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Nature Reviews. Neuroscience May 2018Multichannel recording technologies have revealed travelling waves of neural activity in multiple sensory, motor and cognitive systems. These waves can be spontaneously... (Review)
Review
Multichannel recording technologies have revealed travelling waves of neural activity in multiple sensory, motor and cognitive systems. These waves can be spontaneously generated by recurrent circuits or evoked by external stimuli. They travel along brain networks at multiple scales, transiently modulating spiking and excitability as they pass. Here, we review recent experimental findings that have found evidence for travelling waves at single-area (mesoscopic) and whole-brain (macroscopic) scales. We place these findings in the context of the current theoretical understanding of wave generation and propagation in recurrent networks. During the large low-frequency rhythms of sleep or the relatively desynchronized state of the awake cortex, travelling waves may serve a variety of functions, from long-term memory consolidation to processing of dynamic visual stimuli. We explore new avenues for experimental and computational understanding of the role of spatiotemporal activity patterns in the cortex.
Topics: Animals; Brain Waves; Cerebral Cortex; Computer Simulation; Electroencephalography; Humans; Models, Neurological; Neural Pathways
PubMed: 29563572
DOI: 10.1038/nrn.2018.20 -
NeuroImage Apr 2019The identification of biomarkers for the early diagnosis of schizophrenia that could inform novel treatment developments is an important objective of current research.... (Review)
Review
The identification of biomarkers for the early diagnosis of schizophrenia that could inform novel treatment developments is an important objective of current research. This paper will summarize recent work that has investigated changes in oscillatory activity and event-related potentials with Electro/Magnetoencephalography (EEG/MEG) in participants at high-risk for the development of schizophrenia, highlighting disruptions in sensory and cognitive operations prior to the onset of the syndrome. Changes in EEG/MEG-data are consistent with evidence for alterations in Glutamatergic and GABAergic neurotransmission as disclosed by Magnetic Resonance Spectroscopy and brain stimulation, indicating changes in Excitation/Inhibition balance parameters prior to the onset of psychosis. Together these data emphasize the importance of research into neuronal dynamics as a crucial approach to establish functional relationships between impairments in neural circuits and emerging psychopathology that together could be fundamental for early intervention and the identification of novel treatments for emerging psychosis.
Topics: Brain Waves; Electroencephalography; Evoked Potentials; Humans; Magnetoencephalography; Prodromal Symptoms; Schizophrenia
PubMed: 29175199
DOI: 10.1016/j.neuroimage.2017.11.026 -
Neurobiology of Learning and Memory Apr 2019Alternations of up and down can be seen across many different levels during sleep. Neural firing-rates, synaptic markers, molecular pathways, and gene expression all... (Review)
Review
Alternations of up and down can be seen across many different levels during sleep. Neural firing-rates, synaptic markers, molecular pathways, and gene expression all show differential up and down regulation across brain areas and sleep stages. And also the hallmarks of sleep - sleep stage specific oscillations - are characterized themselves by up and down as seen within the slow oscillation or theta cycles. In this review, we summarize the up and down of sleep covering molecules to electrophysiology and present different theories how this up and down could be regulated by the up and down of sleep oscillations. Further, we propose a tentative theory how this differential up and down could contribute to various outcomes of sleep related memory consolidation: enhancement of hippocampal representations of very novel memories and cortical consolidation of memories congruent with previous knowledge-networks.
Topics: Animals; Brain Waves; Gene Expression; Humans; Memory Consolidation; Signal Transduction; Sleep Stages
PubMed: 29544727
DOI: 10.1016/j.nlm.2018.03.013 -
International Journal of... May 2016The present report is a trial to survey analysis and applications of brain oscillations in cognitive impairment for opening the way to a new take off in research on... (Review)
Review
The present report is a trial to survey analysis and applications of brain oscillations in cognitive impairment for opening the way to a new take off in research on brain oscillation. Although the number of papers related to brain oscillations rapidly increases, it is important to indicate the common principles governing the functioning of brain oscillations in the brain and body. Research scientists need a global view on the types of analysis, applications and existing oscillations. Further, scientists dealing with brain oscillations must have some knowledge from theoretical physics, system theory, and also general philosophy. The neuroscientists working on brain oscillations can mentally integrate several papers in the present report, and try to discover new avenues to augment knowledge on brain functions. A new take off in the search of brain oscillations indicates the strong need to survey this brunch of neuroscience in a broad panoply of science.
Topics: Brain; Brain Waves; Connectome; Electroencephalography; Humans; Mental Processes
PubMed: 25660309
DOI: 10.1016/j.ijpsycho.2015.02.007 -
Trends in Neurosciences Jun 2017Brain dynamic changes associated with schizophrenia are largely equivocal, with interpretation complicated by many factors, such as the presence of therapeutic agents... (Review)
Review
Brain dynamic changes associated with schizophrenia are largely equivocal, with interpretation complicated by many factors, such as the presence of therapeutic agents and the complex nature of the syndrome itself. Evidence for a brain-wide change in individual network oscillations, shared by all patients, is largely equivocal, but stronger for lower (delta) than for higher (gamma) bands. However, region-specific changes in rhythms across multiple, interdependent, nested frequencies may correlate better with pathology. Changes in synaptic excitation and inhibition in schizophrenia disrupt delta rhythm-mediated cortico-cortical communication, while enhancing thalamocortical communication in this frequency band. The contrasting relationships between delta and higher frequencies in thalamus and cortex generate frequency mismatches in inter-regional connectivity, leading to a disruption in temporal communication between higher-order brain regions associated with mental time travel.
