Modern vision of relationship between theta rhythm and the processes of attention

2021 ◽  
Author(s):  
N.A. Karatygin ◽  
I.I. Korobeinikova ◽  
N.V. Karatygina ◽  
Ya.A. Venerina
Keyword(s):  
Theta Rhythm ◽  
Brain Structures ◽  
Gamma Band ◽  
Theta Band ◽  
Mental Functions ◽  
Gamma Rhythm ◽  
Modern Vision ◽  
Phase Amplitude ◽  
Attention Systems

At present time conceptions of complex neurophysiological mechanisms underlying processes of attention are actively developing. In last few years, several researches revealed rhythmic character of processes of attention. Especially theta-rhythm is considered to be significant in organization of rhythmic interactions between brain zones, which take part in providing attention systems work. The aim of the work – to analyze and summarize modern date about role of theta-rhythm in providing basic processes of attention. The report presents modern data about role of theta-rhythm in processes of attention. Specific features of attention systems are discussed. Thrifold model of attention, developed by Steven E. Petersen and Michael I. Posner is reviewed in detail. Moreover, evidences of rhythmic character of processes of attention are summarized and leading part of theta-activity in providing these processes is demonstrated. We also discuss the investigations by Randolph F. Helfrich and Ian C. Fiebelkorn et al. which stated that the quantization of processes of attention with theta-frequency as a general principle of brain structures activity. Dependence of frequency characteristics of cortex zones of human brain from number of objects of attention is discussed. There is also an analysis of theta-band’s ability to modulate biopotentials of higher frequency. Special attention is paid to the researches focused on theta-gamma coupling. The influence of theta-rhythm phase on gamma-rhythm amplitude in phase-amplitude coupling of theta- and gamma-band is analyzed. Theta-rhythm is considered to be one of the rhythmic components that regulate complex mental functions such as attention, memory and consciousness. Obviously, there is a lack of an exact understanding of the role for every band in mental functions regulation; therefore, more investigations in this field are required. However, several data about the role of theta-band in mental functions was collected. A complex of systems with different physiological and neurochemical basis provides attention. It was demonstrated that attention - is a rhythmical process in which theta-band is a crucial part. Theta-rhythm provides synchronization and joint activity of distant brain structures. Moreover, theta-rhythm modulates high-frequent bands. Theta- gamma-band coupling is supposed to be important for attention. Such cooperation is considered to be an evidence of cortical and subcortical zones and provides coordination of analyzing systems of different level. It is suggested that different phases of theta-band may provide retention/switching of attention or determine information flow. As a summary of review of literary sources, there is a conclusion about high significance of this frequency range in different attention systems functioning.

Theta rhythm, attention and transcranial stimulation method

2021 ◽  
Author(s):  
N.A. Karatygin ◽  
I.I. Korobeinikova
Keyword(s):  
Theta Rhythm ◽  
Brain Plasticity ◽  
Oscillatory Activity ◽  
Transcranial Stimulation ◽  
Memory And Attention ◽  
Gamma Rhythm ◽  
Wide Range ◽  
Stimulation Method ◽  
Stimulation Of

