In contrast to nonburst spikes, burst spikes synchronized over large distances to local field potentials at narrow beta (12-20 Hz) and at gamma (50-75 Hz) frequencies. Long-range burst synchronization was anatomically specific, functionally connecting those subfields in area 24 (ACC) and area 46 (PFC) that are key players of attentional control. By splitting cells into putative excitatory (pE) and inhibitory (pI) cells by their broad and narrow spikes, we identified that bursts of pI cells preceded and that bursts of pE cells followed in time periods of maximal beta coherent network activity. In contrast, gamma bursts were transient impulses with equal timing across cell classes.
  
  
  CONCLUSIONS
  These findings suggest that processes underlying burst firing and burst synchronization are candidate mechanisms to coordinate attention information across brain areas. We speculate that distinct burst-firing motifs realize beta and gamma synchrony to trigger versus maintain functional network states during goal-directed behavior.
authors.affiliation: Department of Biology, Centre for Vision Research, York University, 4700 Keele Street, Toronto, ON M6J 1P3, Canada; Department of Physiology and Pharmacology, Centre for Functional and Metabolic Mapping, University of Western Ontario, 1151 Richmond Street North, London, ON N6A 5B7, Canada. Electronic address: thiwom@yorku.ca.
authors.forename: Thilo
authors.initials: T
authors.lastname: Womelsdorf
authors.affiliation: Department of Biology, Centre for Vision Research, York University, 4700 Keele Street, Toronto, ON M6J 1P3, Canada.
authors.forename: Salva
authors.initials: S
authors.lastname: Ardid
authors.affiliation: Department of Physiology and Pharmacology, Centre for Functional and Metabolic Mapping, University of Western Ontario, 1151 Richmond Street North, London, ON N6A 5B7, Canada.
authors.forename: Stefan
authors.initials: S
authors.lastname: Everling
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Research Institute, Toronto, ON M5T 2S8, Canada; Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON M5T 1P5, Canada.
authors.forename: Taufik A
authors.initials: TA
authors.lastname: Valiante
mesh_terms: D000200:Action Potentials; D000818:Animals; D001288:Attention; D001931:Brain Mapping; D006179:Gyrus Cinguli / Q000502:physiology*; D008251:Macaca / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology