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The Claustrum's Proposed Role in Consciousness Is Supported by the Effect and Target Localization of Salvia Divinorum


The Claustrum's Proposed Role in Consciousness Is Supported by the Effect and Target Localization of Salvia Divinorum

Klaus M Stiefel et al. Front Integr Neurosci.


THIS ARTICLE BRINGS TOGETHER THREE FINDINGS AND IDEAS RELEVANT FOR THE UNDERSTANDING OF HUMAN CONSCIOUSNESS: (I) Crick's and Koch's theory that the claustrum is a "conductor of consciousness" crucial for subjective conscious experience. (II) Subjective reports of the consciousness-altering effects the plant Salvia divinorum, whose primary active ingredient is salvinorin A, a κ-opioid receptor agonist. (III) The high density of κ-opioid receptors in the claustrum. Fact III suggests that the consciousness-altering effects of S. divinorum/salvinorin A (II) are due to a κ-opioid receptor mediated inhibition of primarily the claustrum and, additionally, the deep layers of the cortex, mainly in prefrontal areas. Consistent with Crick and Koch's theory that the claustrum plays a key role in consciousness (I), the subjective effects of S. divinorum indicate that salvia disrupts certain facets of consciousness much more than the largely serotonergic hallucinogen lysergic acid diethylamide (LSD). Based on this data and on the relevant literature, we suggest that the claustrum does indeed serve as a conductor for certain aspects of higher-order integration of brain activity, while integration of auditory and visual signals relies more on coordination by other areas including parietal cortex and the pulvinar.

Keywords: Salvia divinorum; claustrum; consciousness; salvinorin A; κ-opioid receptor.


Connectivity and κ-opioid receptor density of the claustrum in the human brain. (A) The claustrum is strongly connected to diverse cortical areas, with the sections of the claustrum receiving cortical inputs overlapping. This anatomical connection pattern, amongst other things, leads Crick and Koch to propose that the claustrum acts as a director of consciousness. The connectivity was established by injecting horseradish peroxidase into the cortex, and subsequently tracing the marked cells in the claustrum. Figure from Crick and Koch (2005), as modified from the original study (Phelps and LeDoux, 2005). (B) In situ hybridization signal of κ-opioid receptor mRNA. The darker the staining of the tissue, the higher the density of κ-opioid receptor mRNA, and subsequently of κ-opioid receptors. Cl: claustrum. Scale bar = 5 mm. Figure from Peckys and Landwehrmeyer (1999).
Comparison of the average rating (top row) and number of trip questions that received ratings (bottom row) for S. divinorum and LSD trip reports.> See trip report analysis deposited at for associated statistics. Error bars are 95% confidence intervals. For the counts, the confidence intervals were calculated with Agresti and Caffo’s (2000) add-4 method and for the mean ratings, they were bootstrapped.

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    1. Addy P. H. (2012). Acute and post-acute behavioral and psychological effects of salvinorin A in humans. Psychopharmacology 220 195–20410.1007/s00213-011-2470-6 - DOI - PubMed
    1. Agresti A., Caffo B. (2000). Simple and effective confidence intervals for proportions and difference of proportions result from adding two successes and two failures. Am. Stat. 54 280–288
    1. Ansonoff M. A., Zhang J., Czyzyk T., Rothman R. B., Stewart J., Xu H., et al. (2006). Antinociceptive and hypothermic effects of Salvinorin A are abolished in a novel strain of kappa-opioid receptor-1 knockout mice. J. Pharmacol. Exp. Ther. 318 641–64810.1124/jpet.106.101998 - DOI - PubMed
    1. Arend I., Rafal R., Ward R. (2008). Spatial and temporal deficits are regionally dissociable in patients with pulvinar lesions. Brain 131 2140–215210.1093/brain/awn135 - DOI - PubMed
    1. Arthur J. D. (2008). Peopled Darkness: Perceptual Transformation through Salvia divinorum. Bloomington: iUniverse

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