bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transplantation immunity in the brain
Authors: Lodin ZdeněK , HašEk Milan , Chutná Jitka , SláedečEk Miloš , Holáň Vladimír 
Published: January 2005

AbstractThe resistance of animals to allogeneic tumor cells injected into the brain increases with age. The second‐set reaction in the brain of rats appears to be equally effective after preimmunization into the brain and preimmunization into the leg. Also, the presence of cytotoxic antibodies is demonstrable after preimmunization into the brain. These findings suggest that both arcs of the transplantation reaction, the afferent and efferent, are involved in tumor‐cell allotransplantation in the brain.
Electrophysiological, behavioral, and chemical evidence for a noncholinergic, stereospecific site for nicotine in rat brain
Authors: Abood L. G. , Lowy K. , Tometsko A. , Booth H. 
Published: January 2005

AbstractPharmacological, electrophysiological, and biochemical studies have been conducted with rats in an attempt to demonstrate that some of the behavioral effects of nicotine may involve non‐cholinergic brain sites. The behavioral response consisted of a prostration‐immobilization syndrome following the injection of 1−10 μg of nicotine into the region of the lateral or third transmitters and their antagonists, and a number of other psychotropic drugs were ineffective in either enhancing or antagonizing the action of nicotine. Associated with the behavioral response were distinct electrophysiological patterns recorded from electrodes implanted in the dorsal hippocampus in freely moving rats. The characteristic electrical changes consisted of shifts in the frequency from 6 to 8 per second to 2 to 4 per second, and shifts in the amplitude from 300 to 400 μV to 100 to 200 μV. A number of derivatives of nicotine and piperidine were synthesized which were found to be antagonistic to the psychopharmacological and electrical effects of nictotine. The natural (−)‐nicotine isomer was found to be at least 100 times as effective as the (+)‐nicotine on the brain. It was not possible to demonstrate 3H nicotine bending to neural membrane preparations; however, the sereospecific nicotine binding was demonstrable in fresh brain slices and to glass filters. The Kb was 2.0 × 10−8M for glass.
Pyridine nucleotide oxidation‐reduction state of the cerebral cortex in the awake gerbil
Authors: Mayevsky Avraham 
Published: January 2005

AbstractA new approach to study the effect of ischemia on the brain of the awake gerbil is described. The measurement of NADH fluorescence from the surface of the cortex is done by a time‐sharing fluorometer/reflectometer connected to the brain via a flexible light guide and an implanted cannula. The response of the gerbil brain to anoxia and spreading depression is described. By unilateral occlusion of the carotid artery and increase in NADH was measured in the ipsilateral hemisphere.
An X‐ray microanalysis study of differences in concentration of elements in brain cells due to opiates, cell type, and subcellular location
Authors: Cameron Ivan L. , Sheridan Peter J. , Smith Nancy R. 
Published: January 2005

AbstractAdult female Sprague Dawley rats were divided into three groups and given two daily doses of: 1) morphine (25 mg/kg at each injection), or 2) methadone (5 mg/kg), or 3) saline for nine days. Two hours before the rats were killed on day 10, they were given a double dose of the drugs. Fifteen minutes before being killed, some of the morphine‐treated rats were given the opiate antagonist naloxone (2.5 mg/kg), which caused a sudden arousal in these rats. At the time of killing, the preoptic‐hypothalamic region was rapidly removed and frozen in liquid propane to prevent translocation of elements in cells. Frozen 4‐μm sections were cut, freeze‐dried, and electron‐probed in a scanning electron microscope, and energy‐dispersive x‐ray spectra were collected. The characteristic peak‐to‐continuum ratio for all detectable elements was determined in both the nucleus and the cytoplasm of ependymal cells and neurons. The data from nine cells of each type in each rat brain were then subjected to one‐ and three‐way analysis of variance. The results show significant differences in the distribution of elements (sodium, magnesium, phosphorus, sulfur, chlorine, potassium, and calcium) which are dependent upon: 1) subcellular localization, 2) cell type, and particularly, 3) opiate treatment. The behavioral state produced by the opiate is correlated with the effects they have on intracellular concentration of several elements, most notably, sodium.
Histochemical mapping of acetylcholinesterase and butyrylcholinesterase in the medulla oblongata and pons of squirrel (Funambulus palamarum)
Authors: Bhatt D. K. , Tewari H. B. 
Published: January 2005

