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PubMedDate not supplied

[Norepinephrine content in various brain structures and activity of alcohol dehydrogenase and aldehyde dehydrogenase in blood serum of rats with varying predisposition to ethanol consumption].

Noradrenaline content in hypothalamus, midbrain and new cortex as well as the activity of alcohol- and aldehyde dehydrogenase in the blood serum of rats with different alcohol motivation were studied. It is shown that rats, which prefer ethanol, are characterized by the lower content of noradrenaline in hypothalamus, midbrain and new cortex as compared to animals which prefer water. It is found out that alcohol motivation in rats correlates with high activity of blood serum aldehyde dehydrogenase. No reliable relation between ethanol preferring and activity of blood alcohol dehydrogenase was revealed.

Alcohol Dehydrogenase↗

PubMedDate not supplied

[The effect of serotonin antibodies on the behavior of C57Bl/6 mice in an open field and on the level of monoamines in the brain structures].

Mice of C57BL/6 strain were singly injected intraperitoneally with antibodies (AB) to serotonin (5-HT). The "open-field" testing in different periods after the AB injection revealed a depression of behavior within 1.5 h which changed for activation within 1 day and, again, depression within 5 days after the injection. The analysis of neurotransmitter content in the sensorimotor cortex and hypothalamus revealed increased levels of serotonin and, especially, dopamine in the cortex within 1 day. The cortex serotonin level within 5 days was also increased. The possible mechanisms are discussed of neurotropic action of AB to 5-HT.

Animals↗

PubMed1984

[Interhemispheric relation of brain structures in various functional states of the central nervous system].

In rabbits with indwelled gold electrodes, multiminute oscillations of infraslow activity were recorded within the range from 0 to 1 Hz. The temperature of cerebral structures was recorded from symmetrical areas with the aid of thermocouple. Changes of the functional state were induced by means of 1) unilateral microstimulation of frontal neocortex with 1.5-2.5 microA; 2) administration of neurotropic activators: aethimizole and its analogue: and 3) prolonged administration of ethanole. All these influences sharply increased the natural functional interhemisphere assymmetry inducting a rearrangement of intracentral interrelationships. Use of the neurotropic activators (aethimizole and IEM-476) temporarily restored the normal interaction between the cerebral hemispheres even if the functional interhemisphere asymmetry was still obvious.

Animals↗

PubMed1980

Evaluation of various brain structures in multiple sclerosis with multimodality evoked potentials, blink reflex and nystagmography.

Pattern reversal visual evoked potentials (VEP), blink reflexes, auditory brainstem evoked potentials (ABEP), spinal and scalp recorded somatosensory evoked potentials (SSEP), and nystagmographic records were investigated in 55 patients with multiple sclerosis (MS), who were separated in different categories of probability according to the clinical history, symptoms, and signs. The combined use of different electrophysiological methods forms a sensitive battery for investigating clinically uncertain cases of MS. It was stressed that care should be taken in the interpretation of the electrophysiological findings, since a single lesion in the central nervous system, particularly in the brainstem, may affect different functional systems simultaneously and therefore mimic a disseminated disease.

Adolescent↗

PubMed2002

Chronic stress effects on adenine nucleotide hydrolysis in the blood serum and brain structures of rats.

We have previously observed that adenosine 5'-diphosphate (ADP) hydrolysis was decreased 25% in spinal cord synaptosomes of chronically stressed male rats, while no changes were observed in ATPase activity. In the present study, we investigated the effect of chronic stress on the hydrolysis of adenine nucleotides in two cerebral structures (frontal cortex and hypothalamus) and in the blood serum of male rats. Adult male Wistar rats were submitted to 1-h restraint stress/day for 45 days (chronic) and were sacrificed 24 h after the last session of stress. Adenosine 5'-triphosphate (ATP) or ADP hydrolysis was assayed in the synaptosomal fraction obtained from the frontal cortex and hypothalamus of control and chronically stressed animals. No effects on ADP or ATP hydrolysis were observed in any of the cerebral structures analyzed after chronic stress. On the other hand, reduced ADP hydrolysis was observed in the blood serum of chronic stressed rats. It is possible that the effects observed in the blood serum may represent an adaptation to chronic stress and may reflect different functions of nucleotides and/or enzymes in these tissues. It is possible that altered levels of ADPase activity in the serum may be a biochemical marker for chronic stress situations.

