scholarly journals A New Approach to High-Order Electroencephalogram Phase Analysis Details the Mathematical Mechanisms of Central Nervous System Impulse Encoding

2021 ◽  
Vol 1 (1) ◽  
pp. 1-34
Author(s):  
Ricardo Simeoni
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Human Subjects ◽  
High Order ◽  
Eeg Analysis ◽  
Accessible Information ◽  
Analysis Technique ◽  
Clinical Scenarios ◽  
Shift Keying ◽  
Common Fractions

This paper presents a new electroencephalogram (EEG) analysis technique which is applied to example EEGs pertaining to nine human subjects and a broad spectrum of clinical scenarios. While focusing on technique physical efficacy, the paper also paves the way for future clinically-focused studies with revelations of several quantified and detailed findings in relation to high-order central nervous system communicative impulse encoding akin to a sophisticated form of phase-shift keying. The fact that fine encoding details are extracted with confidence from a seemingly modest EEG set supports the paper’s position that vast amounts of accessible information currently goes unrecognised by conventional EEG analysis. The technique commences with high resolution Fourier analysis being twice applied to an EEG, providing newly-identified harmonics. Except for deep sleep where harmonic phase, φ, behaviour becomes highly linear, φ transitional values, ∆φ, measured between harmonics of progressively increasing order are found to cluster rather than follow a normal distribution (e.g., χ2 = 303, df = 12, p < 0.001). Clustering is categorised into ten Families for which many separations between ∆φ values are writable in terms of k = j/4 or j/3 (j = 1, 2, 3 ...), with a preference for k = j/2 (χ2 = 77, df = 1, p < 0.001), amounts of a Family-specific quantum increment value, α∆φ. A parabolic relationship (r > 0.9999, p < 0.001) exists between α∆φ (and the parabola minimum associates with an additional inter-Family or universal quantum increment value, αmin). Ratios of α∆φ typically align within ± 0.5% of simple common fractions (95% CI).

Combined Blockade of Cholinergic Receptors Shifts the Brain from Stimulus Encoding to Memory Consolidation

2006 ◽  
Vol 18 (5) ◽  
pp. 793-802 ◽  
Author(s):  
Björn H. Rasch ◽  
Jan Born ◽  
Steffen Gais
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Memory Consolidation ◽  
Declarative Memory ◽  
Sleep Stage ◽  
Human Subjects ◽  
Memory Encoding ◽  
Cholinergic Neurotransmission ◽  
Cholinergic Tone ◽  
The Brain

High central nervous system levels of acetylcholine (ACh) are commonly regarded as crucial for learning and memory, and a decline in cholinergic neurotransmission is associated with Alzheimer's dementia. However, recent findings revealed exceptions to this rule: The low ACh tone characterizing slowwave sleep (SWS) has proven necessary for consolidation of hippocampus-dependent declarative memories during this sleep stage. Such observations, together with recent models of a hippocampal-neocortical dialogue underlying systems memory consolidation, suggest that high levels of ACh support memory encoding, whereas low levels facilitate consolidation. We tested this hypothesis in human subjects by blocking cholinergic neurotransmission during wakefulness, starting 30 min after learning. Subjects received the muscarinic antagonist scopolamine (4 µg/kg bodyweight intravenously) and the nicotinic antagonist mecamylamine (5 mg orally). Compared to placebo, combined muscarinic and nicotinic receptor blockade significantly improved consolidation of declarative memories tested 10 hr later, but simultaneously impaired acquisition of similar material. Consolidation of procedural memories, which are not dependent on hippocampal functioning, was unaffected. Neither scopolamine nor mecamylamine alone enhanced declarative memory consolidation. Our findings support the notion that ACh acts as a switch between modes of acquisition and consolidation. We propose that the natural shift in central nervous system cholinergic tone from high levels during wakefulness to minimal levels during SWS optimizes declarative memory consolidation during a period with no need for new memory encoding.

STEREOTACTIC RADIOSURGERY: ADJACENT TISSUE INJURY AND RESPONSE AFTERHIGH-DOSE SINGLE FRACTION RADIATION

Neurosurgery ◽  
2007 ◽  
Vol 60 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Bryan C. Oh ◽  
Paul G. Pagnini ◽  
Michael Y. Wang ◽  
Charles Y. Liu ◽  
Paul E. Kim ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Tissue Injury ◽  
Molecular Data ◽  
Benign Tumors ◽  
Normal Brain ◽  
Clinical Scenarios ◽  
The Central Nervous System ◽  
Brain Parenchymal ◽  
The Brain

