- MeSH
- Neurons * MeSH
- Synapses * MeSH
- Publication type
- Journal Article MeSH
In order to refine the analysis of the computational power of discrete-time recurrent neural networks (NNs) between the binary-state NNs which are equivalent to finite automata (level 3 in the Chomsky hierarchy), and the analog-state NNs with rational weights which are Turing-complete (Chomsky level 0), we study an intermediate model αANN of a binary-state NN that is extended with α≥0 extra analog-state neurons. For rational weights, we establish an analog neuron hierarchy 0ANNs ⊂ 1ANNs ⊂ 2ANNs ⊆ 3ANNs and separate its first two levels. In particular, 0ANNs coincide with the binary-state NNs (Chomsky level 3) being a proper subset of 1ANNs which accept at most context-sensitive languages (Chomsky level 1) including some non-context-free ones (above Chomsky level 2). We prove that the deterministic (context-free) language L#={0n1n∣n≥1} cannot be recognized by any 1ANN even with real weights. In contrast, we show that deterministic pushdown automata accepting deterministic languages can be simulated by 2ANNs with rational weights, which thus constitute a proper superset of 1ANNs. Finally, we prove that the analog neuron hierarchy collapses to 3ANNs by showing that any Turing machine can be simulated by a 3ANN having rational weights, with linear-time overhead.
INTRODUCTION: Proteins released to the circulation from affected glial (neuron specific enolasis, NSE) or ganglial cells (S-100b protein) during traumatic brain injury might be used in diagnosis of traumatic brain injury in cases with negative finding on computer tomography scan (concussion) or in patients where the serious clinical status does not corresponde with mild changes on CT scan (diffuse axonal injury, DAI). Classification of DAI according Gennarelli considered the concussion as lower degree of DAI. MATERIALS AND METHOD: 15 patients were divided into group I of mild conccussion (n=3) with 1-day duration of hospitalisation, group II of serious concussion (n=4) with more days duration of hospitalisation with negative findings on CT scan and group III of patients with diagnosis of DAI (n=8). Blood samples were investigated by immunoanalysis for NSE and protein S-100b (Elecsys 2010, Roche). RESULTS: Values of NSE (16.30 +/- 2.33 vs. 110.48 +/- 34.99 vs. 24.07 +/- 6.29 microg/l), and protein S-100b (0.207 +/- 0.03 vs. 0.945 +/- 0.69 vs. 0.736 +/- 0.36 microg/l) overdrow the reference value in cases of group I, II, and III. We discuss the biomechanics of trauma and the blood brain barrier damage in comparison with values of NSE and S-100b protein. CONCLUSION: [corrected] We proved the significantly higher values of the NSE in group of serious concussion compared to group of DAI. We demonstrated that concussions in some cases lead to serious damage of health.
- MeSH
- Biomarkers blood MeSH
- Diffuse Axonal Injury diagnosis MeSH
- Phosphopyruvate Hydratase blood MeSH
- Brain Concussion complications diagnosis MeSH
- Humans MeSH
- Nerve Growth Factors blood MeSH
- Prognosis MeSH
- S100 Proteins blood MeSH
- S100 Calcium Binding Protein beta Subunit MeSH
- Check Tag
- Humans MeSH
- Publication type
- English Abstract MeSH
- Journal Article MeSH
- Names of Substances
- Biomarkers MeSH
- Phosphopyruvate Hydratase MeSH
- Nerve Growth Factors MeSH
- S100 Proteins MeSH
- S100 Calcium Binding Protein beta Subunit MeSH
BACKGROUND/AIMS: The determination of neuron-specific enolase (NSE) is relatively frequently requested in the differential diagnosis of small-cell lung carcinoma and non-small-cell lung carcinoma. The individual results of different immunoassays are often not comparable, which has been confirmed by long-term external quality assessments. In this study, we assessed the possible sources of these differences. METHODS: More than 3,000 NSE analyses were performed using seven different immunoassays: DELFIA (PerkinElmer), Elecsys 2010 or Modular Analytics E 170 (Roche), Kryptor (B.R.A.H.M.S.), the enzyme-linked immunosorbent assay DRG and three assays based on immunoradiometric assays (DiaSorin, Immunotech and Schering-CIS). The following parameters were evaluated: precision profile of the individual methods, linearity on dilution and modified recovery, comparability and discrimination of immunoassays, sensitivity, and specificity. RESULTS: There were differences in the correlation of values of certain low-concentration specimens. Some assays correlate well while others do not (up to fivefold difference), especially in the case of controls prepared synthetically. Therefore, the current non-standardized preparation of controls is questionable in our opinion. In the cutoff range, the difference in the results of native samples did not exceed its double value. The variation in values >100 microg/l obtained with different assays is <40%. CONCLUSION: Our results confirmed expected matrix interferences especially in the range of normal and cutoff NSE concentrations. Another source of discrepancies can be attributed to different antibody affinity to alphagamma- and gammagamma-enolase isoenzymes. Finally, improper settings of cutoff values also contribute to the different discrimination of the methods.