Adenine Nucleotides↗

PubMed2001

Sex differences in the effects of alcohol on brain structure.

OBJECTIVE: This study investigated whether alcoholic women manifest deficits in cortical gray and white matter volumes and ventricular enlargement similar to those seen in alcoholic men. METHOD: Volumetric measures of intracranium, cortical gray matter, white matter and sulci, and lateral and third ventricles were obtained from magnetic resonance images of 42 women and 44 men with DSM-III-R alcoholism and age-matched healthy comparison groups (37 women and 48 men). Groups of alcoholic men and women were matched on age and length of sobriety, but men had a 2.5 times higher lifetime alcohol consumption than women. RESULTS: Women, regardless of diagnosis, had less cortical gray and white matter and smaller third ventricles than men, consistent with sex-related differences in intracranial volume. Alcoholics had larger volumes of cortical sulci and lateral and third ventricles than comparison subjects. Diagnosis-by-sex interactions for cortical white matter and sulcal volumes were due to abnormalities in alcoholic men but not alcoholic women, relative to same-sex comparison subjects. This interaction persisted for cortical sulci after covarying for lifetime alcohol consumption. Slopes relating cortical gray matter and sulcal volumes to age were steeper in alcoholic than in comparison men. Slopes relating lateral ventricle volume to age were steeper in alcoholic than in comparison women. In alcoholic women, longer sobriety was associated with larger white matter volumes. CONCLUSIONS: Alcoholic men and women show different brain morphological deficits, relative to same-sex comparison subjects. However, age and alcoholism interact in both sexes, which puts all older alcoholics at particular risk for the negative sequelae of alcoholism.

Adult↗

PubMedDate not supplied

[Histochemical and electron-microscopic study of brain structures during the acute period of experimental craniocerebral injuries].

Three stages of cerebral metabolism differing in tension were revealed in the acute period of closed craniocerebral trauma. In the mobilization stage (1 hour after trauma) enzymatic reactions reflecting the activity of aerobic and anaerobic glycolysis are sharply intensified. In the resistance stage (from 3 hours to 2 weeks after trauma) stable conversion to anaerobic glycolysis is noted, which leads to marked deficiency in macroergic compounds. Activation of alpha-glycerophosphate, pentose shunt by means of pharmacological agents in combination with hypothermia may be recommended in this stage. In the restoration stage (more than 2 weeks after the trauma) the metabolic processes are gradually normalized and therapy need not be so intensive.

Adenosine Triphosphatases↗

PubMedDate not supplied

[The effect of carbamazepine on the content of monoamines and their metabolites in the brain structures of rats with audiogenic epilepsy].

It was shown that the content of serotonin (5-OT) and 5-oxyindoleacetic acid (5-OIAA) in the temporal cortex, hippocampus and medulla oblongata and the content of dopamine and 3,4-dihydroxyphenilacetic acid in the striatum are increased initially, while the level of norepinephrine in the striatum is reduced in Krushinskiĭ-Molodkina rats genetically predisposed to audiogenic epilepsy in comparison with Wistar rats. Carbamazepine levelled out the changes in the 5-OT and 5-OIAA levels at the peak of the audiogenic attack in the temporal cortex and hippocampus, causing at the same time a sum increase in the content of all monoamines and their metabolites in the medulla oblongata and striatum.

Acoustic Stimulation↗

PubMed1994

In vitro and in vivo effect of the nootropic agent adafenoxate on the 5-HT1 sites in different rat brain structures.

