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At least 235 records · Page 13Linked to original sources
PubMedDate not supplied

The unilateral spatial neglect phenomenon in patients with arteriovenous malformations of deep brain structures.

Clinical-neuropsychological investigations were performed in 187 patients with arteriovenous malformations (AVM) of deep brain structures; 28 had AVM of the caudate nucleus, 35 of the thalamus, 45 of the cingulate gyrus, 43 of the hippocampus, and 36 of the corpus callosum. A total of 47 patients displayed neglect phenomena of different modalities, while unfixed neglect was demonstrated in 40 cases using special tests. The vast majority of patients showed neglect of left-sided space and the left side of the body, while only three patients showed right-sided neglect. These three patients had signs of left-handedness. In the development of neglect in all patients was associated with post-hemorrhagic or post-operative damage to the white matter (the projections of sensory bundles of the parietal and occipital lobes, the periventricular white matter) or the thalamus and corpus callosum. In hemispheric lesions, neglect developed on the background of the corresponding derangements (hemihypesthesia hemianopsia) and were of the same modality. In cases of damage to the corpus callosum, neglect could develop without accompanying sensory disturbances or the phenomenon could occur on different sides (in cases of simultaneous left hemisphere damage). This supports the independent nature of the neglect phenomenon.

Brain↗
PubMed1987

[BB creatine phosphokinase activity and content of the brain structures in senile dementia and Alzheimer's diseases].

The creatine kinase (CPK) activity and content were determined in certain brain structures of patients with Alzheimer's disease and senile dementia and in the control group. The findings demonstrated the 5-10-fold decrease of CPK activity in the majority of the investigated brain areas and a 30-fold decrease in the occipital gyrus. The activity decrease did not depend on postmortal interval, sex and age. The content of CPK was increased in the same structures (130% of the control level). So an elevation in CPK values appears to compensate for the fall in CPK activity. Such phenomena can lead to different disturbances in energy metabolism of the brain in mental patients.

Aged↗
PubMedDate not supplied

[Effects of afobazole on the BDNF content in brain structures of inbred mice with different phenotypes of emotional stress reaction].

Changes in the BDNF content in brain structures--hippocampus, hypothalamus, striatum, and frontal cortex--were determined in mice of different emotional-stress reaction phenotypes, which were subjected to emotional stress and treated by the selective anxiolytic afobazole. The changes were different in BALB/c and C57BL/6 mice. Afobazole exhibited a significant protector action against a decrease in the brain BDNF level caused by emotional stress in BALB/c mice.

Animals↗
PubMed2005

The relationship between eye movement and brain structural abnormalities in patients with schizophrenia and their unaffected relatives.

Schizophrenia is associated with subtle eye movement and brain structural abnormalities, but the extent to which these abnormalities occur in the same individuals is unclear. The relationship between quantitative measures of eye movement task performance (smooth pursuit and antisaccade) and MRI volumetric measurements (whole brain volume, prefrontal region, lateral ventricles, third ventricle, hippocampus, and cerebellum) was assessed in 70 patients with schizophrenia or schizoaffective disorder, 105 of their unaffected first-degree relatives and 68 controls. There was a lack of correlation between eye movement and morphometric abnormalities suggesting largely separable neurobiological pathways underlying the morphological and the eye movement deviations that have previously been identified in these patients. However, in the total sample, smaller prefrontal lobe volume was significantly associated with longer latency of correct antisaccades (partial correlation r=-0.22, p=0.01) in line with previous studies demonstrating the importance of frontal lobe structures in performance of the antisaccade task. Also larger third ventricular volume was associated with larger mean amplitude of intrusive saccades during smooth pursuit (r=0.28, p=0.01). There were no significant between-group differences in the relationship between measures of eye movement and morphometry.

Adolescent↗
PubMedDate not supplied

[Changes in the level of oxygen tension in different brain structures of rats in positive and negative emotional states].

