The thalamocortical network as a single slow wave-generating unit

Crunelli, Vincenzo; David, François; Lőrincz, Magor L.; Hughes, Stuart W.

doi:10.1016/j.conb.2014.09.001

Cited by 145 publications

(152 citation statements)

References 66 publications

(67 reference statements)

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“…Low-frequency activity is a key contributor to integrate longrange interactions within thalamocortical-thalamic networks (21,(51)(52)(53). A recent study investigated the relationship between single neuron spiking activity and brain-wide cortical calcium dynamics (54).…”

Section: Discussionmentioning

confidence: 99%

Low-frequency hippocampal–cortical activity drives brain-wide resting-state functional MRI connectivity

Chan

Leong

et al. 2017

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

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The hippocampus, including the dorsal dentate gyrus (dDG), and cortex engage in bidirectional communication. We propose that low-frequency activity in hippocampal-cortical pathways contributes to brain-wide resting-state connectivity to integrate sensory information. Using optogenetic stimulation and brain-wide fMRI and resting-state fMRI (rsfMRI), we determined the large-scale effects of spatiotemporal-specific downstream propagation of hippocampal activity. Low-frequency (1 Hz), but not high-frequency (40 Hz), stimulation of dDG excitatory neurons evoked robust cortical and subcortical brain-wide fMRI responses. More importantly, it enhanced interhemispheric rsfMRI connectivity in various cortices and hippocampus. Subsequent local field potential recordings revealed an increase in slow oscillations in dorsal hippocampus and visual cortex, interhemispheric visual cortical connectivity, and hippocampal-cortical connectivity. Meanwhile, pharmacological inactivation of dDG neurons decreased interhemispheric rsfMRI connectivity. Functionally, visually evoked fMRI responses in visual regions also increased during and after low-frequency dDG stimulation. Together, our results indicate that low-frequency activity robustly propagates in the dorsal hippocampal-cortical pathway, drives interhemispheric cortical rsfMRI connectivity, and mediates visual processing.hippocampus | resting-state functional connectivity | optogenetic | fMRI | low frequency T he hippocampus (HP) plays a prominent role in central nervous system functions, particularly in episodic memory (1, 2) and spatial navigation (3, 4). The HP, including the dentate gyrus (DG), can evoke large-scale influences on cortical activity, because the HP receives convergent information from sensory and limbic cortices before sending reciprocal divergent projections to create a highly interactive corticohippocampal-cortical network. The HP, including DG, CA3, and CA1, and neocortex, are connected via the entorhinal cortex (EC) (5, 6), such that the dorsolateral-to-ventromedial projection that originates in the EC corresponds to a dorsoventral axis of termination in the HP (5). This anatomical topography suggests that a functional gradient could exist along the HP dorsoventral axis. Previous studies demonstrated that dorsal HP (dHP) and cortex are functionally integrated during sensory processing and memory consolidation (7-9). Specifically, dHP can integrate multimodal sensory information and process memory operations (7) using excitatory longrange projections (10). This process occurs over multiple brain circuits, but the role of dHP in complex networks, particularly its influence on brain-wide functional connectivity, is not well understood.Resting-state functional MRI (rsfMRI) (11-14) provides an invaluable, noninvasive imaging technique to map long-range, brain-wide functional connectivity networks based on the temporal coherence of infraslow (0.005-0.1 Hz) blood oxygen level dependent (BOLD) activity. The functional relevance of specific brain-wide networks in co...

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Section: Discussionmentioning

confidence: 99%

Low-frequency hippocampal–cortical activity drives brain-wide resting-state functional MRI connectivity

Chan

Leong

et al. 2017

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

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“…However, empirical data and analyses to evaluate this hypothesis have been lacking. The role of the thalamus in generating slow and δ oscillations observed during nonrapid eye movement sleep and some states of anesthesiainduced altered consciousness has been a topic of much debate (21). Recordings in deafferented cortex show that slow oscillations can occur in the absence of thalamic connections (22).…”

Section: Layers Of Prefrontal Cortex Are Differentially Affected By Pmentioning

confidence: 99%

“…Electroencephalogram (EEG) recordings in humans during gradual induction of unconsciousness with propofol show the appearance of frontal β oscillations (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) at the onset of sedation, followed by the appearance of coherent frontal α (8-12 Hz) oscillations (7)(8)(9)(10) and widespread slow (0.1-1 Hz) and δ (1-4 Hz) oscillations (7,11,12) when subjects no longer respond to sensory stimuli. Biophysical models of neuronal dynamics have shown that whereas α and β oscillations can be generated by propofol's actions in cortex alone (13), coherent α oscillations require the participation of both thalamus and cortex (14).…”

mentioning

confidence: 99%

Thalamocortical synchronization during induction and emergence from propofol-induced unconsciousness