Topics: Animals; Brain; Brain Waves; Humans; Neural Pathways; Schizophrenia
PubMed: 28515010
DOI: 10.1016/j.tins.2017.04.003 -
Neuroscience and Biobehavioral Reviews Dec 2017Self-awareness is a pivotal component of conscious experience. It is correlated with a paralimbic network of medial prefrontal/anterior cingulate and medial... (Review)
Review
Self-awareness is a pivotal component of conscious experience. It is correlated with a paralimbic network of medial prefrontal/anterior cingulate and medial parietal/posterior cingulate cortical "hubs" and associated regions. Electromagnetic and transmitter manipulation have demonstrated that the network is not an epiphenomenon but instrumental in generation of self-awareness. Thus, transcranial magnetic stimulation (TMS) targeting the hubs impedes different aspects of self-awareness with a latency of 160ms. The network is linked by ∼40Hz oscillations and regulated by dopamine. The oscillations are generated by rhythmic GABA-ergic inhibitory activity in interneurons with an extraordinarily high metabolic rate. The hubs are richly endowed with interneurons and therefore highly vulnerable to disturbed energy supply. Consequently, deficient paralimbic activity and self-awareness are characteristic features of many disorders with impaired oxygen homeostasis. Such disorders may therefore be treated unconventionally by targeting interneuron function.
Topics: Awareness; Brain Waves; Cognition; Cognitive Neuroscience; Consciousness; Humans; Self Concept; Transcranial Magnetic Stimulation
PubMed: 27079562
DOI: 10.1016/j.neubiorev.2016.04.004 -
Neural Plasticity 2019
Topics: Animals; Brain; Brain Waves; Humans; Neuronal Plasticity
PubMed: 31885538
DOI: 10.1155/2019/9403195 -
Current Topics in Behavioral... 2015Schizophrenia is a devastating mental illness with a worldwide prevalence of approximately 1%. Although the clinical features of the disorder were described over one... (Review)
Review
Schizophrenia is a devastating mental illness with a worldwide prevalence of approximately 1%. Although the clinical features of the disorder were described over one hundred years ago, its neurobiology is still largely elusive despite several decades of research. Schizophrenia is associated with marked sleep disturbances and memory impairment. Above and beyond altered sleep architecture, sleep rhythms including slow waves and spindles are disrupted in schizophrenia. In the healthy brain, these rhythms reflect and participate in plastic processes during sleep. This chapter discusses evidence that schizophrenia patients exhibit dysfunction of sleep-mediated plasticity on a behavioral, cellular, and molecular level and offers suggestions on how the study of sleeping brain activity can shed light on the pathophysiological mechanisms of the disorder.
Topics: Brain Waves; Humans; Neuronal Plasticity; Schizophrenia; Sleep Wake Disorders
PubMed: 25608723
DOI: 10.1007/7854_2014_366 -
Current Opinion in Neurobiology Jun 2011The hippocampus, a structure required for many types of memory, connects to the medial prefrontal cortex, an area that helps direct neuronal information streams during... (Review)
Review
The hippocampus, a structure required for many types of memory, connects to the medial prefrontal cortex, an area that helps direct neuronal information streams during intentional behaviors. Increasing evidence suggests that oscillations regulate communication between these two regions. Theta rhythms may facilitate hippocampal inputs to the medial prefrontal cortex during mnemonic tasks and may also integrate series of functionally relevant gamma-mediated cell assemblies in the medial prefrontal cortex. During slow-wave sleep, temporal coordination of hippocampal sharp wave-ripples and medial prefrontal cortex spindles may be an important component of the process by which memories become hippocampus-independent. Studies using rodent models indicate that oscillatory phase-locking is disturbed in schizophrenia, emphasizing the need for more studies of oscillatory synchrony in the hippocampal-prefrontal network.
Topics: Animals; Brain Mapping; Brain Waves; Electroencephalography; Hippocampus; Humans; Neural Pathways; Periodicity; Prefrontal Cortex
PubMed: 21571522
DOI: 10.1016/j.conb.2011.04.006 -
The Journal of Neuroscience : the... Jan 2017It is possible that one of the essential functions of sleep is to take out the garbage, as it were, erasing and "forgetting" information built up throughout the day that... (Review)
Review
It is possible that one of the essential functions of sleep is to take out the garbage, as it were, erasing and "forgetting" information built up throughout the day that would clutter the synaptic network that defines us. It may also be that this cleanup function of sleep is a general principle of neuroscience, applicable to every creature with a nervous system.
Topics: Animals; Brain; Brain Waves; Humans; Memory Consolidation; Sleep; Sleep, REM
PubMed: 28100731
DOI: 10.1523/JNEUROSCI.0820-16.2017