RESUMEN
Aging and genetic predisposition are major risk factors in age-related neurodegenerative disorders. The most common neurodegenerative disorder is Alzheimer's disease (AD). Genome-wide association studies (GWAS) have identified statistically significant association of the PICALM rs3851179 polymorphism with AD. The PICALM G allele increases the risk of AD, while the A allele has a protective effect. We examined the association of the PICALM rs3851179 polymorphism with parameters of the P3 component of auditory event-related potentials (ERPs) in 87 non-demented volunteers (age, 19-77 years) subdivided into two cohorts younger and older than 50 years of age. We found statistically significant association between the AD risk variant PICALM GG and increase in the P3 latency in subjects over 50 years old. The age-dependent increase in the P3 latency was more pronounced in the PICALM GG carriers than in the carriers of the PICALM AA and PICALM AG genotypes. The observed PICALM-associated changes in the neurophysiological processes indicate a decline in the information processing speed with aging due, probably, to neuronal dysfunction and subclinical neurodegeneration of the neuronal networks in the hippocampus and the frontal and parietal cortical areas. Such changes were less pronounced in the carriers of the PICALM gene A allele, which might explain the protective effect of this allele in the cognitive decline and AD development.
Asunto(s)
Envejecimiento/genética , Enfermedad de Alzheimer/patología , Potenciales Evocados/fisiología , Proteínas de Ensamble de Clatrina Monoméricas/genética , Adulto , Anciano , Alelos , Enfermedad de Alzheimer/genética , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Adulto JovenRESUMEN
AIM: to determine electrophysiological markers of middle cerebral artery blood flow velocity (BFV). PATIENTS AND METHODS: transcranial Doppler registration of middle cerebral artery BFV and direct current (DC) potentials recording from surface of head were performed in 30 healthy volunteers. Analysis of correlation between the BFV and DC potentials was used. RESULTS: significant correlation between BFV and DC potential characteristics was observed. The highest correlation was found between BFV in middle cerebral artery and the difference of DC potentials between central and temporal areas of head (r = 0,55; p = 0,003). These areas coincide with the location of middle cerebral artery and the correlation observed may be connected with streaming potential generated by the blood flow in middle cerebral artery. If electrode placement did not coincide with blood current, DC potentials and BFV were not correlated. CONCLUSIONS: it is assumed that electrical field created BFV in middle cerebral artery may contribute to the generation of DC potentials registered from the head.
Asunto(s)
Circulación Cerebrovascular/fisiología , Fenómenos Electrofisiológicos/fisiología , Arteria Cerebral Media/fisiología , Flujo Sanguíneo Regional/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Arteria Cerebral Media/diagnóstico por imagen , Valores de Referencia , Reproducibilidad de los Resultados , Ultrasonografía Doppler Transcraneal/métodos , Adulto JovenRESUMEN
In patients with discirculatory encephalopathy the influence of verbal fluency test on the characteristics of cerebral perfusion, DC-potentials of the brain, as well as on blood pressure and heart rate was investigated. Two patterns of responses to the verbal fluency test were observed. The first one is the process of generalized activation, manifested by the reduction of the TTP (time to peak) parameters of brain perfusion, the rise of the DC-potentials in all areas of brain and the modulation of blood pressure and heart rate. The second process, directly connected with cognitive processing, was manifested by the shifts of local characteristics of brain perfusion and DC-potentials in the frontal, temporal and central cortex, especially in the left hemisphere. Correlations were found between the characteristics of cerebral perfusion and DC-potentials on the one hand and the number of words during the verbal fluency test performance on the other hand.