Abstract RADIOSURGERY IS NOW the preferred treatment modality for many intracranial disease processes. Although almost 50 years have passed since it was introduced as a tool to treat neurological disease, investigations into its effects on normal tissues of the central nervous system are still ongoing. The need for these continuing studies must be underscored. A fundamental understanding of the brain parenchymal response to radiosurgery would permit development of strategies that would enhance and potentiate the radiosurgical treatment effects on diseased tissue while mitigating injury to normal structures. To date, most studies on the response of the central nervous system to radiosurgery have been performed on brain tissue in the absence of pathological lesions, such as benign tumors or metastases. Although instructive, these investigations fail to emulate the majority of clinical scenarios that involve radiosurgical treatment of specific lesions surrounded by normal brain parenchyma. This article is the first in a two-part series that addresses the brain parenchyma's response to radiosurgery. This first article analyzes the histological, radiographic, and molecular data gathered regarding the brain parenchymal response to radiosurgery and aims to suggest future studies that could enhance our understanding of the topic. The second article in the series begins by discussing strategies for radiosurgical therapeutic enhancement. It concludes by focusing on strategies for mitigation and repair of radiation-induced brain injury.

Injury Detection for Central Nervous System via EEG with Higher Order Crossing-based Methods

2000 ◽  
Vol 39 (02) ◽  
pp. 171-174
Author(s):  
T. Qiu ◽  
X. Kong
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Dominant Frequency ◽  
Higher Order ◽  
Eeg Signal ◽  
Eeg Analysis ◽  
Eeg Spectrum ◽  
Processed Eeg ◽  
Spectrum Characteristics ◽  
Detection And Quantification

Abstract:Higher order crossing (HOC) is a powerful tool for time series analysis. Two HOC-based EEG analysis methods are developed for brain injury detection and quantification. The first method explores EEG spectrum characteristics via an estimate of the dominant frequency of a pre-processed EEG signal. The second method is based on the norm of the AHOC, an HOC obtained from the -filter prefiltered EEG signal. Both methods are shown to be effective in detecting hypoxic/asphyxic injuries as well as assessing the severity of the injury.

scholarly journals Update in the CNS Response to Hypoglycemia

2012 ◽  
Vol 97 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Rory J. McCrimmon
Keyword(s):  
Type 2 Diabetes ◽  
Central Nervous System ◽  
Type 1 Diabetes ◽  
Nervous System ◽  
Animal Studies ◽  
Human Subjects ◽  
Diabetes Research ◽  
The Central Nervous System

Hypoglycemia remains a major clinical issue in the management of people with type 1 and type 2 diabetes. Research in basic science is only beginning to unravel the mechanisms that: 1) underpin the detection of hypoglycemia and initiation of a counterregulatory defense response; and 2) contribute to the development of defective counterregulation in both type 1 and type 2 diabetes, particularly after prior exposure to repeated hypoglycemia. In animal studies, the central nervous system has emerged as key to these processes. However, bench-based research needs to be translated through studies in human subjects as a first step to the future development of clinical intervention. This Update reviews studies published in the last 2 yr that examined the central nervous system effects of hypoglycemia in human subjects, largely through neuroimaging techniques, and compares these data with those obtained from animal studies and the implications for future therapies. Based on these studies, it is increasingly clear that our understanding of how the brain responds and adapts to recurrent hypoglycemia remains very limited. Current therapies have provided little evidence that they can prevent severe hypoglycemia or improve hypoglycemia awareness in type 1 diabetes. There remains an urgent need to increase our understanding of how and why defective counterregulation develops in type 1 diabetes in order for novel therapeutic interventions to be developed and tested.

Neurotropic enteroviruses co-opt “fair-weather-friend” commensal gut microbiota to drive host infection and central nervous system disturbances

2019 ◽  
Vol 42 ◽  
Author(s):  
Kevin B. Clark
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Gut Bacteria ◽  
Infection Cycle ◽  
Fair Weather ◽  
Host Health ◽  
Microbe Interactions ◽  
Animal Hosts ◽  
Host Infection ◽  
Neuropsychiatric Conditions

Abstract Some neurotropic enteroviruses hijack Trojan horse/raft commensal gut bacteria to render devastating biomimicking cryptic attacks on human/animal hosts. Such virus-microbe interactions manipulate hosts’ gut-brain axes with accompanying infection-cycle-optimizing central nervous system (CNS) disturbances, including severe neurodevelopmental, neuromotor, and neuropsychiatric conditions. Co-opted bacteria thus indirectly influence host health, development, behavior, and mind as possible “fair-weather-friend” symbionts, switching from commensal to context-dependent pathogen-like strategies benefiting gut-bacteria fitness.

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