Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “brain structure”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMedDate not supplied

[Effect of chronic ethanol consumption on the thyroxine hydroxylase activity of various brain structures in rats].

The effect of chronic (8-week long) 5 percent-ethanol consumption on the activity of tyrosine hydroxylase on the rat brain hypothalamus, striatum and midbrain was studied. In rats with strong ethanol prefence the enzyme activity was found to increase by 65-86 percent in the hypothalamus and to diminish by 52-68 percent and 29-68 percent in the midbrain and striatum, respectively. In rats with weak ethanol preference the enzyme activity in the brain striatum and midbrain remained unchanged, while in the hypothalamus it decreased by 25-40 percent. Chronic ethanol consumption had no effect on the inhibition of the enzyme activity neither by dopamine (8.0 X10(-4)M), nor tyrosine (in an inhibitory concentration of 3.7X(10(-4)M).

Animals↗
PubMed2001

Brain structures and neurotransmitters regulating aggression in cats: implications for human aggression.

1. Violence and aggression are major public health problems. 2. The authors have used techniques of electrical brain stimulation, anatomical-immunohistochemical techniques, and behavioral pharmacology to investigate the neural systems and circuits underlying aggressive behavior in the cat. 3. The medial hypothalamus and midbrain periaqueductal gray are the most important structures mediating defensive rage behavior, and the perifornical lateral hypothalamus clearly mediates predatory attack behavior. The hippocampus, amygdala, bed nucleus of the stria terminalis, septal area, cingulate gyrus, and prefrontal cortex project to these structures directly or indirectly and thus can modulate the intensity of attack and rage. 4. Evidence suggests that several neurotransmitters facilitate defensive rage within the PAG and medial hypothalamus, including glutamate, Substance P, and cholecystokinin, and that opioid peptides suppress it; these effects usually depend on the subtype of receptor that is activated. 5. A key recent discovery was a GABAergic projection that may underlie the often-observed reciprocally inhibitory relationship between these two forms of aggression. 6. Recently, Substance P has come under scrutiny as a possible key neurotransmitter involved in defensive rage, and the mechanism by which it plays a role in aggression and rage is under investigation. 7. It is hoped that this line of research will provide a better understanding of the neural mechanisms and substrates regulating aggression and rage and thus establish a rational basis for treatment of disorders associated with these forms of aggression.

Aggression↗
PubMed1983

Congenital structural brain defects in the deaf dalmatian.

Deafness in dalmatian dogs in known to be congenital. It has been reported that the condition is manifested in structural defects of the sensitive lamina of the organ of Corti. In a study of deaf puppies, examined as they became available, this was found to be in doubt. Moreover, a characteristic gross reduction of area was found in the structure of the acoustic cortex in affected puppies. Extension of the morphometric studies further showed that the acoustic pathways were generally attenuated in keeping with the changes in the cortex. Consideration is given to the probability that the condition develops centrally rather than peripherally. Thus instead of the central components failing to develop because of lack of evocative stimulus from the end organ it is envisaged that the peripheral organ regresses because of incomplete innervation by central outgrowth.

Animals↗
PubMed2005

Soemmerring's work on the nervous system: a view on brain structure and function from the late eighteenth century.

Samuel Thomas Soemmerring (1755-1830) was an encyclopaedic anatomist and one of the most experienced and renowned neuro-anatomists in the late eighteenth century. His description and illustration of the brainstem with its still accepted classification of cranial nerves (1778), the discovery of the acervulus in the epiphysis (1785), his demonstration of the crossing of the optic nerve fibres (1788), and of the macula lutea in the retina of the eye he had discovered in 1791, won him great recognition. Probably, unaware of Francesco Gennari's (1750-1797) and Félix Vicq d'Azyr's (1748-1794) observation, Soemmerring in the final years of the eighteenth century saw the broad white line running through the calcarine cortex of the occipital lobe. Soemmerring's comprehensive textbooks on the nervous system Vom Hirn and Rückenmark, 1788/1792, and Hirn- und Nervenlehre as part of his anatomical handbook Vom Baue des menschlichen Körpers, 1791/2nd edn, 1800, comprise all the knowledge in the field of neuro-anatomy at his time. Although the structure-function relationships mentioned are generally hypothetical, Soemmerring was convinced that mental faculties are executed in certain brain regions. In his treatise Uber das Organ der Seele, 1796, he localized the functions of the soul within the cerebrospinal fluid, which should come into close contact with the demonstrated and presumed nerve endings in the walls of the ventricular cavities. This last attempt of a synthesis of anatomy and metaphysics provoked passionate discussions and was criticised for epistemological reasons. Nevertheless, Soemmerring had moved the brain into the centre of the science of man what led to far-reaching consequences in the complexity of the discourse about man.

