Cortical and Subcortical Connectivity Changes during Decreasing Levels of Consciousness in Humans: A Functional Magnetic Resonance Imaging Study using Propofol

Mhuircheartaigh, Róisín Ní; Rosenorn-Lanng, Debbie; Wise, Richard G.; Jbabdi, Saâd; Rogers, Richard; Tracey, Irene

doi:10.1523/jneurosci.5516-09.2010

Cited by 199 publications

(178 citation statements)

References 60 publications

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“…Correlations between PMdr and the attention and control networks ranged in value from 0.75 to −0.3. These impulsivity-related differences are quite large in comparison with changes in functional connectivity achieved by varying task performance, sleep state, and even anesthesia (25)(26)(27)(28). Hence, it is unlikely that the presently observed functional connectivity differences are attributable to ongoing cognition.…”

Section: Resultsmentioning

confidence: 98%

Premotor functional connectivity predicts impulsivity in juvenile offenders

Shannon

Raichle

Snyder

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

123

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Teenagers are often impulsive. In some cases this is a phase of normal development; in other cases impulsivity contributes to criminal behavior. Using functional magnetic resonance imaging, we examined resting-state functional connectivity among brain systems and behavioral measures of impulsivity in 107 juveniles incarcerated in a high-security facility. In less-impulsive juveniles and normal controls, motor planning regions were correlated with brain networks associated with spatial attention and executive control. In more-impulsive juveniles, these same regions correlated with the default-mode network, a constellation of brain areas associated with spontaneous, unconstrained, self-referential cognition. The strength of these brain-behavior relationships was sufficient to predict impulsivity scores at the individual level. Our data suggest that increased functional connectivity of motor-planning regions with networks subserving unconstrained, self-referential cognition, rather than those subserving executive control, heightens the predisposition to impulsive behavior in juvenile offenders. To further explore the relationship between impulsivity and neural development, we studied functional connectivity in the same motorplanning regions in 95 typically developing individuals across a wide age span. The change in functional connectivity with age mirrored that of impulsivity: younger subjects tended to exhibit functional connectivity similar to the more-impulsive incarcerated juveniles, whereas older subjects exhibited a less-impulsive pattern. This observation suggests that impulsivity in the offender population is a consequence of a delay in typical development, rather than a distinct abnormality.self-control | psychopathy | functional MRI S elf-control is an important cognitive ability that develops with age. Individual variability in self-control has been linked to a wide variety of life outcomes, ranging from educational and economic achievement to likelihood of incarceration (1, 2).Clinical disorders of self-control can take several forms, including attention-deficit/hyperactivity disorder (ADHD), antisocial personality disorder, psychopathy, and conduct disorder. Each has received attention from neuroscientists, often focused on structural MRI or functional activation experiments (3, 4), although several studies also examine resting functional connectivity (5). Of particular relevance to the present results are theories that emphasize the role of attentional processes in these disorders. For example, Newman identified differences in attentional abilities in juveniles and adults with psychopathic traits, suggesting that an inability to properly focus on relevant stimuli contributed to their disorder (6, 7).The etiology of these disorders remains cloudy. We know that young children lack self-control but gradually acquire it over the course of development (8). At what point does pathological impulsivity deviate from typical developmental trajectories? Clues may be found by comparing functional brain activity ...

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Section: Resultsmentioning

confidence: 98%

Premotor functional connectivity predicts impulsivity in juvenile offenders

Shannon

Raichle

Snyder

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

123

View full text Add to dashboard Cite

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“…Suppressed frontoparietal and thalamic activity appear to be a common finding in most anesthesia studies (Kaisti et al, 2002;Baars et al, 2003;Bonhomme et al, 2008;Mhuircheartaigh et al, 2010;Stamatakis et al, 2010;Schrouff et al, 2011;Tu et al, 2011). These changes have generally been interpreted directly as neural correlates for LOC.…”