1. The effect of the nootropic agent adafenoxate (a structural analogue of meclofenoxate) on the binding parameters of 5-HT1 receptors in vitro and in vivo in rat cerebral cortex, striatum, hippocampus and hypothalamus was studied. 2. The chronic (100 mg/kg per os for 7 days) adafenoxate treatment produced a significant (24.6%) decrease in the density of 5-HT1 sites in the hippocampus. 3. In vitro adafenoxate inhibited specific [3H]5-HT binding with equal potency in all the regions studied with IC50s in the microM range. 4. It is suggested that the decrease in the density of the 5-HT1 sites in rat hippocampus might contribute to the nootropic action of adafenoxate.

Animals↗

PubMedDate not supplied

[Comparative characteristics of the functioning of brain structures exposed to morphine and D-phenylalanine].

In experiments on rats it was shown that morphine and D-phenylalanine in doses of 5 and 100 mg/kg, respectively, produce a similar by the degree increase of pain reaction thresholds at stimulation of paws through the electrified floor of the chamber. Experiments on rabbits demonstrated that the main factor in morphine action is a decrease of excitability and blood filling of the reticular formation of the midbrain and the central gray matter and an increase of excitability of the dorsal hippocamp without significant changes in the frontal cortex excitability. D-phenylalanine also caused a decrease of excitability of the reticular formation but in contrast to morphine failed to change excitability of the dorsal hippocamp and enhanced excitability of the central gray matter.

Animals↗

PubMed1988

Pituitary-dependent effects of estradiol-17-beta on catecholamine turnover rates, gamma-aminobutyric acid and glutamate concentrations in various hypothalamic and limbic brain structures.

Estrogens exert many effects in a variety of hypothalamic and mesolimbic structures. Whether the actions of the estrogens are direct or indirect, possibly involving anterior pituitary hormones, is largely unknown. We therefore studied catecholamine turnover rates, gamma-aminobutyric acid and glutamate concentrations in various hypothalamic and mesolimbic structures in estrogen-treated hypophysectomized (hypox) rats and compared the measured parameters with those in sham hypophysectomized (sham) animals. Results clearly demonstrate that many of the effects of estrogen require an intact pituitary. Dopamine turnover rates in hypox rats were significantly reduced in the hypothalamus and the striatum, whereas they increased in the medial septum and medial preoptic area in comparison with sham rats. Norepinephrine turnover rates were reduced in the anterior mediobasal hypothalamus, somatosensory cortex and the nucleus accumbens of hypox animals in comparison with the sham-operated animals. In contrast, norepinephrine turnover was accelerated in the mediocortical amygdala and posterior medial basal hypothalamus of hypox rats. A significant reduction of epinephrine turnover was evident in the nucleus accumbens of hypox rats. Gamma-aminobutyric acid concentrations increased in the medial septum, anterior and posterior part of the mediobasal hypothalamus, but decreased in the mediocortical amygdala of hypox animals. Concentrations of glutamate were also decreased in the mediocortical amygdala in hypox animals. These results indicate that many direct effects of estrogens in the brain are accompanied by indirect effects which require an intact pituitary.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2005

[Fatty-acidic content in the brain structures of hypothyroid rats of different age groups].

The content of fatty acids in the cerebral cortex and hippocampus was studied in an experiment on Wistar rats of the three age groups (5-weeks, puberal and old- 20-22 weeks) with an induced hypothyroidism (simulation was achieved by a 2 week prior supplement of L-thyroxin and final monitoring of thyroxin levels in serum). It was determined that the major variations of free fatty acids were noticed in the cerebral cortex and hippocampus among puberal rats, and somewhat lower shifts in premature (5 weeks) and old animals. The increase of free fatty acids in premature rats was registered in spectrum C17-C22. The increase of linoleic and linolenic acids were registered five times higher in hippocampus. In old rats hyperthyroidism was characterized by more apparent shifts in fatty-acidic content of lipids of neocortex and less apparent in hippocampus.