Noninvasive methods of transcranial stimulation in clinical and research activity have become widely applied for the last few years. Due to the high spatial and temporal resolution, these methods allow to explore oscillatory processes that underlie important cognitive functions on a new level. In particular, researchers got an opportunity to influence rhythmic processes, which provide function of attention by these methods. By the way, stimulation of different brain zones with theta-rhythm frequency appears to be interesting, as far as oscillations of attention on this frequency reveal itself both in external activity of subject and in oscillatory activity of neurons and neural ensembles. Aim – analysis and summarize of domestic and foreign researches with usage of transcranial stimulation method to identify role of theta-rhythm in attention processes. Analysis of modern data concerning significance of theta-rhythm in organization of attention processes was performed analyzed. Different modes of transcranial stimulation methods, that allow to discover fundamental role of theta-rhythm in oscillatory activity of neural assembles, which are the base for attention mechanisms were considered. The review noted that the method of transcranial magnetic stimulation (TMS), which is based on the principle of electromagnetic induction with potential excellent temporal and sufficiently decent spatial resolution, is extensively widely used. Usually, TMS is performed with usage single-pulse, paired-pulse, or repetitive rhythmic stimulation. In current review special attention is salaried to the theta burst stimulation protocol. It was suggested that current protocol hypothesizes to influence brain plasticity and simulates the effect of theta-gamma coupling, which is to change the amplitude of the potentials at the frequency of the gamma rhythm depending on the theta wave phase. During the applying of the TMS different variants, several research methodological approaches were applied. Thus, usage of TMS may disrupt functioning in certain cortex areas , also it is possible to increase the oscillatory activity of a particular region at a particular frequency and to enhance or decrease the synchronization of remote cortical areas in a certain frequency range. These approaches may be used directly during the execution of the test task by the subjects or in the period prior the test performing. Many researches show that transcranial stimulation of some zones of cortex contributes to the achievement of better results of examinee in tests on memory and attention. This effect is most often observed while usage of stimulation with theta-rhythm frequency. Improvement of memory and attention functions has high practical meaning for wide range of activity. Understanding of regularities and mechanisms of stimulation with theta-rhythm frequency would allow to create systems and protocols of stimulation, which would effectively improve these functions for the long period.

scholarly journals Phase-based coordination of hippocampal and neocortical oscillations during human sleep

2019 ◽  
Author(s):  
Roy Cox ◽  
Theodor Rüber ◽  
Bernhard P Staresina ◽  
Juergen Fell
Keyword(s):  
Eye Movement ◽  
Brain Structures ◽  
Beta Activity ◽  
Rapid Eye Movement ◽  
Physiological Basis ◽  
Neurosurgical Patients ◽  
High Gamma ◽  
Phase Amplitude ◽  
Frequency Phase

AbstractDuring sleep, new memories undergo a gradual transfer from the hippocampus (HPC) to the neocortex (NC). Precisely timed neural oscillations interacting within and between these brain structures are thought to mediate this sleep-dependent memory consolidation, but exactly which sleep oscillations instantiate the HPC-NC dialog, and via what mechanisms, remains elusive. Employing invasive electroencephalography in ten neurosurgical patients across a full night of sleep, we identified three broad classes of phase-based HPC-NC communication. First, we observed interregional phase synchrony for non-rapid eye movement (NREM) spindles, N2 and rapid eye movement (REM) theta, and N3 beta activity. Second, and most intriguingly, we found asymmetrical N3 cross-frequency phase-amplitude coupling between HPC SOs and NC activity spanning the delta to high-gamma/ripple bands, but not in the opposite direction. Lastly, N2 theta and NREM spindle synchrony were themselves modulated by HPC SOs. These novel forms of phase-based interregional communication emphasize the role of HPC SOs in the HPC-NC dialog, and may offer a physiological basis for the sleep-dependent reorganization of mnemonic content.

scholarly journals A model of the CA1 field rhythms

2021 ◽  
Author(s):  
Mysin I.E.
Keyword(s):  
Entorhinal Cortex ◽  
Theta Rhythm ◽  
Field Potential ◽  
Medial Septum ◽  
Postsynaptic Potentials ◽  
Hippocampal Ca1 ◽  
Gamma Rhythm ◽  
Hippocampal Ca1 Field ◽  
Gamma Rhythms ◽  
Phase Amplitude

AbstractWe propose a model of the main rhythms in the hippocampal CA1 field: theta rhythm, slow, middle, and fast gamma rhythms, and ripples oscillations. We have based this on data obtained from animals behaving freely. We have considered the modes of neuronal discharges and the occurrence of local field potential (LFP) oscillations in the theta and non-theta states at different inputs from the CA3 field, the medial entorhinal cortex, and the medial septum. In our work, we tried to reproduce the main experimental phenomena about rhythms in the CA1 field: the coupling of neurons to the phase of rhythms, cross-rhythm phase-phase and phase-amplitude coupling. Using computational experiments, we have proved the hypothesis that the descending phase of the theta rhythm in the CA1 field is formed by the input from the CA3 field via the Shaffer collaterals, and the ascending phase of the theta rhythm is formed by the inhibitory postsynaptic potentials from CCK basket cells. The slow gamma rhythm is coupled to the descending phase of the theta rhythm, since it also depends on the arrival of the signal via the Shaffer collaterals. The middle gamma rhythm is formed by the excitatory postsynaptic potentials of the principal neurons of the third layer of the entorhinal cortex, corresponds to experimental data. We were able to unite in a single mathematical model several theoretical ideas about the mechanisms of rhythmic processes in the CA1 field of the hippocampus.