Asunto(s)
Encefalopatías/fisiopatología , Mapeo Encefálico/métodos , Encéfalo/fisiopatología , Cognición/fisiología , Potenciales Evocados/fisiología , Imagen de Perfusión/métodos , Conducta Verbal/fisiología , Encefalopatías/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Análisis y Desempeño de TareasRESUMEN
Stroke and traumatic brain injury (TBI) are disabling diseases, which determine the medical and social relevance of the rehabilitation. Age is one of the important risk factor and course factors of stroke. The aim of this research was to study features of the restoration of cognitive function and brain activity in patients undergoing ischemic stroke and TBI. 72 persons were examined (43 males, 29 females; mean age 37.51 +/- 42.97 years). Brain DC potentials were recorded in all patients before and after rehabilitation treatment. Age factor plays an important role in the process of cerebral recovering after brain injury. In patients before 40 years but not after 40 years the rehabilitation was connected with increasing of right hemisphere activity. In patients older 40 years the restoration of cerebral functions was connected with activity of left brain hemisphere.
Asunto(s)
Envejecimiento , Traumatismos Craneocerebrales/fisiopatología , Traumatismos Craneocerebrales/rehabilitación , Potenciales Evocados/fisiología , Infarto de la Arteria Cerebral Media/fisiopatología , Infarto de la Arteria Cerebral Media/rehabilitación , Envejecimiento/psicología , Análisis de Varianza , Cognición/fisiología , Traumatismos Craneocerebrales/psicología , Femenino , Humanos , Infarto de la Arteria Cerebral Media/psicología , Masculino , Pruebas NeuropsicológicasRESUMEN
Associated changes in the characteristics of local cerebral blood flow (CBF) and slow brain electrical activity were studied in 40 patients with dyscirculatory encephalopathy. CBF and CBV (cerebral blood volume) values for the frontal and temporal cortex and basal ganglia positively correlated with the constant potential values in the central lead influenced by the blood flow rate in the upper sagittal sinus.
Asunto(s)
Tiempo de Circulación Sanguínea/normas , Circulación Cerebrovascular , Trastornos Cerebrovasculares , Electroencefalografía/normas , Monitoreo Fisiológico , Ganglios Basales/fisiopatología , Trastornos Cerebrovasculares/diagnóstico , Trastornos Cerebrovasculares/fisiopatología , Femenino , Lóbulo Frontal/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/normas , Lóbulo Temporal/fisiopatología , Tomografía Computarizada de EmisiónRESUMEN
Patients with dyscirculatory encephalopathy (DE) were examined to elucidate interhemisphere relationships by recording brain constant potential (CP) and perfusion CT. Electrophysiological characteristics were shown to relate to local brain blood flow. Dispersion of intrehemisphere CP level in DE patients proved more pronounced than in healthy subjects. Interhemisphere CP difference in temporal region significantly (p < 0.001) correlated with the time needed to reach maximum concentration of contrast agent in the frontal and temporal cortex, basal ganglia, and thalamus. Left temporal CP level positively correlated with contrast agent concentration in the above brain structures of both hemispheres and negatively with that in the right hemisphere. It is concluded that intertemporal relationships may influence vegetative nervous system that in turn changes cardiovascular function.
Asunto(s)
Encéfalo/irrigación sanguínea , Trastornos Cerebrovasculares/fisiopatología , Lateralidad Funcional , Encéfalo/fisiopatología , Circulación Cerebrovascular , Trastornos Cerebrovasculares/diagnóstico por imagen , Femenino , Humanos , Masculino , Potenciales de la Membrana , Persona de Mediana Edad , Tomografía Computarizada por Rayos XAsunto(s)
Potenciales de Acción/fisiología , Encéfalo/fisiología , Metabolismo Energético/fisiología , Hipertiroidismo/fisiopatología , Hipotiroidismo/fisiopatología , Sistemas Neurosecretores/fisiología , Adulto , Electrodos , Humanos , Hipertiroidismo/sangre , Hipertiroidismo/metabolismo , Hipotiroidismo/sangre , Hipotiroidismo/metabolismo , Sistemas Neurosecretores/metabolismo , Hormonas Tiroideas/sangre , Adulto JovenRESUMEN
The dynamics of direct current potentials of the brain was studied in 10-11-year-old children during sustained attention to successive presentation of series of Shulte tables. Children were examined twice: before and after the series of training to fast reading. A gradual increase in the level of direct current potentials during sustained attention was observed. The increase was more pronounced in children with excessive than in children with moderate reactions to the loading. After the series of training to fast reading, the increase in the level of direct current potentials was reduced in both groups. This aftertraining neurophysiological phenomenon was combined with a transformation of psychophysiological characteristics: a decrease in the time of viewing of Shulte tables and increase in the speed of reading. It is suggested that the shifts of direct current potentials reflects the dynamics of intensity of the cerebral energy metabolism.