- MeSH
- Adenocarcinoma blood enzymology MeSH
- Biological Assay * MeSH
- Enzyme-Linked Immunosorbent Assay MeSH
- Phosphopyruvate Hydratase blood MeSH
- Humans MeSH
- Carcinoma, Small Cell blood enzymology MeSH
- Biomarkers, Tumor metabolism MeSH
- Lung Neoplasms blood enzymology MeSH
- Carcinoma, Non-Small-Cell Lung blood enzymology MeSH
- Sensitivity and Specificity MeSH
- Carcinoma, Squamous Cell blood enzymology MeSH
- Case-Control Studies MeSH
- Carcinoma, Large Cell blood enzymology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, N.I.H., Extramural MeSH
- Comparative Study MeSH
- Names of Substances
- Phosphopyruvate Hydratase MeSH
- Biomarkers, Tumor MeSH
In order to understand how olfactory stimuli are encoded and processed in the brain, it is important to build a computational model for olfactory receptor neurons (ORNs). Here, we present a simple and reliable mathematical model of a moth ORN generating spikes. The model incorporates a simplified description of the chemical kinetics leading to olfactory receptor activation and action potential generation. We show that an adaptive spike threshold regulated by prior spike history is an effective mechanism for reproducing the typical phasic-tonic time course of ORN responses. Our model reproduces the response dynamics of individual neurons to a fluctuating stimulus that approximates odorant fluctuations in nature. The parameters of the spike threshold are essential for reproducing the response heterogeneity in ORNs. The model provides a valuable tool for efficient simulations of olfactory circuits.
- Keywords
- adaptive threshold, integrate-and-fire model, olfactory receptor neuron,
- MeSH
- Action Potentials physiology MeSH
- Models, Biological MeSH
- Olfactory Receptor Neurons drug effects physiology MeSH
- Electrophysiological Phenomena MeSH
- Adaptation, Physiological * MeSH
- Moths physiology MeSH
- Sex Attractants pharmacology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Sex Attractants MeSH
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative condition characterised by a progressive loss of motor neurons controlling voluntary muscle activity. The disease manifests through a variety of motor dysfunctions related to the extent of damage and loss of neurons at different anatomical locations. Despite extensive research, it remains unclear why some motor neurons are especially susceptible to the disease, while others are affected less or even spared. In this article, we review the neurobiological mechanisms, neurochemical profiles, and morpho-functional characteristics of various motor neuron groups and types of motor units implicated in their differential exposure to degeneration. We discuss specific cell-autonomous (intrinsic) and extrinsic factors influencing the vulnerability gradient of motor units and motor neuron types to ALS, with their impact on disease manifestation, course, and prognosis, as revealed in preclinical and clinical studies. We consider the outstanding challenges and emerging opportunities for interpreting the phenotypic and mechanistic variability of the disease to identify targets for clinical interventions.
- Keywords
- Bulbar and spinal ALS, Excitotoxicity, Motor neuron disease, Motor units, SOD1 mutation, Skeletal and visceral muscles, TDP43,
- MeSH
- Amyotrophic Lateral Sclerosis * MeSH
- Humans MeSH
- Disease Models, Animal MeSH
- Motor Neurons MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Neuroinflammation plays an important role in the pathogenesis of epilepsy, so it is necessary to clarify the influence of standard antiepileptic drugs as well as adjuvant agents (e.g., cardiac glycoside digoxin, which previously showed a clear anticonvulsant potential) on cyclooxygenase pathway and neuron-specific enolase under the conditions of chronic epileptogenesis. The aim of the article is to determine the effect of digoxin, sodium valproate, and celecoxib per se, as well as the combination of digoxin with sodium valproate on the content of cyclooxygenase 1 and 2 types, prostaglandins E2, F2α, I2, thromboxane B2, 8-isoprostane and neuron-specific enolase in the brain of mice in the pentylenetetrazole-induced kindling model. It was found that only the combination of sodium valproate with digoxin provides a complete protective effect (absence of seizures) and shows the clearest influence on neuroinflammation markers and neuronal damage than monotherapy with each of these drugs and celecoxib, which appeared to be an ineffective anticonvulsant. The obtained results indicate that digoxin is a promising adjuvant drug to classical antiepileptic drugs (mostly sodium valproate) in epilepsy treatment.c.
