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At least 343 records · Page 19Linked to original sources
PubMed1999

Brain structure and neurocognitive and behavioural function in adolescents who were born very preterm.

BACKGROUND: Infants born very preterm (<33 weeks) are at increased risk of neurocognitive deficits. Their neurodevelopmental outcome up to age 8 years can be predicted by neonatal ultrasonography, but little is known of their later function. We investigated the effect of very preterm birth on brain structure and neurocognitive and behavioural functioning in adolescence. METHODS: A cohort of 105 infants born before 33 weeks of gestation in 1979-80 had ultrasonographic scans at University College Hospital, London, and were prospectively examined at 1, 4, and 8 years. At age 14-15 years, 72 of those who remained in UK (cases) and 21 age-matched full-term controls underwent brain magnetic resonance imaging (MRI), as well as neurological, cognitive, and behavioural assessment. MRI images were assessed by two neuroradiologists unaware of ultrasonographic findings or case or control status. FINDINGS: Of the 72 cases, 40 had unequivocally abnormal MRI and 15 had equivocal scans. Of the 21 controls, one had abnormal and five equivocal MRI. Abnormalities of ventricles, corpus callosum, and white matter were especially common in cases. More brain lesions were identified by MRI than by neonatal ultrasonography. The cases had significantly more reading, adjustment, and neurological impairments than controls, but their behaviour was significantly related to MRI abnormality. INTERPRETATION: Individuals born very preterm show an excess of neurocognitive and behavioural problems in adolescence, and more than half have abnormal MRI brain scans.

Adolescent↗
PubMed1986

[Metabolism and bioelectric activity of individual brain structures in response to the neuropeptide taftsine].

The effect of taftsine (T) tetrapeptide was studied on the systemic and subcellular levels. T was found to exert a specific effect on the activities of acetylcholinesterase and MAO molecular forms. The use of T altered the evoked potentials to a signal light stimulus in the cortical and subcortical brain structures. Rearrangements of the membranous proteins (by the content of sulfhydryl groups) detected in subfractions of synaptosomes were most expressed in the visual zone of the cortex. Thus, T exerts a modifying influence on various aspects of mediator metabolism and also on the perception of biologically important sensory stimuli.

Acetylcholinesterase↗
PubMed2004

Mapping brain structure and personality in late adulthood.

Cerebral gray matter (GM) volume decreases in normal aging with a parallel increase in intracranial cerebrospinal fluid (CSF) volume. There is considerable interindividual variation in these changes, and the consequences of age-related GM shrinkage and CSF expansion are unclear. The present study examined whether late adulthood brain structural differences are related to differences in temperament and character. Personality structures of 42 healthy aged adults (mean age 60 years) were examined together with global and regional GM, CSF, and white matter (WM) volumes calculated from structural magnetic resonance images using voxel-based morphometry (VBM). A positive relationship was seen between GM volume at the border of the temporal, parietal, and frontal cortices, and self-transcendence, a character personality trait that reflects mature creativity and spiritualism. The relationship remained significant after a conservative correction for multiple comparisons and it was seen both using uncorrected raw values and after a correction for the effects of age and sex. The results suggest that high self-transcendence, which has adaptive advantages in the later part of life, is associated with relatively greater temporal cortical GM volumes.

Adult↗
PubMed1994

Developmental brain abnormalities in the offspring of schizophrenic mothers. II. Structural brain characteristics of schizophrenia and schizotypal personality disorder.