Brain↗
PubMed1994

Triiodothyronine does not affect the average incorporation of L-[35S]methionine in rat brain structures.

The autoradiographic method with L-[35S]methionine was used to examine the effect of acute administration of L-triiodothyronine on local rates of brain protein synthesis in free-moving adult rats. Triiodothyronine was given intraperitoneally at doses of 12.5 or 25 micrograms kg-1. It did not modify the rate of plasma methionine incorporation in the 40 brain regions examined, despite a 4- to 8-fold increase of plasma free triiodothyronine levels. Biochemical analysis confirmed that triiodothyronine (25 micrograms kg-1) had no apparent effect on the overall rate of protein synthesis in the brain as a whole. These results suggest that changes in the circulating levels of thyroid hormones do not exert a general and direct metabolic effect in brain of intact adult rats.

Animals↗
PubMed1986

[Changes in the catecholamine content of brain structures in rats subjected to immobilization stress].

The changes in DOPA and catecholamine (adrenaline, noradrenaline, dopamine) levels were investigated in noradrenaline- and dopamine-synthesizing brain nuclei of Wistar rats after prolonged immobilization stress on catecholamine analyzer (BAS, USA) using HPLC technique. Distinct DOPA and catecholamine changes were observed in locus ceruleus + nucleus subceruleus (1. c + n. sc) and substantia nigra at any stage after immobilization (right after immobilization and 15 and 30 days later). The most prominent alterations in noradrenaline content were detected in 1. c + n. sc. 30 days after immobilization NA level in these nuclei was 1.5 times higher, as compared to the control one. It is suggested that the increasing noradrenaline level in 1. c + n. sc. plays a defensive role in survival of rats after immobilization stress.

Animals↗
PubMed1981

[Transport ATP-ase activities in different brain structures during development of experimental neuroses in rats].

Typical alterations in activity of transport ATPases were observed in crude mitochondrial fractions isolated from various rat brain parts after chronic stressor effects. In the acute period of stress reaction activity of Na+, K+-ATPase was increased in synaptosomes of frontal cortex, hypothalamus and hippocamp. The enzymatic activity normalized after chronic action of the stressor agents. But under these conditions the activity of Mg2+-ATPase was distinctly decreased in cortex, hypothalamus and in pons Varolii.

Adenosine Triphosphatases↗
PubMed1981

Structural brain deficits in schizophrenia. Identification by computed tomographic scan density measurements.

Research has suggested the presence of brain damage as a cause or concomitant of chronic schizophrenia. The most recent research in this area has been the identification of abnormalities in schizophrenia by computed tomographic (CT) scans. A study was done to investigate localized changes in CT scan density numbers in the brains of schizophrenic patients, as opposed to the brains in normal control subjects. Twenty-four normal subjects and 23 schizophrenic patients were tested with CT scans. Density measurements in each area of the brain (left, right, anterior and posterior) were compared to three separate CT scan levels. Of six measurements of anterior left-hemisphere density, it was found that five showed lower density in schizophrenic brains, as compared with normal brains. Of the remaining 18 measurements that evaluated other areas of the brain, only three differentiated between schizophrenic patients and normal subjects. The results support the hypothesis that there are primary structural deficits in some schizophrenic patients, and these deficits are centered in and around the anterior area of the left (dominant) hemisphere. The results also demonstrated further implications.

Absorptiometry, Photon↗