Asunto(s)
Atención/fisiología , Encéfalo/fisiología , Potenciales Evocados/fisiología , Lectura , Niño , Electroencefalografía , Femenino , Humanos , MasculinoRESUMEN
The application of DC-potential method for estimation of the rate of human brain energy metabolism opens new vistas for the development of theoretical and applied aspects of neurophysiology. Theoretically, the close connection of information and energy processes of the brain is essential for gaining an insight into the brain energy-formation unit. In applied physiology, estimation of brain energy metabolism by the DC potential method is useful for studying the relationship of brain energy and memory processes during learning, for estimating the training in sportsmen, for predicting longevity in the elderly. The method reveals stress-induced changes in interhemispheric relationships. In medicine the method may be used to study the pathogenesis of primarily the diseases associated with impaired cerebral circulation and cerebral atrophic processes. Moreover, of particular diagnostic and prognostic value are these methods for drug addicts, as well as for monitoring suggestive therapeutical effects in the treatment of neuroses.
Asunto(s)
Encéfalo/metabolismo , Encéfalo/fisiología , Electrofisiología , Metabolismo Energético/fisiología , Adaptación Fisiológica , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/fisiopatología , Análisis de Varianza , Barrera Hematoencefálica/fisiología , Encéfalo/fisiopatología , Niño , Diagnóstico Diferencial , Femenino , Humanos , Aprendizaje/fisiología , Peroxidación de Lípido , Masculino , Potenciales de la Membrana/fisiología , Persona de Mediana Edad , Pronóstico , Factores Sexuales , Deportes/fisiología , Estrés Psicológico/diagnóstico , Estrés Psicológico/inmunología , Estrés Psicológico/metabolismo , Estrés Psicológico/fisiopatología , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/fisiopatología , Tomografía Computarizada de EmisiónRESUMEN
The pronounced benzodiazepine (antiphobic) modulation of the amplitude-temporal parameters of different components of the thalamocortical responses (TCR) of the sensorimotor cortex is observed in rabbits in their early postnatal ontogeny. This modulation is of a dose-dependent character and is registered not after the injection of tazepam in a concentration of the "therapeutic tranquilizing window" but also in the psychotoxic plasma range. A gradual increase in blood tazepam concentration in a young rabbit pup is accompanied by the wave-like and differential decrease in the amplitude of the second and third positive (P2 and P3) and third negative (N3) TCR components, while the second negative (N2) and fourth positive (P4) components tend to a wave-like increase. The dose-dependent dynamics of tazepam modulation of the P2, P3, and N3 latencies is characterized by a wave-like and differential increase. The latency of P4 decreases slightly and that of the N2 increases with a low degree of significance. The selective dynamics of benzodiazepine modulation appears to be related with peculiarities of the electrogenesis of each of the components. The dose-dependent modulation of the level of cortical DC potential is of the same character as the respective amplitude changes in P2, P3, and N3, but its fluctiatuons are more pronounced.
Asunto(s)
Ansiolíticos/farmacología , Corteza Cerebral/fisiología , Corteza Motora/fisiología , Oxazepam/farmacología , Corteza Somatosensorial/fisiología , Tálamo/fisiología , Animales , Animales Recién Nacidos , Corteza Cerebral/crecimiento & desarrollo , Relación Dosis-Respuesta a Droga , Ojo/crecimiento & desarrollo , Masculino , Potenciales de la Membrana , Corteza Motora/crecimiento & desarrollo , Conejos , Tiempo de Reacción , Corteza Somatosensorial/crecimiento & desarrollo , Tálamo/crecimiento & desarrolloRESUMEN
The dynamics of the level of direct current potentials and the content of lipid hydroperoxides, conjugated dienes, Schiff bases of phospholipids and lipofuscin in the brain of rats during ontogenesis was studied. It is shown that changes in neurophysiological and biochemical characteristics have an M-shaped character. The synchronization of age-dependent changes in the content of lipid peroxidation products and the dynamics of direct current potentials was revealed.