Aging↗

PubMedDate not supplied

[Effect of substance P on the reproduction of memory engrams and on the amino acid composition of brain structures in rats with experimental neurosis].

Formation of experimental neurosis in rats was accompanied in 64% of animals by development of amnesia of conditioned reaction of passive avoidance. Disturbance of mnestic processes was manifested by a change in free amino acids pool including the acids with neurotransmitter properties (GABA, glutamate, glycine). An increase of GABA and glycine content was found in the frontal cortex and an increase of glutamate and GABA--in the hippocampus and striate body. Substance P (125 mkg/kg) administered intraperitoneally against the background of a developed neurosis, produced in 80% of cases an antiamnestic action, accompanied by a statistically significant decrease of GABA content in the frontal cortex, hippocampus and midbrain, and an increase of glutamate in the midbrain. The level of taurine decreased in the frontal cortex, hippocampus and striate body, and increased in the midbrain. Threonine content increased in the striate body and midbrain; there was an increase of taurine, serine and glycine in the midbrain and of glycine in the striate body.

Amino Acids↗

PubMed1992

The effect of p-chloroamphetamine and p-chlorophenylalanine on the level of thyrotropin-releasing hormone and its receptors in some brain structures and lumbar spinal cord of the rat.

The concentration of thyrotropin-releasing hormone (TRH) and the density and affinity of TRH receptors were examined in the ventral and dorsal lumbar spinal cord, nucleus accumbens and striatum of rats with the 5-hydroxytryptamine (5-HT) nerve terminal destroyed with p-chloroamphetamine (PCA), or in animals treated with the inhibitor of 5-HT synthesis p-chlorophenylalanine (PCPA). PCA (2 x 10 mg/kg i.p., 9 and 8 d before killing) and PCPA (3 x 300 mg/kg i.p., 72, 48 and 24 h before killing)--either of them dramatically diminishing the 5-HT and 5-HIAA concentrations in all the examined structures--reduced the TRH level and increased the density of TRH receptors in the ventral lumbar spinal cord. PCPA also reduced the TRH content in the nucleus accumbens. The PCA-induced reduction in the TRH level and increase in the density of TRH receptors in the ventral lumbar spinal cord were significantly attenuated by citalopram (2 x 20 mg/kg i.p., 30 min before PCA), a selective inhibitor of 5-HT uptake. Our results constitute a further proof that coexistence of TRH and 5-HT takes place in the ventral lumbar spinal cord and then indicate that other form(s) of relationship between 5-HT and TRH may exist in some parts of the central nervous system. They also suggest that an up-regulation of TRH receptors occurs in the spinal cord as a result of TRH depletion.

Animals↗

PubMed1991

A magnetic resonance imaging study of schizophrenia: brain structure and clinical symptoms.

Thirty-one patients with schizophrenia and 33 normal control subjects underwent MRI. The BPRS was used to rate clinical symptoms and the NART to estimate pre-morbid IQ. All were right handed. The temporal lobe was significantly smaller on the left than the right in both the control and schizophrenic groups. The amygdala was smaller on the left than the right in controls but not in schizophrenics. The parahippocampal gyrus was smaller on the left side in the schizophrenic group but not in controls. In the schizophrenic group, ventricular enlargement and cerebral atrophy were significantly related to severity of symptoms. Patients with marked negative symptoms had a bilateral reduction in the size of the head of caudate and the two measures were significantly correlated. Patients with marked positive symptoms had larger VBRs and again the clinical and morphometric changes were significantly correlated. There were no morphometric differences between patients with short duration (two years or less) and chronic symptoms.

Adult↗

PubMed2000

Segmentation and measurement of brain structures in MRI including confidence bounds.