The role of serotoninergic brain structures in neurotensin influence mechanism on defensive behavior in rats

2007 ◽  
Author(s):  
N. P. Shugalev ◽  
A. V. Stavrovskaja ◽  
S. Olshanskij ◽  
G. Hartmann ◽  
L. Lenard
Keyword(s):  
Defensive Behavior ◽  
Brain Structures ◽  
Influence Mechanism

scholarly journals GPER-Deficient Rats Exhibit Lower Serum Corticosterone Level and Increased Anxiety-Like Behavior

2020 ◽  
Vol 2020 ◽  
pp. 1-22 ◽  
Author(s):  
Yi Zheng ◽  
Meimei Wu ◽  
Ting Gao ◽  
Li Meng ◽  
Xiaowei Ding ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Corticosterone Level ◽  
Brain Structures ◽  
Ample Evidence ◽  
Genetic Ablation ◽  
Serum Corticosterone ◽  
Underlying Mechanisms ◽  
G Protein Coupled ◽  
Prolonged Stress

Ample evidence suggests that estrogens have strong influences on the occurrence of stress-related mood disorders, but the underlying mechanisms remain poorly understood. Through multiple approaches, we demonstrate that the G protein-coupled estrogen receptor (GPER) is widely distributed along the HPA axis and in brain structures critically involved in mood control. Genetic ablation of GPER in the rat resulted in significantly lower basal serum corticosterone level but enhanced ACTH release in response to acute restraint stress, especially in the female. GPER-/- rats of either sex displayed increased anxiety-like behaviors and deficits in learning and memory. Additionally, GPER deficiency led to aggravation of anxiety-like behaviors following single-prolonged stress (SPS). SPS caused significant decreases in serum corticosterone in WT but not in GPER-deficient rats. The results highlight an important role of GPER at multiple sites in regulation of the HPA axis and mood.

scholarly journals Early oxygen levels contribute to brain injury in extremely preterm infants

2021 ◽  
Author(s):  
Krista Rantakari ◽  
Olli-Pekka Rinta-Koski ◽  
Marjo Metsäranta ◽  
Jaakko Hollmén ◽  
Simo Särkkä ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Brain Structures ◽  
High Oxygen ◽  
List Type ◽  
Neurodevelopmental Outcomes ◽  
Oxygen Levels ◽  
Arterial Blood ◽  
Extremely Preterm ◽  
Extremely Preterm Infants

Abstract Background Extremely low gestational age newborns (ELGANs) are at risk of neurodevelopmental impairments that may originate in early NICU care. We hypothesized that early oxygen saturations (SpO2), arterial pO2 levels, and supplemental oxygen (FiO2) would associate with later neuroanatomic changes. Methods SpO2, arterial blood gases, and FiO2 from 73 ELGANs (GA 26.4 ± 1.2; BW 867 ± 179 g) during the first 3 postnatal days were correlated with later white matter injury (WM, MRI, n = 69), secondary cortical somatosensory processing in magnetoencephalography (MEG-SII, n = 39), Hempel neurological examination (n = 66), and developmental quotients of Griffiths Mental Developmental Scales (GMDS, n = 58). Results The ELGANs with later WM abnormalities exhibited lower SpO2 and pO2 levels, and higher FiO2 need during the first 3 days than those with normal WM. They also had higher pCO2 values. The infants with abnormal MEG-SII showed opposite findings, i.e., displayed higher SpO2 and pO2 levels and lower FiO2 need, than those with better outcomes. Severe WM changes and abnormal MEG-SII were correlated with adverse neurodevelopment. Conclusions Low oxygen levels and high FiO2 need during the NICU care associate with WM abnormalities, whereas higher oxygen levels correlate with abnormal MEG-SII. The results may indicate certain brain structures being more vulnerable to hypoxia and others to hyperoxia, thus emphasizing the role of strict saturation targets. Impact This study indicates that both abnormally low and high oxygen levels during early NICU care are harmful for later neurodevelopmental outcomes in preterm neonates. Specific brain structures seem to be vulnerable to low and others to high oxygen levels. The findings may have clinical implications as oxygen is one of the most common therapies given in NICUs. The results emphasize the role of strict saturation targets during the early postnatal period in preterm infants.