Asunto(s)
Envejecimiento/fisiología , Encéfalo/fisiología , Peroxidación de Lípido , Potenciales de la Membrana , Envejecimiento/metabolismo , Animales , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Peróxidos Lipídicos/metabolismo , Lipofuscina/metabolismo , Fosfolípidos/metabolismo , Ratas , Bases de SchiffRESUMEN
The functional interhemispheric asymmetry of brain in patients with systemic rheumatic diseases was estimated by measuring brain direct current potentials. It is shown that different types of functional interhemispheric asymmetry correspond to different stages of systemic rheumatic diseases. At early stages, the left hemisphere asymmetry dominates, at expressed stages, the right hemisphere asymmetry is prevalent, and the terminal stage is characterized by the loss of functional interhemispheric asymmetry.
Asunto(s)
Encéfalo/patología , Enfermedades Reumáticas/patología , Encéfalo/fisiopatología , Femenino , Lateralidad Funcional , Humanos , Masculino , Potenciales de la Membrana , Enfermedades Reumáticas/fisiopatologíaRESUMEN
We studied the slow electrical activity of the brain in people subjected to irradiation as a result of the Chernobyl accident and in healthy donors. The mean constant potential, which is an index of energy metabolism in different regions of the cerebral cortex, is reliably lower in eliminators, as compared to the donors, thus suggesting a postradiation energy deficiency of the brain. The structure of correlations between the constant potential indices is different: the number of significant correlations in the group of eliminators is lower by 30% than in the group of donors, thus suggesting disturbed intercentral relations in the CNS under the conditions of postradiation energy deficiency of the brain.
Asunto(s)
Encéfalo/efectos de la radiación , Centrales Eléctricas , Liberación de Radiactividad Peligrosa , Encéfalo/fisiología , Electrodos , Electroencefalografía/instrumentación , Electroencefalografía/métodos , Electroencefalografía/efectos de la radiación , Electroencefalografía/estadística & datos numéricos , Metabolismo Energético/fisiología , Metabolismo Energético/efectos de la radiación , Humanos , Masculino , Persona de Mediana Edad , UcraniaRESUMEN
The data obtained upon examination of patients with systemic rheumatic diseases were analyzed by the methods of multiple regression and step-by-step discriminant analysis. Is was shown that the activity of autoimmune process correlates with the parameters of distribution of constant potential level in the brain of each patient, irrespective of diagnosis. The scatter of potential values was the most important predictor of activity. An increase in the activity of the autoimmune process correlated with a decrease in the scatter of potential values at recording points; the cerebral cortex became equipotential.
Asunto(s)
Autoinmunidad , Encéfalo/fisiopatología , Enfermedades Reumáticas/inmunología , Potenciales de Acción , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Reumáticas/fisiopatologíaRESUMEN
Neuroimmune interactions in systemic rheumatic diseases were studied. The state of the central nervous system was assessed from the parameters of constant brain potentials, and the state of the immune system, from a complex of immunobiochemical parameters. The highest multiple correlation coefficients were revealed between the immunobiochemical parameters and the parameters of the constant brain potential, which characterize linear and standard deviations of potentials in temporal zones from potentials at other points of recording. The results are discussed in terms of structural and functional integration of the immune and nervous systems.