AbstractThe distribution of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) has been investigated in a series of sections passing through the medulla oblongata and pons of the squirrel brain. A comparison of the two enzymes has given an interesting picture of their selective localization in the different nuclei. Marked AChE activity has been observed in the cranial nerve nuclei. BChE activity in various nuclei of the medulla oblongata and pons is variable and occurs diffusely between the cells. Possible reasons pertaining to marked variation in AChE and BChE contents of various nuclei and fiber tracts have been discussed.
Choline and phospholipid metabolism and the synthesis of acetylcholine in rat brain
Authors: Jope Richard S. , Jenden Donald J. 
Published: January 2005

AbstractThe metabolism of choline by rat brain, plasma, and liver was investigated using combined gas chromatography mass spectrometry following microwave irradiation and treatment with deuterium‐labeled choline. Methods were established to measure simultaneously the concentrations of six choline‐containing compounds and the incorporation of labeled choline into each of them. Intravenous injection of [2H4]‐choline led to initial labeling of choline, acetylcholine, and phosphocholine in rat brain, with all of the label eventually entering the phosphocholine pool. When labeled choline was administered in the diet its rate of incorporation into choline, phosphatidylcholine, and combined choline plasmalogen and lysophosphatidylcholine in the plasma and liver and into choline, acetylcholine, phosphocholine, glycerophosphorylcholine, phosphatidylcholine, and combined choline plasmalogen and lysophosphatidylcholine in the brain were determined. Choline, phosphatidylcholine, and combined choline plasmalogen and lysophosphatidylcholine in the plasma had similar specific activities. In the cortex and the striatum, choline and combined choline plasmalogen and lysophosphatidylcholine fraction generally had the highest specific activities. The time course of the postmortem release of choline by the brain was measured, and the sources of this choline were, sequentially, acetylcholine, glycerophosphorylcholine, and phospholipids.
Cerebral uptake of nicotine and of amino acids
Authors: Sershen Henry , Lajtha Abel 
Published: January 2005

AbstractNicotine is among the compounds that enter the brain very rapidly (blood‐flow‐limited). It also leaves the brain rapidly; by five minutes, 90% exits, an exit somewhat slower than that of water. In spite of rapid exit, brain levels remain higher than levels in blood over a wide range of blood concentrations. Nicotine enters the fetal circulation from the maternal blood; it enters fetal brain but to a smaller extent than adult brain. Nicotine entry is different from that of amino acid: No interaction of amino acid transport and nicotine could be detected. Most close analogs have no effect on nicotine uptake, but at higher concentrations nicotine uptake is saturable. Nicotine and morphine mutually inhibit each other's uptake. The results suggest an uptake compartment (lipid space) for nicotine shared by morphine.
The effect of morphine tolerance on the incorporation of 3H‐leucine into proteins of rat synaptic membranes
Authors: Clouet Doris H. , Ratner Milton 
Published: January 2005

AbstractThe rate of incorporation of 3H‐leucine into proteins of the synaptic junctional and nonjunctional membranes and synaptic vesicles of rat brain has been examined in control and morphine‐tolerant rats. There are no discernible differences between control and tolerant animals in amount of protein as measured by densitometric tracings of dye‐stained proteins separated by acrylamide gel electrophoresis from the three membrane fractions of whole brain areas. However, there are differences in the turnover of membrane protein: three vesicle protein bands and one junctional‐membrane protein band are significantly more highly labeled, and one junctional‐membrane protein is significantly less highly labeled by 3H‐leucine in samples from tolerant rats. Of these, the two junctional‐membrane proteins can be tentatively identified as components of the postsynaptic densities, and one of the vesicle proteins as tubulin.
In vitro formation of neuroglial synapses
Authors: Palacios‐Prü Ernesto , Palacios Laura , Mendoza Rosa V. 
Published: January 2005