Changes of oxygen tension (pO2) level in various brain structures were studied in rats in positive and negative emotional states. It is established that pO2 level changes depend on the character of behavioural reactions: "active" type of behaviour (emotionally positive orienting-investigatory, actively defensive) is accompanied by pO2 level increase, and "passive" type of behaviour ("freezing" reaction)--by a decrease of pO2 level. Changes of oxidative brain metabolism observed at "active" and "passive" types of behaviour indicate, respectively, adaptive and nonadaptive character of these behavioural reactions.

Adaptation, Physiological↗
PubMedDate not supplied

[The effect of diazepam on the free fatty acid content in the brain structures of rats with an experimental neurosis].

The composition of free fatty acids of lipids in different rat brain structures (the cortex, hippocampus, striatum and midbrain) in neurosis was studied by the gas chromatographic analysis. The difference in their spectra was established. A pronounced increase of arachidonic acid content in the cortex (by 120%, p less than 0.01) and a statistically significant elevation of linolic acid level in all studied structures were noted. The levels of pentadecanoic and myristic acids were also changed. In neurosis diazepam (0.5 mg/kg, intraperitoneally, 40 minutes before the investigation) produced a decrease in the brain cortex of levels of arachidonic, oleic and myristic acids. In the hippocampus the contents of oleic and myristic acids increased. Less pronounced changes were found in the striatum and midbrain.

Animals↗
PubMed1975

[Change in monoamine content and monoamine oxidase activity in brain structures during experimental allergic encephalomyelitis].

The serotonin, noradrenaline, adrenaline concentration in the blood, cerebrospinal fluid and some brain structures, and tissue monoaminoxidase activity (MAO) were investigated in dogs during experimental allergic encephalomyelitis. During the perparalytic period there was a tendency to reduction of the serotonin concentration and to the elevation of the catecholamine content. The stage of clinical manifestation of encephalomyelitis was accompanied by reduction of the serotonin level in the white matter of the cerebral hemispheres, and by genralized inhibition of the adrenergic structures. In this case the MAO activity displayed no significant change; this permitted to consider the disturbance of the monoamine synthesis as a result of immune aggression, as a possible cause of inhibition of the monoaminergic system.

Animals↗
PubMed2004

Biochemical and structural brain alterations in female mice with cerebral pyruvate dehydrogenase deficiency.

Pyruvate dehydrogenase complex (PDC) deficiency is an inborn metabolic disorder associated with a variety of neurologic abnormalities. This report describes the development and initial characterization of a novel murine model system in which PDC deficiency has been introduced specifically into the developing nervous system. The absence of liveborn male and a roughly 50% reduction in female offspring following induction of the X-linked mutation indicate that extensive deficiency of PDC in the nervous system leads to pre-natal lethality. Brain tissue from surviving females at post-natal days 15 and 35 was shown to have approximately 75% of wild-type PDC activity, suggesting that a threshold of enzyme activity exists for post-natal survival. Detailed histological analyses of brain tissue revealed structural defects such as disordered neuronal cytoarchitecture and neuropil fibers in grey matter, and reduced size of bundles and disorganization of fibers in white matter. Many of the histologic abnormalities resemble those found in human female patients who carry mutations in the X-linked ortholog. These findings demonstrate a requirement for PDC activity within the nervous system for survival in utero and suggest that impaired pyruvate metabolism in the developing brain can affect neuronal migration, axonal growth and cell-cell interactions.

Acetates↗
PubMed1994

Effect of in utero radiation dose fractionation on rat postnatal development, behavior and brain structure: 3-hour interval.

Effect of In Utero Radiation Dose Fractionation on Rat Postnatal Development, Behavior and Brain Structure: 3-Hour Interval. Neurotoxicology 15(1): 183-190, 1994. We have previously shown that exposure of the rat fetus to ionizing radiation produces dose-dependent (0.25-1.25 Gy) changes in postnatal growth and behavior, and decreases in cerebral cortex thickness. Pregnant rats were exposed to single doses of 0.5 or 1.0 Gy, or to two doses of 0.5 Gy (separated by a 3 h interval) on gestational day 15. Pups were weighed and subjected to behavioral tests (righting reflex; reflex suspension; negative geotaxis; continuous corridor; and length, width, and sine of gait) over postnatal days 7-28. The rats were then sacrificed and brains removed for histology. The fractionated doses produced responses that were generally intermediate between those produced by the single doses and which, by interpolation, could be expressed as equivalent to a single dose between 0.5 and 1.0 Gy. Overall, exposure of the fetal rat to two doses of 0.5 Gy separated by 3 h produced effects equivalent to a single dose of 0.85 Gy. We conclude that fractionation of radiation dose results in less damage to the developing rat cerebral cortex, as measured by postnatal growth, behavioral tests, and morphological assessment.