- Keywords
- pentylenetetrazole-induced kindling, celecoxib, cyclooxygenase, digoxin, neuron-specific enolase, valproate,
- MeSH
- Anticonvulsants pharmacology therapeutic use MeSH
- Celecoxib pharmacology therapeutic use MeSH
- Prostaglandin-Endoperoxide Synthases therapeutic use MeSH
- Digoxin therapeutic use MeSH
- Epilepsy * chemically induced drug therapy MeSH
- Phosphopyruvate Hydratase therapeutic use MeSH
- Rats MeSH
- Valproic Acid * pharmacology therapeutic use MeSH
- Mice MeSH
- Neuroinflammatory Diseases MeSH
- Pentylenetetrazole pharmacology therapeutic use MeSH
- Rats, Wistar MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anticonvulsants MeSH
- Celecoxib MeSH
- Prostaglandin-Endoperoxide Synthases MeSH
- Digoxin MeSH
- Phosphopyruvate Hydratase MeSH
- Valproic Acid * MeSH
- Pentylenetetrazole MeSH
BACKGROUND: Despite marked advances in intensive cardiology care, current options for outcome prediction in cardiac arrest survivors remain significantly limited. The aim of our study was, therefore, to compare the day-specific association of neuron-specific enolase (NSE) with outcomes in out-of-hospital cardiac arrest (OHCA) survivors treated with hypothermia. METHODS: Eligible patients were OHCA survivors treated with targeted temperature management at 33 °C for 24 h using an endovascular device. Blood samples for NSE levels measurement were drawn on days 1, 2, 3, and 4 after hospital admission. Thirty-day neurological outcomes according to the Cerebral Performance Category (CPC) scale and 12-month mortality were evaluated as clinical end points. RESULTS: A total of 153 cardiac arrest survivors (mean age 64.2 years) were enrolled in the present study. Using ROC analysis, optimal cutoff values of NSE for prediction of CPC 3-5 score on specific days were determined as: day 1 > 20.4 mcg/L (sensitivity 63.3%; specificity 82.1%; P = 0.002); day 2 > 29.0 mcg/L (72.5%; 94.4%; P < 0.001); and day 3 > 20.7 mcg/L (94.4%; 86.7%; P < 0.001). The highest predictive value, however, was observed on day 4 > 19.4 mcg/L (93.5%; 91.0%; P < 0.001); NSE value >50.2 mcg/L at day 4 was associated with poor outcome with 100% specificity and 42% sensitivity. Moreover, NSE levels measured on all individual days also predicted 12-month mortality (P < 0.001); the highest predictive value for death was observed on day 3 > 18.1 mcg/L (85.3%; 72.0%; P < 0.001). Significant association with prognosis was found also for changes in NSE at different time points. An NSE level on day 4 > 20.0 mcg/L, together with a change > 0.0 mcg/L from day 3 to day 4, predicted poor outcome (CPC 3-5) with 100% specificity and 73% sensitivity. CONCLUSIONS: Our results suggest that NSE levels are a useful tool for predicting 30-day neurological outcome and long-term mortality in OHCA survivors treated with targeted temperature management at 33 °C. The highest associations of NSE with outcomes were observed on day 4 and day 3 after cardiac arrest.
- Keywords
- Cardiac arrest, Mild hypothermia, Neuron-specific enolase, Prognosis,
- MeSH
- Biomarkers analysis blood MeSH
- Phosphopyruvate Hydratase analysis blood MeSH
- Risk Assessment methods MeSH
- Intensive Care Units organization & administration statistics & numerical data MeSH
- Middle Aged MeSH
- Humans MeSH
- Models, Neurological MeSH
- Neurologic Examination methods MeSH
- Prognosis MeSH
- Prospective Studies MeSH
- ROC Curve MeSH
- Aged MeSH
- Out-of-Hospital Cardiac Arrest mortality MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Biomarkers MeSH
- Phosphopyruvate Hydratase MeSH
- MeSH
- Humans MeSH
- Nerve Net MeSH
- Neurons * MeSH
- Synapses * MeSH
- Models, Theoretical * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The concept of coding efficiency holds that sensory neurons are adapted, through both evolutionary and developmental processes, to the statistical characteristics of their natural stimulus. Encouraged by the successful invocation of this principle to predict how neurons encode natural auditory and visual stimuli, we attempted its application to olfactory neurons. The pheromone receptor neuron of the male moth Antheraea polyphemus, for which quantitative properties of both the natural stimulus and the reception processes are available, was selected. We predicted several characteristics that the pheromone plume should possess under the hypothesis that the receptors perform optimally, i.e., transfer as much information on the stimulus per unit time as possible. Our results demonstrate that the statistical characteristics of the predicted stimulus, e.g., the probability distribution function of the stimulus concentration, the spectral density function of the stimulation course, and the intermittency, are in good agreement with those measured experimentally in the field. These results should stimulate further quantitative studies on the evolutionary adaptation of olfactory nervous systems to odorant plumes and on the plume characteristics that are most informative for the 'sniffer'. Both aspects are relevant to the design of olfactory sensors for odour-tracking robots.
- MeSH
- Action Potentials physiology MeSH
- Smell physiology MeSH
- Olfactory Receptor Neurons physiology MeSH
- Olfactory Pathways physiology MeSH
- Models, Neurological * MeSH
- Moths physiology MeSH
- Computer Simulation MeSH
- Sex Attractants physiology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Sex Attractants MeSH