AbstractNeuroglial synapses have been systematically observed in histotypical cerebellar rotary tissue cultures. These axoglial contacts appear as excitatory‐like synapses in which the presynaptic element contains rounded synaptic vesicles accumulated at the presynaptic active zone. The postsynaptic structures were always the somata as well as processes of astrocytic glial cells. The axoglial contacts appear in these cultures when they are prepared from 16‐day‐old chick embryos cerebellum and cultivated during 6 days. To explain these neuroglial interrelationship it has been suggested as a working hypothesis that glial and nerve cells develop plastic capacities in order to establish synaptic contact in the in vitro conditions.
Effects of polarizing currents and repetitive stimulation on the uptake of amino acids by peripheral nerve
Authors: Wheeler Darrell D. 
Published: January 2005

AbstractThe effects of polarizing currents and repetitive stimulation on the uptake of representative amino acids have been studied in peripheral nerve. Glutamic acid, lysine, pheylalanine, and GABA were chosen for study as representatives of different carrier‐mediated transport mechanisms. Depolarizing currents inhibited uptakes of glutamic acid, lysine, and GABA; maximum inhibitions were 56.1%, 20.0%, and 16.7%, respectively. Pheylalanine uptake was not inhibited by polarizing currents under any experimental conditions. Only glutamic acid uptake was inhibited by hyperpolarizing current, with a maximum inhibition of 43.9%. Stimulation had no significant effect on uptake of lysine, phenylalanine, or GABA but was found to potentiate uptake of glutamic acid by 12%.
Uptake of 2‐deoxy‐D‐glucose by cortical synaptosomes from the long—evans rat
Authors: Wheeler D. D. , Hollingsworth R. G. 
Published: January 2005

AbstractUptake of 2‐deoxy‐D‐glucose (2‐DG) has been studied in synaptosomes from the Long–Evans rat. Although there are some differences, the results are generally similar to those reported for Sprague–Dawley rats. Both D‐glucose and 2‐DG are taken up by the same carrier, since D‐glucose was found to inhibit uptake of 2‐DG. Uptake is highly dependent on a source of metabolic energy, since incubation at 0°C completely eliminated uptake, while 10−3 M 2, 4‐dinitrophenol (DNP) inhibited uptake by 76.5%.Uptake has also been measured as a function of both 2‐DG and sodium concentration and the data fitted to a model. Sodium is found to inhibit uptake. A model assuming noncompetitive inhibition by sodium gives best fit to the data. Thus both Kt and apparent Vm are dependent on the sodium concentration. Although these effects are small, Kt increases with [Na], while apparent Vm declines.
Melanotropic peptides: Presence in brain of normal and hypophysectomized rats, and subcellularly localized in synaptosomes
Authors: Loh Y. Peng , Zucker Lloyd , Verspaget Hein , van Wimersma Greidanus Tjeerd B. 
Published: January 2005

AbstractA major and several minor tricholoroacetic acid (TCA) soluble, bioassayable melanotropic peptides, as well as bioreactive and immunoreactive α‐MSH have been found in the hypothalamus, olfactory bulb and cerebral cortex of normal and hypophysectomized rats. By employing subcellular fractionation procedures it was demonstrated that α‐MSH and the major TCA soluble melanotropic peptide (MMPB) were localized in synaptosomes and were released by hypoosmotic shock. The analysis of MMPB by electrophoretic and chromatographic procedures reveals that it is not ACTH4−10, ACTH1−10, ACTH1−24, NAcACTH1−10 or α‐MSH. MMPB was found to cross‐react with an antiserum specific for the Lys‐Pro‐Val NH2 sequence in α‐MSH, indicating that this C‐terminal sequence of α‐MSH may be present in its structure. MMPB was also shown to differ electrophoretically from the two major TCA soluble melanotropic peptides found in the neurointermediate lobe of the pituitary. In view of their synaptosomal localizations MMPB and α‐MSH may play a role in synaptic function in the nervous system.
Mass spectrometric identification of Cu, Zn, Fe, Co, Mn, Mg, and Pb in mammalian brain
Authors: Hui K.‐S. , Davis B. A. , Boulton A. A. 
Published: January 2005