Animals↗
PubMed2002

Development of cortical and subcortical brain structures in childhood and adolescence: a structural MRI study.

The purpose of the present study was to describe in greater anatomical detail the changes in brain structure that occur during maturation between childhood and adolescence. High-resolution MRI, tissue classification, and anatomical segmentation of cortical and subcortical regions were used in a sample of 35 normally developing children and adolescents between 7 and 16 years of age (mean age 11 years; 20 males, 15 females). Each cortical and subcortical measure was examined for age and sex effects on raw volumes and on the measures as proportions of total supratentorial cranial volume. Results indicate age-related increases in total supratentorial cranial volume and raw and proportional increases in total cerebral white matter. Gray-matter volume reductions were only observed once variance in total brain size was proportionally controlled. The change in total cerebral white-matter proportion was significantly greater than the change in total cerebral gray-matter proportion over this age range, suggesting that the relative gray-matter reduction is probably due to significant increases in white matter. Total raw cerebral CSF volume increases were also observed. Within the cerebrum, regional patterns varied depending on the tissue (or CSF) assessed. Only frontal and parietal cortices showed changes in gray matter, white matter, and CSF measures. Once the approximately 7% larger brain volume in males was controlled, only mesial temporal cortex, caudate, thalamus, and basomesial diencephalic structures showed sex effects with the females having greater relative volumes in these regions than the males. Overall, these results are consistent with earlier reports and describe in greater detail the regional pattern of age-related differences in gray and white matter in normally developing children and adolescents.

Adolescent↗
PubMed2003

Comparative analysis of LPO products in brain structures of Wistar and OXYS rats of different age.

We analyzed the content of LPO products in various brain areas of Wistar and OXYS rats characterized by early appearance of changes in the emotional and cognitive spheres typical of aging. Marked differences between brain regions were found in both strains, but were more pronounced in Wistar rats. The content of LPO products in OXYS rats was higher in the midbrain, hippocampus, nuclei accumbens and striatum at the age of 2 months and in the midbrain, hippocampus, and nuclei accumbens at the age of 18 months. At the age of 18 months the content of LPO products was higher than at the age of 2 months in the amygdala and nuclei abbumbens of Wistar rats and in the nuclei accumbens and midbrain of OXYS rats, while in the hippocampus and hypothalamus of both rat strains and in the striatum of OXYS rats the content of LPO products at the age of 18 months was lower than at the age of 2 months. These results indicate that deviations in cognitive and emotional spheres of OXYS rats develop against the background of LPO activation in brain structures critical for training and memory, which indicates their relationship with oxidative stress.

Age Factors↗
PubMed1976

[An analysis of EEG rhythm changes following micropolarization of several brain structures].

With the aid of the EEG special statistical analysis, micropolarization of the temporal cortex of hypothalamus was shown to entail abrupt alterations of the theta-, alpha-, and beta-rhythms in the temporal and motor cortex, hypothalamus, and the midbrain RF. The changes of the biorhythms (their correlation, thresholds of occurring, connection of the local and distant shifts) are regarded as reflecting some fine regulation of the structures' functional condition as well as mutual influences of the cortex and the deep brain structures which tell on modulation of mnemic processes.

Animals↗
PubMed1999

Alterations in brain structure and function associated with post-traumatic stress disorder.

Neuroimaging studies in post-traumatic stress disorder (PTSD) have revealed changes in brain structure and function that may underlie the symptoms of PTSD. Two brain areas that have been consistently implicated in PTSD include the hippocampus and prefrontal cortex. Several studies showed that PTSD is associated with reduction in volume of the hippocampus, a brain area involved in learning and memory, as measured with magnetic resonance imaging (MRI). Positron emission tomography (PET) studies showed dysfunction of medial and orbital prefrontal cortex during PTSD symptom provocation and in response to traumatic reminders. Decreased benzodiazepine receptor binding was found in the medial prefrontal cortex as measured with neuroimaging in PTSD. The hippocampus and medial prefrontal cortex play important roles in memory and emotional regulation, and dysfunction in these areas may underlie memory deficits and pathological emotions in PTSD.