BACKGROUND: We examined differences in ventricular and sulcal cerebrospinal fluid-to-brain ratios as a function of lifetime psychiatric diagnosis in the offspring of schizophrenic mothers (high-risk sample) and in the offspring of normal parents (low-risk sample). METHODS: We used a cohort analytic study of 17 high-risk individuals with schizophrenia, 31 high-risk individuals with schizotypal personality disorder, 33 high-risk individuals with nonschizophrenia-spectrum psychiatric disorders, 45 high-risk individuals with no disorders, 31 low-risk individuals with psychiatric disorders of all types, and 46 low-risk individuals with no disorders, evaluated initially in 1962 when they were a mean age of 15 years, and reexamined from 1986 through 1989 with psychiatric interviews and computed tomographic scans of the brain. RESULTS: High-risk individuals with schizophrenia and schizotypal personality disorder evidenced an equivalent degree of cortical sulcal enlargement, and both groups evidenced significantly greater sulcal enlargement than did high-risk individuals with nonschizophrenia-spectrum disorders and no disorders and low-risk individuals with psychiatric disorders and no disorders. High-risk individuals with schizophrenia evidenced significantly greater ventricular enlargement than did high-risk and low-risk subjects with other disorders and no disorders, including those with schizotypal personality disorder. These differences were independent of age, gender, history of substance dependence, and history of organic brain syndromes and head injuries. CONCLUSIONS: Among the offspring of schizophrenic parents, cortical abnormalities are expressed equally across the range of syndromes in the schizophrenia spectrum. Subcortical abnormalities (ie, ventricular enlargement) are more pronounced in the more severe syndrome (ie, schizophrenia).

Adult↗
PubMed1983

[Functional interrelation of the brain structures of the cat during the generation of rhythmic activity. I. The frequency characteristics of the electroencephalogram].

The similarity of frequency parameters of electroencephalograms (EEG) recorded from visual, associative and sensorimotor cortical area, caudate nucleus and several thalamic nuclei have been analysed using the period analysis of EEG and cluster analysis of data obtained to clarify the functional interrelationships between these parts of the brain during generation of rhythmic activity of different types. Functional interrelationships between brain structures in freely moving cats during the states of drowsiness and slow-wave sleep have been shown to differ from "classical" thalamo-cortical pacemaker relations.

Animals↗
PubMed2000

Metabolism of neurotransmitters in cortical and subcortical brain structures in rats with different behavioral characteristics.

Experiments were performed on Wistar rats with high and low locomotor activities. In rats with high locomotor activity, activities of acetylcholine transferase, acetylcholine esterase, and monoamine oxidase A increased in the subcellular fractions of the sensorimotor cortex and arcuate nucleus, while monoamine oxidase B activity decreased compared to those in rats with low locomotor activity. The peculiarities of neurotransmitter systems in brain structures of rats with different behavioral patterns were related to genetic and functional organization of the central nervous system.

Animals↗
PubMed2002

Effects of chronic restraint stress on feeding behavior and on monoamine levels in different brain structures in rats.

Monoaminergic systems are important modulators of the responses to stress. Stress may influence feeding behavior, and the involvement of monoamines in the control of food intake is well recognized. We investigated the effects induced by chronic-restraint stress, 1 h a day, for 40 days, on eating behavior and on monoamines in distinct brain structures. Increased consumption of sweet pellets, and not of peanuts, was observed. Dopamine (DA), serotonin (5-HT), and their metabolites were measured by HPLC-EC. After chronic restraint, the results observed were decreased 5-HT in hippocampus, with increased 5-HIAA/5-HT; decreased 5-HIAA levels in cortex; reduction in DA in hippocampus, and increased levels in amygdala and hypothalamus; HVA increased in cortex, as well as HVA/DA ratio, while DOPAC/DA decreased. HVA decreased in hypothalamus, as well as HVA/DA, and DOPAC/DA and HVA/DA decreased in the amygdala. These results suggest that restraint stress differentially affects the activity of central dopaminergic and serotonergic neurons, and this may be related to the effects observed in eating behavior.

Animals↗
PubMedDate not supplied

[Biogenic amines in the brain structures of rats from genetically diverse strains under stress].