Asunto(s)
Autoinmunidad , Encéfalo/fisiopatología , Enfermedades Reumáticas/inmunología , Potenciales de Acción , Adolescente , Adulto , Biomarcadores , Femenino , Humanos , Masculino , Enfermedades Reumáticas/fisiopatologíaRESUMEN
A correlation between the serum levels of the stress hormone cortisole, neurophysiological parameters, and age was examined in 23 elderly healthy examinees (whose mean age was 65.7 +/- 2.1 years). The latency of the components of visual evoked potentials (VEP) was found to progressively increase with age. The individuals having high cortisole levels showed an increase in the latency of late VEP components associated with accelerated ageing and/or with the degenerative changes in the brain limbicoreticulocortical pathways. The DC potential level (DCPL) reflecting the intensity of brain energy expenditures correlated with the content of cortisole. Increased DCPL and longer latency of late VEP components were interrelated. It is suggested that high cortisole level produces a neurotoxic action and promotes accelerated ageing of brain regions having glucocorticoid receptors. Imbalance between the significant intensification of catabolic processes, the rise of energy expenditures and the limited increase in anabolism in elderly age is a course of this process.
Asunto(s)
Envejecimiento/fisiología , Encéfalo/fisiología , Hidrocortisona/sangre , Anciano , Electroencefalografía , Metabolismo Energético/fisiología , Potenciales Evocados Visuales , Femenino , Humanos , Masculino , Neurofisiología , Receptores de Esteroides/metabolismo , Valores de ReferenciaRESUMEN
Visual evoked potentials versus flash (VEP) and brain DC-potentials were studied in the first-order relatives of patients (mean age 42.6 +/- 1.6 years) with Alzheimer's disease (AD) and probands (mean age 60.9 +/- 0.9 years) and age-matched healthy controls for the relatives and probands. In the relatives of AD patients, the latencies of N2, P3, N3 components were found to be delayed as compared with the controls. There was a delay in the latencies of the same components in the patients and their relatives, but it was smaller in the relatives of AD patients. The brain DC-potentials were higher in the relatives of AD patients than in the controls. Neurophysiological changes in the relatives of AD patients may be considered to be signs of latent neurodegeneration in the limbicoreticulocortical pathways, which may be associated with the excitotoxic processes and abnormal hyperactivity in the limbicoreticulocortical structures.
Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Encéfalo/fisiopatología , Adulto , Enfermedad de Alzheimer/genética , Electroencefalografía , Potenciales Evocados , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Factores de RiesgoRESUMEN
The dynamics of functional interhemispherical asymmetry in the ontogenesis of rats, males and females separately, was studied. The asymmetry was determined by the neurophysiological criterion, the interhemispherical gradient of the distribution of direct current potential of the brain. The sexual dimorphism upon age-related changes in the interhemispherical asymmetry was shown. It is assumed that this asymmetry is involved in the dynamics of neuroendocrine interactions determined by sex.
Asunto(s)
Encéfalo/fisiología , Lateralidad Funcional , Ratas/crecimiento & desarrollo , Caracteres Sexuales , Animales , Femenino , Masculino , Potenciales de la MembranaRESUMEN
The systemic organization of hemispherical asymmetry at the behavioral, neurophysiological, and biochemical levels was studied. An interconnection and hierarchic coordination of the parameters of different levels were revealed, which are confirmed by multiple correlations between them. An interrelation between the processes of peroxidation of brain membrane lipids, the level of direct current potential, and the behavior of animals was shown. A significant difference in correlations between right-hander and left-hander animals was found.
Asunto(s)
Encéfalo/fisiología , Lateralidad Funcional , Animales , Conducta Animal , Encéfalo/metabolismo , Peroxidación de Lípido , Lípidos de la Membrana/metabolismo , Potenciales de la Membrana , RatasRESUMEN
Visual-evoked potentials (VEP) to a flash were studied in the first-order relatives of patients with Alzheimer's disease (AD) (mean age 38.2 +/- 2.6 years) in comparison with the patients (mean age 61.9 +/- 1.4 years) and age-matched normal controls. It was found that in the relatives of AD patients the latencies of N2, P3, N3 components were delayed compared with the age-matched normal controls. The delay in the latencies of the patients and their relatives concerned the same components but was smaller in the relatives of AD patients. The amplitude of the P2, N2 components was increased in the latter. The neurophysiological alteration in AD patients' relatives may be considered as signs of a latent neurodegeneration in limbico-reticulo-cortical pathways, which may be connected to the pathological hyperactivity of limbico-reticulo-cortical structures.