Brain↗
PubMedDate not supplied

The action of agonists and an antagonist of GABA on the frequency composition of the electrical activity of various brain structures of rats.

The frequency composition of the electrograms (EG) of the visual area of the cortex and deep brain structures (putamen, dorsal hippocampus, medial portion of the mid-hypothalamus) were investigated in chronic experiments in 36 awake rats under the conditions of the separate and combined introduction of GABA, its agonists (muscimol, baclofen), and an antagonist (bicuculline) into the lateral ventricle of the brain. The principal effects were manifested primarily in the form of a decrease in the power of the oscillations in the 7-16 Hz region of the range (1-25 Hz) of EG frequencies analyzed. Even though these changes were unidirectional following the administration of the agonists, they nevertheless differed with respect to the degree of expressivity in the different structures. Bicuculline, injected against the background of the action of muscimol and baclofen, attenuated the effects induced by them. The possible mechanisms of the phenomena discovered are discussed.

Animals↗
PubMedDate not supplied

Structural brain abnormalities in juvenile myoclonic epilepsy patients: volumetry and voxel-based morphometry.

OBJECTIVE: We aimed to find structural brain abnormalities in juvenile myoclonic epilepsy (JME) patients. MATERIALS AND METHODS: The volumes of the cerebrum, hippocampus and frontal lobe and the area of the corpus callosum's subdivisions were all semiautomatically measured, and then optimized voxel-based morphometry (VBM) was performed in 19 JME patients and 19 age/gender matched normal controls. RESULTS: The rostrum and rostral body of the corpus callosum and the left hippocampus were significantly smaller than those of the normal controls, whereas the volume of the JME's left frontal lobe was significantly larger than that of the controls. The area of the rostral body had a significant positive correlation with the age of seizure onset (r = 0.56, p = 0.012), and the volume of the right frontal lobe had a significant negative correlation with the duration of disease (r = -0.51, p = 0.025). On the VBM, the gray matter concentration of the prefrontal lobe (bilateral gyri rectus, anterior orbital gyri, left anterior middle frontal gyrus and right anterior superior frontal gyrus) was decreased in the JME group (corrected p < 0.05). CONCLUSION: The JME patients showed complex structural abnormalities in the corpus callosum, frontal lobe and hippocampus, and also a decreased gray matter concentration of the prefrontal region, which all suggests there is an abnormal neural network in the JME brain.

Adult↗
PubMedDate not supplied

[The effect of stereotaxic injuries on the medial temporal brain structures on memorization of successively or simultaneously presented material].

Effect of stereotaxic injuries to the medial temporal brain structures on memorization of material presented successively or simultaneously was studied. The study aimed at testing whether stereotaxic damage to the hippocampus and amygdala results in a memory deficit and whether functions subserved by those structures depend on type and organization of the memorized material. The results indicate that even small damage to the medial temporal lobe structures may result in a deficit in memorization ability. The greatest impairment was observed for successive presentation of nonverbal stimuli.

Adult↗
PubMedDate not supplied

Effects of acute hypoxia on the EEG and impulse activity of the neurons of various brain structures in rats.

The EEG and impulse activity of the neurons of the cerebral cortex and other structures of the brain were studied in the dynamics of hypoxic influence. In the initial phase of hypoxia (2000-6000 m), activation of the EEG and impulse discharge of neurons set in; in this case EEG activation arose earlier and was more pronounced. In the second phase of hypoxia (7500-10,000 m), the EEG changed in the direction of a reorganization of the frequency spectrum from one rhythm to another - from fast to slow activity of the type of delta waves. At this time the impulse activity was gradually suppressed, and the cortical neurons exhibited higher sensitivity to hypoxia and were inhibited earlier than the cells of the hypothalamus and medulla oblongata.

Altitude↗