The content was studied of biogenic amines and their metabolites (by the method of high-effective fluid chromatography electrochemical detection) in the reticular formation of the midbrain, locus coeruleus and sensorimotor cortex in the rats of Wistar and August lines, differing in the behaviour in the open field, in conditions of immobilization stress. The dependence was revealed of the biogenic amines level on the animals genotype and individual characteristics. Most probably, the level of biogenic amines metabolism in central brain structures determines the stability of the animals against emotional stress.

Animals↗
PubMed2006

Perinatal choline influences brain structure and function.

Choline is derived not only from the diet, but also from de novo synthesis. It is important for methyl-group metabolism, the formation of membranes, kidney function, and neurotransmission. When deprived of dietary choline, most adult men and postmenopausal women develop signs of organ dysfunction (fatty liver or muscle damage) and have a decreased capacity to convert homocysteine to methionine. Choline is critical during fetal development, when it influences stem cell proliferation and apoptosis, thereby altering brain structure and function (memory is permanently enhanced in rodents exposed to choline during the latter part of gestation).

Brain↗
PubMedDate not supplied

[Functional organization of limbic brain structures during conditioned reflex activity in the dog].

In experiments on 3 dogs it was shown that instrumental defensive conditioned reflex (CR) to electrical stimulation of the hippocampus is generalized within the limbic system (LS). The rate of generalization depended on the place of testing stimuli in LS. Stimulation of the medial parts of LS at the stage of stabilized initial reflex did not produce the generalized CRs, while they appeared distinctly in response to stimulation of the lateral parts of LS. In the process of elaboration of heterogeneous CRs (defensive and alimentary) to electrical stimulation of the hippocampus, generalized conditioned reactions from some brain structures appeared in both situations to the same degree while from other structures--with considerable differences. These data point to a possible participation in the genesis of the generalized CRs both of signal and reinforcing brain mechanisms.

Amygdala↗
PubMed2003

Enhancing action of LSD on neuronal responsiveness to serotonin in a brain structure involved in obsessive-compulsive disorder.

Potent serotonin (5-HT) reuptake inhibitors are the only drugs that consistently exert a therapeutic action in obsessive-compulsive disorder (OCD). Given that some hallucinogens were reported to exert an anti-OCD effect outlasting their psychotomimetic action, possible modifications of neuronal responsiveness to 5-HT by LSD were examined in two rat brain structures: one associated with OCD, the orbitofrontal cortex (OFC), and another linked to depression, the hippocampus. The effects of concurrent microiontophoretic application of LSD and 5-HT were examined on neuronal firing rate in the rat OFC and hippocampus under chloral hydrate anaesthesia. In order to determine whether LSD could also exert a modification of 5-HT neuronal responsiveness upon systemic administration, after a delay when hallucinosis is presumably no longer present, it was given once daily (100 microg/kg i.p.) for 4 d and the experiments were carried out 24 h after the last dose. LSD attenuated the firing activity of OFC neurons, and enhanced the inhibitory effect of 5-HT when concomitantly ejected on the same neurons. In the hippocampus, LSD also decreased firing rate by itself but decreased the inhibitory action of 5-HT. The inhibitory action of 5-HT was significantly greater in the OFC, but smaller in the hippocampus, when examined after subacute systemic administration of LSD. It is postulated that some hallucinogens could have a beneficial action in OCD by enhancing the responsiveness to 5-HT in the OFC, and not necessarily in direct relation to hallucinosis. The latter observation may have theoretical implications for the pharmacotherapy of OCD.

Action Potentials↗
PubMed1993

Effect of in utero irradiation on the postnatal development, behavior, and brain structure of rats: dose fractionation with a 6-h interval.