AbstractCombining the techniques of thin‐layer chromatography (TLC) and mass spectrometry, we unambiguously identified the trace metals Cu, Zn, Fe, Pb, Mn, Co, and Mg in the brain of a female human who had no evidence of any pathologic disease in the central neveous system, and in brains from mouse, rat, guinea pig, and rabbit. These trace metals were also found in anatomic regions of human brain: cortex (gray), cortex (white), caudate nucleus, putamen, hippocampus, and thalamus, and in anatomic regions of rat brain: hypothalamus, cerebellum, stem striatum, and “the rest.” The metals were characterized from the color and Rf values of their tetraphenylporphyrin chelates on TLC and from the mass and pattern of molecule ion cluster of the mass spectrum. The unexpected presence of lead in the brain is discussed.
Soluble protein and peptide pattern from different regions of rat brain during pre‐ and early postnatal development
Authors: Zeuchner Jenny , Rosengren Lars , Rönnbäck Lars 
Published: January 2005

AbstractIsotachophoretic pattern from phylogenetically different regions of rat brain during pre‐ and early postnatal development were studied. Four main observations were made: (a) The patterns were greatly similar during maturation of the respective regions studied; (b) One complex of peaks disappeared or decreased in quantity during the 2nd and 3rd weeks of postnatal development; (c) New peaks appeared and accumulated during the same period; (d) Slight differences were observable in the different regions studied.
Membrane fluidity and fatty acid composition of phospholipids in erythrocyte membranes of patients with huntington disease
Authors: Abood Mary E. , Butler Madeline 
Published: January 2005

AbstractA study was undertaken to determine whether alterations in the configuration of erythrocyte membranes of patients with Huntington disease, reported by other investigators, could be reflected in membrane fluidity‐viscosity. Since membrane fluidity appears to be related to the fatty acid composition of membrane phospholipids, these were also examined. Membrane fluidity, which was determined by measuring the intrinsic fluorescence of membranous tryptophan, was found to be normal. Although the range of fatty acid distribution within the various phospholipids tended to vary somewhat, the pattern was not significantly different from that of the controls.
Relative normophagia and organ growth in growth‐retarded weanling rats with dorsomedial hypothalamic lesions
Authors: Bernardis Lee L. , Bellinger Larry L. 
Published: January 2005

AbstractWeanling rats with ventromedial (VMNL) and dorsomedial (DMNL) hypothalamic lesions and sham‐operated controls were maintained up to 198 days after operation. Food intake was measured throughout the experiment and organ weights were recorded at various periods of sacrifice. Comparisons were made between controls and VMNL and DMNL rats, respectively. Food intake and organ weights were expressed in absolute terms and relative to body mass and Kleiber's “metabolic size.” VMNL rats were always normophagic and showed lower organ weights, regardless of manner of computation. Rats with DMNL, on the other hand, were absolutely hypophagic but relatively normophagic for considerable periods of time when food intake was referred to body mass. A similar relationship obtained for organ weights. The data fit well with previous results and with a hypothesis that holds that DMNL bring about a “resetting” of some central nervous control system that not only allows the rat so operated to subsist on lower substrate levels but also regulates normal growth in relation to body mass.
Mesencephalic lesions in female rats resulting in normophagia and reduced body weight
Authors: Bellinger L. L. , Bernardis L. L. , Brooks S. 
Published: January 2005