scholarly journals Peptides Derived from Growth Factors to Treat Alzheimer’s Disease

2021 ◽  
Vol 22 (11) ◽  
pp. 6071
Author(s):  
Suzanne Gascon ◽  
Jessica Jann ◽  
Chloé Langlois-Blais ◽  
Mélanie Plourde ◽  
Christine Lavoie ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Growth Factors ◽  
Signaling Pathways ◽  
Brain Structures ◽  
Therapeutic Strategies ◽  
Native Proteins ◽  
Receptor Sites ◽  
The Brain

Alzheimer’s disease (AD) is a devastating neurodegenerative disease characterized by progressive neuron losses in memory-related brain structures. The classical features of AD are a dysregulation of the cholinergic system, the accumulation of amyloid plaques, and neurofibrillary tangles. Unfortunately, current treatments are unable to cure or even delay the progression of the disease. Therefore, new therapeutic strategies have emerged, such as the exogenous administration of neurotrophic factors (e.g., NGF and BDNF) that are deficient or dysregulated in AD. However, their low capacity to cross the blood–brain barrier and their exorbitant cost currently limit their use. To overcome these limitations, short peptides mimicking the binding receptor sites of these growth factors have been developed. Such peptides can target selective signaling pathways involved in neuron survival, differentiation, and/or maintenance. This review focuses on growth factors and their derived peptides as potential treatment for AD. It describes (1) the physiological functions of growth factors in the brain, their neuronal signaling pathways, and alteration in AD; (2) the strategies to develop peptides derived from growth factor and their capacity to mimic the role of native proteins; and (3) new advancements and potential in using these molecules as therapeutic treatments for AD, as well as their limitations.

scholarly journals Consciousness, decision making, and volition: freedom beyond chance and necessity

2021 ◽  
Author(s):  
Hans Liljenström
Keyword(s):  
Decision Making ◽  
Free Will ◽  
Brain Activity ◽  
Brain Structures ◽  
Complex Process ◽  
Neural Information ◽  
Neural Information Processing ◽  
Stochastic Population Model ◽  
The Brain

AbstractWhat is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what “you” decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.

Tuning the brain for novelty detection under emotional threat: the role of specific gamma-band phase synchronization

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S42
Author(s):  
M Garcia-Garcia ◽  
J Yordanova ◽  
V Kolev ◽  
J Dominguez-Borras ◽  
C Escera
Keyword(s):  
Phase Synchronization ◽  
Novelty Detection ◽  
Gamma Band ◽  
The Brain

Pathology, Phenomenology and the Dopamine Hypothesis of Schizophrenia

1987 ◽  
Vol 151 (3) ◽  
pp. 288-301 ◽  
Author(s):  
P. J. McKenna
Keyword(s):  
Prefrontal Cortex ◽  
Basal Ganglia ◽  
Functional Role ◽  
Ventral Striatum ◽  
Brain Structures ◽  
Schizophrenic Symptom ◽  
Dopamine Hypothesis ◽  
Dopamine Innervation

The dopamine hypothesis of schizophrenia implies that positive schizophrenic symptoms should be understandable by reference to brain structures receiving a dopamine innervation, or in terms of the functional role of dopamine itself. The basal ganglia, ventral striatum, septo-hippocampal system, and prefrontal cortex, sites of mesotelencephalic dopamine innervation, are examined and it is argued that their dysfunction could form the basis of particular schizophrenic symptom classes. The postulated involvement of dopamine in reinforcement processes might further assist such interpretations. This type of analysis can be extended to other categories of schizophrenic psychopathology.

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