Based on previous studies showing that exposure of the rat fetus to ionizing radiation produces dose-dependent (0.25-1.25 Gy) changes in postnatal development of behavior and decreases in the thickness of the cerebral cortex, we examined the extent to which dose fractionation would reduce expression of damage. Pregnant rats were exposed to single doses of 0.5 or 1.0 Gy, or to two doses of 0.5 Gy 6 h apart on day 15 of gestation. Offspring were subjected to four behavioral tests on postnatal days 7-28; the rats were then sacrificed and their brains removed and processed for histology. For all end points, the fractionated dose produced an effect that was intermediate between that of the 0.5- and 1.0-Gy doses and which, by interpolation, could be expressed as equivalent to a single dose between 0.5 and 1.0 Gy. The equivalent single dose was not significantly different from the 1.0-Gy dose for negative geotaxis (0.54 Gy), reflex suspension (0.80 Gy), and continuous corridor (0.85 Gy). For sine of the angle of the advance of hind feet (0.58 Gy), width of stride (0.69 Gy), length of stride (0.75 Gy), body weight (0.73 Gy), and cerebral cortex thickness (0.69 Gy), the fractionated dose produced effects significantly different (P < 0.05) from the 1.0-Gy dose. Overall, exposure of fetal rats to two doses of 0.5 Gy separated by 6 h produced effects equivalent to a single dose of 0.70 Gy, as measured by postnatal behavioral tests and morphological assessment of brain structure.

Animals↗
PubMed1999

[Changes in the enzyme activity in the brain structures of August rats under the influence of the delta sleep-inducing peptide against a background of prolonged L-dihydroxyphenylalanine administration].

Quantitative cytochemical methods revealed the decrease of MAO activity (substrate--tryptamine) in the hippocampus of L-dioxytryptamine treated August rats genetically predisposed to emotional stress under the effect of delta sleep inducing peptide (DSIP). Activities of aminopeptidase and glutamate dehydrogenase were decreased in n.accumbens while changes of the activities of these enzymes were not significant in the layers III and V of sensomotor cortex and n.caudatus. In all brain structures Ache and MAO (substrate 5-hydroxytryptamine) activities were not influenced by DSIP.

Animals↗
PubMedDate not supplied

[The role of the emotiogenically negative brain structures in realizing an acid-defensive instrumental motor reaction].

In experiments in dogs it has been found that testing electrical stimulation of the lateral hypothalamus (duration of this stimulation--5-7 s), of the ventromedial hypothalamus and of the substantia grisea centralis of mesencephalon reproduced earlier elaborated acid-defensive instrumental conditioned reflex. This fact takes place due to the activation of the brain structures of negative emotion.

Animals↗
PubMed1994

Laser Doppler flowmetry of focal ischaemia and reperfusion in deep brain structures in rats.

Monitoring cerebral blood flow during focal ischaemia and reperfusion with established techniques such as hydrogen clearance and autoradiography is difficult. Laser Doppler flowmetry is a new technique, it allows one to continuously measure blood flow in small tissue samples. The objective of this study was to compare laser Doppler flowmetry with hydrogen clearance using a new single fiber probe to obtain measurements in deep brain structures and then to show the temporal profile of cerebral blood flow during focal ischaemia and after reperfusion. First, the single fiber laser Doppler method was compared with the hydrogen clearance method in ten Wistar rats. Second, focal cerebral ischaemia was induced in fifteen Wistar rats using a model of middle cerebral artery occlusion based on the intravascular insertion of a nylon suture; reperfusion occurred after withdrawal of the suture. The laser Doppler probe was placed in the lateral caudatoputamen, and local cerebral blood flow was measured continuously before and during occlusion as well as after reperfusion. The relative blood flow values obtained by the laser Doppler method and the hydrogen clearance method showed a good correlation (r = 0.76) and a linear relationship. A rapid decrease in laser Doppler flowmetry to 42 +/- 16% of former baseline values was seen with occlusion of the middle cerebral artery; during occlusion cerebral blood flow remained at this level. Reperfusion resulted in a heterogeneous pattern of cerebral blood flow as laser Doppler flowmetry values ranged from 25% to 134% of baseline values. The effects of middle cerebral artery occlusion and reperfusion on cerebral blood flow can be monitored on-line with laser Doppler flowmetry.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