Table 2.
Summary of the known effects of anesthetic agents on brain function.
| Functional connectivity | Effective connectivity | Topological properties | Evoked responses—sensory processing | Spatio-temporal dynamics | |
|---|---|---|---|---|---|
| Propofol | Disruption of within- and between-network functional connectivity in large-scale brain networks (particularly fronto-parietal connectivity; Boveroux et al., 2010) | Reduced amplitude and complexity of long-distance cortical communication (Gómez et al., 2013; Sarasso et al., 2015) | Increased local efficiency (parietal regions; Kim et al., 2016; Lee et al., 2017) | Generalized alteration in short-latency evoked electrocorticographic responses to auditory novelty within higher-order cortical areas, outside the auditory cortex (Nourski et al., 2018) | Alteration of dynamics and directionality of effective connectivity (Lee et al., 2009; Untergehrer et al., 2014; Sanders et al., 2018) |
| Suppression of the complexity of regions sparsely connected with large-scale brain networks (Pappas et al., 2019) | Disruption of effective connectivity in large-scale brain networks (Lee et al., 2009; Boly et al., 2012; Lee et al., 2018; Untergehrer et al., 2014; Guldenmund et al., 2016; Sanders et al., 2018) | Fewer small-world properties (Barttfeld et al., 2015) | Suppression of long-latency responses to novelty (Nourski et al., 2018) | Reduced complexity and randomness of the electroencephalographic signal (Wang et al., 2017; Darracq et al., 2018b) | |
| Disruption of thalamo-cortical connectivity within higher-order networks (Boveroux et al., 2010) | Alteration of effective connectivity in lower-order sensory networks (Gómez et al., 2013) | Limitation of connectivity configuration repertoire (Barttfeld et al., 2015; Cavanna et al., 2018) | Reconfiguration of cortical functional connectivity networks involved in nociception, despite activation of spinal cord and cortex by noxious stimulation (Lichtner et al., 2018a,b) | Synchronization of local activity (Huang et al., 2018) | |
| Preservation of connectivity in lower-order sensory networks (Boveroux et al., 2010) | Traffic of information constrained to inflexible patterns (Mashour, 2018; Uhrig et al., 2018) | Prolongation of long-distance communication timescales (Gómez et al., 2013; Huang et al., 2018) | |||
| Remoteness from criticality, with preserved scale-free organization (Liu et al., 2014; Tagliazucchi et al., 2016; Alonso et al., 2019) | |||||
| Disturbance of posterior parietal hub activity (Lee et al., 2013) | |||||
| Halogenated vapors | Breakdown of functional connectivity in higher-order resting-state consciousness networks (Palanca et al., 2015) | Disruption of fronto-parietal anterior to posterior effective connectivity (Lee et al., 2013) | Limitation of connectivity configuration repertoire (Cavanna et al., 2018; Uhrig et al., 2018) | No information | Augmentation of temporal persistence in neuronal oscillation amplitude (Thiery et al., 2018) |
| Disruption of thalamo-cortical connectivity within higher-order networks (Palanca et al., 2015) | Remoteness from criticality (Lee et al., 2018) | Disruption of intermediate strength spatio-temporal patterns of functional connectivity within and between consciousness networks (Kafashan et al., 2016) | |||
| Preservation of connectivity in lower-order sensory networks (Ranft et al., 2016) | Preservation of higher strength spatio-temporal patterns within networks (Kafashan et al., 2016) | ||||
| Ketamine | Global increase in functional connectivity, with network reorganization (Driesen et al., 2013b) | Disruption of fronto-parietal anterior to posterior effective connectivity (Lee et al., 2013; Vlisides et al., 2017) | No information | TMS-evoked communication complexity close to the waking state (Sarasso et al., 2015) | No information |
| Disruption of functional connectivity in all higher-order consciousness networks but not in the executive control network (Bonhomme et al., 2016) | Reduced alpha power in the precuneus and temporo-parietal junction (possibly related to disconnected consciousness; Vlisides et al., 2018; Darracq et al., 2018a) | ||||
| Preservation of functional connectivity in sensory networks (Bonhomme et al., 2016) | |||||
| Long-term effect on the interactions between the default mode network and networks involved in depression? and restoration of the abnormal connectivity of depressed patients (Li et al., 2018; Vutskits, 2018) | |||||
| Transient effect on working memory network (Driesen et al., 2013a) | |||||
| Dexmedetomidine | Reduced within-network and thalamic connectivity in higher-order consciousness networks (Guldenmund et al., 2017) | No information | Reduced local and global large-scale network efficiency (Hashmi et al., 2017) | No information | No information |
| Preservation of lower-order sensory networks functional connectivity (Guldenmund et al., 2017) | Reduced large-scale network connectivity strength (Hashmi et al., 2017) | ||||
| Better preservation of functional connectivity between thalamus, medial anterior cingulate cortex, and mesopontine area as compared to sleep and propofol unresponsiveness (Guldenmund et al., 2017) | No impairment in node degree (Hashmi et al., 2017) | ||||
| Benzodiazepines | Disruption of higher-order consciousness networks (Greicius et al., 2008; Liang et al., 2018) | Disruption of effective connectivity in large-scale brain networks (Greicius et al., 2008; Ferrarelli et al., 2010; Liang et al., 2018) | No information | Reduced auditory cortex activation by sounds(Frolich et al., 2017) | No information |
| Preservation of lower-order sensory networks (Frolich et al., 2017) | Reduced duration and propagation of evoked TMS cortical response (Ferrarelli et al., 2010) | ||||
| Xenon | No information | No information | Remoteness from criticality (Colombo et al., 2019) | TMS-evoked high amplitude slow waves with low complexity (Sarasso et al., 2015) | Slowing down and smoothing of the temporal profile of the EEG signal (Colombo et al., 2019) |