The advent of new and improved imaging devices has allowed an impressive increase in the accuracy and precision of MRI acquisitions. However, the volumetric nature of the image formation process implies an inherent uncertainty, known as the partial volume effect, which can be further affected by artifacts such as magnetic inhomogeneities and noise. These degradations seriously challenge the application to MRI of any segmentation method, especially on data sets where the size of the object or effect to be studied is small relative to the voxel size, as is the case in multiple sclerosis and schizophrenia. We develop an approach to this problem by estimating a set of bounds on the spatial location of each organ to be segmented. First, we describe a method for 3D segmentation from voxel data which combines statistical classification and geometry-driven segmentation; then we discuss how the partial volume effect is estimated and object measurements are obtained. A comprehensive validation study and a set of results on clinical applications are also described.

Algorithms↗

PubMedDate not supplied

[Effect of micropolarization of cat brain structures on extinctive inhibition].

The influence of bipolar micropolarization (MCP) (in the range of 0.01--0.1 mca) of the midbrain reticular formation (RF), the dorsal hippocampus (HC) and the temporal cortex (TC) on conditioned behaviour in conditions of extinctive inhibition of an active avoidance reaction to an acoustic stimulus was studied on seven cats in a shuttle chamber. It was shown that: 1) MCP or RF and TC restores the semiextinct conditioned reflex, while MCP of HC deepens its extinction; 2) MCP of RF reduces the conditioned reflex latency, while MCP of HC and TC increases it; 3) during MCP of RF there is an increase in the number of intersignal spontaneous motor reactions and of reactions to surroundings, while during MCP of HC and TC their number decreases; 4) MCP of RF and TC produces no disinhibition, if the conditioned reflex is deeply extinguished. The influence of MCP on conditioned behaviour is regarded as a directed modulation of reproduction of the dominating traces of one of the two contesting temporary connections which determine the achievement or non-achievement of the motor reaction.

Animals↗

PubMed1997

Memory formation: the sequence of biochemical events in the hippocampus and its connection to activity in other brain structures.

Recent data have demonstrated a biochemical sequence of events in the rat hippocampus that is necessary for memory formation of inhibitory avoidance behavior. The sequence initially involves the activation of three different types of glutamate receptors followed by changes in second messengers and biochemical cascades led by enhanced activity of protein kinases A, C, and G and calcium-calmodulin protein kinase II, followed by changes in glutamate receptor subunits and binding properties and increased expression of constitutive and inducible transcription factors. The biochemical events are regulated early after training by hormonal and neurohumoral mechanisms related to alertness, anxiety, and stress, and 3-6 h after training by pathways related to mood and affect. The early modulation is mediated locally by GABAergic, cholinergic, and noradrenergic synapses and by putative retrograde synaptic messengers, and extrinsically by the amygdala and possibly the medial septum, which handle emotional components of memories and are direct or indirect sites of action for several hormones and neurotransmitters. The late modulation relies on dopamine D1, beta-noradrenergic, and 5HT1A receptors in the hippocampus and dopaminergic, noradrenergic, and serotoninergic pathways. Evidence indicates that hippocampal activity mediated by glutamate AMPA receptors must persist during at least 3 h after training in order for memories to be consolidated. Probably, this activity is transmitted to other areas, including the source of the dopaminergic, noradrenergic, and serotoninergic pathways, and the entorhinal and posterior parietal cortex. The entorhinal and posterior parietal cortex participate in memory consolidation minutes after the hippocampal chain of events starts, in both cases through glutamate NMDA receptor-mediated processes, and their intervention is necessary in order to complete memory consolidation. The hippocampus, amygdala, entorhinal cortex, and parietal cortex are involved in retrieval in the first few days after training; at 30 days from training only the entorhinal and parietal cortex are involved, and at 60 days only the parietal cortex is necessary for retrieval. Based on observations on other forms of hippocampal plasticity and on memory formation in the chick brain, it is suggested that the hippocampal chain of events that underlies memory formation is linked to long-term storage elsewhere through activity-dependent changes in cell connectivity.

Animals↗