Section: Discussionmentioning

confidence: 97%

“…A number of studies have now examined the connectivity effects associated with changing levels of consciousness (Imas et al, 2005;Massimini et al, 2005;Boveroux et al, 2010;Mhuircheartaigh et al, 2010;Stamatakis et al, 2010;Boly, 2011;Boly et al, 2011;Schrouff et al, 2011). It has been hypothesized that decreased frontal to parietal feedback is a likely correlate for the diminished consciousness associated with sleep (Massimini et al, 2005), brain injury , and anesthesia (Imas et al, 2005;Alkire et al, 2008;Ku et al, 2011).…”

Section: Discussionmentioning

confidence: 99%

Returning from Oblivion: Imaging the Neural Core of Consciousness

Långsjö

Alkire²,

Kaskinoro³

et al. 2012

J. Neurosci.

190

147

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One of the greatest challenges of modern neuroscience is to discover the neural mechanisms of consciousness and to explain how they produce the conscious state. We sought the underlying neural substrate of human consciousness by manipulating the level of consciousness in volunteers with anesthetic agents and visualizing the resultant changes in brain activity using regional cerebral blood flow imaging with positron emission tomography. Study design and methodology were chosen to dissociate the state-related changes in consciousness from the effects of the anesthetic drugs. We found the emergence of consciousness, as assessed with a motor response to a spoken command, to be associated with the activation of a core network involving subcortical and limbic regions that become functionally coupled with parts of frontal and inferior parietal cortices upon awakening from unconsciousness. The neural core of consciousness thus involves forebrain arousal acting to link motor intentions originating in posterior sensory integration regions with motor action control arising in more anterior brain regions. These findings reveal the clearest picture yet of the minimal neural correlates required for a conscious state to emerge.

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“…While early fMRI studies of BOLD signal fluctuations across levels of consciousness reported persistent intrinsic activity and relatively preserved spatial organization during light sleep and sedation (Greicius et al, 2008;Horovitz et al, 2008;LarsonPrior et al, 2009), recent studies point to a state-dependent modulation: during propofol-anesthesia, a linear association between functional connectivity of frontoparietal networks and levels of consciousness (Boveroux et al, 2010), a reorganization of key nodes of the default mode network (Stamatakis et al, 2010), and decreased subcortical-cortical connectivity have been reported (Mhuircheartaigh et al, 2010). State-dependent changes in functional connectivity have also been observed during deep NREM sleep (Horovitz et al, 2009;Sämann et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Reconfiguration of Large-Scale Brain Functional Networks during Propofol-Induced Loss of Consciousness

et al. 2012

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Applying graph theoretical analysis of spontaneous BOLD fluctuations in functional magnetic resonance imaging (fMRI), we investigated whole-brain functional connectivity of 11 healthy volunteers during wakefulness and propofol-induced loss of consciousness (PI-LOC). After extraction of regional fMRI time series from 110 cortical and subcortical regions, we applied a maximum overlap discrete wavelet transformation and investigated changes in the brain's intrinsic spatiotemporal organization. During PI-LOC, we observed a breakdown of subcortico-cortical and corticocortical connectivity. Decrease of connectivity was pronounced in thalamocortical connections, whereas no changes were found for connectivity within primary sensory cortices. Graph theoretical analyses revealed significant changes in the degree distribution and local organization metrics of brain functional networks during PI-LOC: compared with a random network, normalized clustering was significantly increased, as was small-worldness. Furthermore we observed a profound decline in long-range connections and a reduction in whole-brain spatiotemporal integration, supporting a topological reconfiguration during PI-LOC. Our findings shed light on the functional significance of intrinsic brain activity as measured by spontaneous BOLD signal fluctuations and help to understand propofol-induced loss of consciousness.

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Cortical and Subcortical Connectivity Changes during Decreasing Levels of Consciousness in Humans: A Functional Magnetic Resonance Imaging Study using Propofol

Cited by 199 publications

References 60 publications

Premotor functional connectivity predicts impulsivity in juvenile offenders

Premotor functional connectivity predicts impulsivity in juvenile offenders

Returning from Oblivion: Imaging the Neural Core of Consciousness

Spatiotemporal Reconfiguration of Large-Scale Brain Functional Networks during Propofol-Induced Loss of Consciousness

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