Flores

Hartnack

Fath

et al. 2017

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

151

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General anesthesia (GA) is a reversible drug-induced state of altered arousal required for more than 60,000 surgical procedures each day in the United States alone. Sedation and unconsciousness under GA are associated with stereotyped electrophysiological oscillations that are thought to reflect profound disruptions of activity in neuronal circuits that mediate awareness and cognition. Computational models make specific predictions about the role of the cortex and thalamus in these oscillations. In this paper, we provide in vivo evidence in rats that alpha oscillations (10-15 Hz) induced by the commonly used anesthetic drug propofol are synchronized between the thalamus and the medial prefrontal cortex. We also show that at deep levels of unconsciousness where movement ceases, coherent thalamocortical delta oscillations (1-5 Hz) develop, distinct from concurrent slow oscillations (0.1-1 Hz). The structure of these oscillations in both cortex and thalamus closely parallel those observed in the human electroencephalogram during propofol-induced unconsciousness. During emergence from GA, this synchronized activity dissipates in a sequence different from that observed during loss of consciousness. A possible explanation is that recovery from anesthesiainduced unconsciousness follows a "boot-up" sequence actively driven by ascending arousal centers. The involvement of medial prefrontal cortex suggests that when these oscillations (alpha, delta, slow) are observed in humans, self-awareness and internal consciousness would be impaired if not abolished. These studies advance our understanding of anesthesia-induced unconsciousness and altered arousal and further establish principled neurophysiological markers of these states.anesthesia | prefrontal cortex | thalamus | coherence | propofol G eneral anesthesia (GA) is a reversible drug-induced state consisting of unconsciousness, analgesia, amnesia, akinesia, and physiological stability (1). In the United States nearly 60,000 surgical procedures are conducted under GA every day, making GA one of the most common manipulations of the brain and central nervous system in medicine (1). The molecular mechanisms by which anesthetic drugs alter brain function have been well characterized (2, 3). Detailed analyses of neural circuitand systems-level mechanisms of GA are more recent (1, 4, 5). Understanding the system-wide effects of anesthetic drugs is necessary in order to understand how these drugs produce states of altered arousal and unconsciousness.One of the most commonly used anesthetic drugs is 2,6-diisopropylphenol (propofol), a GABA-A receptor agonist (6). Electroencephalogram (EEG) recordings in humans during gradual induction of unconsciousness with propofol show the appearance of frontal β oscillations (15-30 Hz) at the onset of sedation, followed by the appearance of coherent frontal α (8-12 Hz) oscillations (7-10) and widespread slow (0.1-1 Hz) and δ (1-4 Hz) oscillations (7, 11, 12) when subjects no longer respond to sensory stimuli. Biophysical models of neuronal dy...

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“…Thalamocortical unit activity underlies the generation of slow oscillation, one of the most important brain processes participating in generation of sleep (Crunelli et al, 2015). Slow wave activity in humans showed alternating neuronal excitation and inhibition patterns identified previously in animal models as upstates and downstates Csercsa et al, 2010;Nobili et al, 2012;Peyrache et al, 2012;Staba, C. L. Wilson, Bragin, Fried and Engel, 2002a).…”

Section: Testing Normal Functions In Epileptic Patientsmentioning

confidence: 75%

Intracranial neuronal ensemble recordings and analysis in epilepsy

Tóth

Fabó

Entz

et al. 2016

Journal of Neuroscience Methods

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Pathological neuronal firing was demonstrated 50 years ago as the hallmark of epileptically transformed cortex with the use of implanted microelectrodes. Since then, microelectrodes remained only experimental tools in humans to detect unitary neuronal activity to reveal physiological and pathological brain functions. This recording technique has evolved substantially in the past few decades; however, based on recent human data implying their usefulness as diagnostic tools, we expect a substantial increase in the development of microelectrodes in the near future.Here, we review the technological background and history of microelectrode array development for human examinations in epilepsy, including discussions on of wire-based and microelectrode arrays fabricated using micro-electro-mechanical system (MEMS) techniques and novel future techniques to record neuronal ensemble.We give an overview of clinical and surgical considerations, and try to provide a list of probes on the market with their availability for human recording. 2Then finally, we briefly review the literature on modulation of single neuron for the treatment of epilepsy, and highlight the current topics under examination that can be background for the future development.3

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The thalamocortical network as a single slow wave-generating unit

Cited by 145 publications

References 66 publications

Low-frequency hippocampal–cortical activity drives brain-wide resting-state functional MRI connectivity

Low-frequency hippocampal–cortical activity drives brain-wide resting-state functional MRI connectivity

Thalamocortical synchronization during induction and emergence from propofol-induced unconsciousness

Intracranial neuronal ensemble recordings and analysis in epilepsy

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