Format

Send to

Choose Destination
Curr Biol. 2018 Jul 9;28(13):2145-2152.e5. doi: 10.1016/j.cub.2018.05.025. Epub 2018 Jun 21.

Differential Role of Prefrontal and Parietal Cortices in Controlling Level of Consciousness.

Author information

1
Department of Anesthesiology, University of Michigan, 7433 Medical Science Building 1, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5615, USA; Center for Consciousness Science, University of Michigan, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan, 4137 Undergraduate Science Building, 204 Washtenaw Avenue, Ann Arbor, MI 48109-2215, USA.
2
Center for Consciousness Science, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, 7744 Medical Science Building II, 1137 East Catherine Street, Ann Arbor, MI 48109-5622, USA.
3
Department of Anesthesiology, University of Michigan, 7433 Medical Science Building 1, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5615, USA.
4
Department of Anesthesiology, University of Michigan, 7433 Medical Science Building 1, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5615, USA; Center for Consciousness Science, University of Michigan, Ann Arbor, MI 48109, USA.
5
Department of Anesthesiology, University of Michigan, 7433 Medical Science Building 1, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5615, USA; Center for Consciousness Science, University of Michigan, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan, 4137 Undergraduate Science Building, 204 Washtenaw Avenue, Ann Arbor, MI 48109-2215, USA. Electronic address: gmashour@umich.edu.

Abstract

Consciousness is determined both by level (e.g., being awake versus being anesthetized) and content (i.e., the qualitative aspects of experience). Subcortical areas are known to play a causal role in regulating the level of consciousness [1-9], but the role of the cortex is less well understood. Clinical and correlative data have been used both to support and refute a role for prefrontal and posterior cortices in the level of consciousness [10-22]. The prefrontal cortex has extensive reciprocal connections to wake-promoting centers in the brainstem and diencephalon [23, 24], and hence is in a unique position to modulate level of consciousness. Furthermore, a recent study suggested that the prefrontal cortex might be important in regulating level of consciousness [25] but causal evidence, and a comparison with more posterior cortical sites, is lacking. Therefore, to test the hypothesis that prefrontal cortex plays a role in regulating level of consciousness, we attempted to reverse sevoflurane anesthesia by cholinergic or noradrenergic stimulation of the prefrontal prelimbic cortex and two areas of parietal cortex in rat. General anesthesia was defined by loss of the righting reflex, a widely used surrogate measure in rodents. We demonstrate that cholinergic stimulation of prefrontal cortex, but not parietal cortex, restored wake-like behavior, despite continuous exposure to clinically relevant concentrations of sevoflurane anesthesia. Noradrenergic stimulation of the prefrontal and parietal areas resulted in electroencephalographic activation but failed to produce any signs of wake-like behavior. We conclude that cholinergic mechanisms in prefrontal cortex can regulate the level of consciousness.

KEYWORDS:

acetylcholine; carbachol; consciousness; electroencephalogram; microdialysis; noradrenaline; parietal cortex; prefrontal cortex; rat; sevoflurane anesthesia

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center