AbstractThe effects of bilateral mescencephalic lesions in the area of the ventral noradrenergic bundle (VNA) were studied in immature and mature female rats. The food intake consumption of the immature lesioned rats did not differ from sham operated controls whether fed a chow or high fat diet.However, after the surgery the body weights of the two groups began to diverge with the immature lesioned rats obtaining a significantly lower body weight. By the end of the study the immature lesioned rats were also significantly shorter than the controls. Both groups showed normal body composition throughout the measurement period. Upon refeeding after a one day fast the immature female rats defended their lower than normal pre‐fast body weight. These data are in good agreement with our earlier findings using immature male rats. The mature lesioned animals also showed normal food consumption when fed a chow type diet. However the lesioned animals did show a brief hyperphagia when placed on a high fat diet. Unlike the immature lesioned rats the body weight of these lesioned animals did not differ from their sham operated controls. It is suggested that lesions in the area of the VNA may result in hyperphagia or, in no effects on food intake or body weight as reported by others or normophagia with reduced body weight. Exact lesion placement may be responsible for these divergent findings.
Cerebral amino acid levels and uptake in rats after portocaval anastomosis: I. Regional studies in vivo
Authors: Zanchin Giorgio , Rigotti Paolo , Dussini Noemi , Vassanelli Paolo , Battistin Leontino 
Published: January 2005

AbstractAmino acid levels have been determined in plasma and in four cerebral regions of rats one month after portocaval shunt. Many plasma amino acids are significantly lowered (asparagine, glutamine, threonine, serine, alanine, valine, leucine, isoleucine, cystine, lysine), while others remain unchanged (taurine, glycine, proline, tryptophan, ornithine, histidine, arginine). Asparagine and glutamine levels are significantly higher than in normal rats, and a net increase of tyrosine (100%), phenylalanine (50%) and citrulline (50%) is evident. In the shunted rat brain the most prominent feature is a very large rise (up to fivefold) of tyrosine, phenylalanine, histidine, citrulline, tryptophan, and glutamine uniformly in the tested regions. Other neutral amino acids are slightly increased. Lysine and arginine are decreased in cerebellum and pons‐medulla; taurine, in forebrain and cerebellum.Cerebral permeability to L‐amino acids was studied in vivo. Neutral amino acid permeability is greatly increased, whereas basic amino acids show a net decrease in their rate of passage from blood to the brain. No changes are observed for GABA and glutamic acid. These data suggest an altered permeability of the cerebral capillary membranes, which seems to be selective for the different amino acid transport classes. Competitive inhibition experiments demonstrate that the increased brain permeability to neutral amino acids after portocaval shunt is due to an enhancement of the saturable transport. The sharp rise in the brain of some essential neutral amino acids (phenylalanine, tyrosine, tryptophan, histidine), largely exceeding their changes in plasma, and the slight cerebral increase of other neutral amino acids despite their lowered level and the rise of competing amino acids in the plasma, is consistent with our observation of enhanced transport for the neutral class.In hepatic encephalopathy, correction of the altered plasma amino acid levels has been reported to improve the clinical status. If this result is connected to the concomitant correction of the brain amino acid levels, carefully selected competitive inhibition among various plasma amino acids could be a useful therapeutic tool in this pathologic condition. However, the increased activity of the neutral amino acid transport system adds a new factor to the problem, since it probably implies that the competing amino acids will accumulate to unphysiological levels in the brain.
Effects of catecholamines and related compounds on horizontal cells in the fish retina
Authors: Negishi K. , Drujan B. D. 
Published: January 2005

AbstractThe effects of catecholamines (CA) and certain related compounds in the superfusate were examined on the intracellularly recorded potential from horizontal cells in the fish (Eugerres plumieri) retina. The stimulated retinal area consisted of a central spot 1.0 mm in diameter and an annulus 2.0 mm in inner diameter and 4.0 mm in outer diameter; both forms of monochromatic stimuli were centered relative to the recording microelectrode. Each of the CA (dopamine, noradrenaline, and adrenaline) produced an analogous effect on the hyperpolarizing response of all types of horizontal cells. The depolarizing response of the C (R/G)‐type cells was found to change variably with the CA. The effect of dopamine (DA) among the CA was most pronounced when they were used at an equivalent amount. With 10–50 μM, the action of DA was variable but in general its effect was to increase slightly both center and surround responses. In some cases, however, DA initially augmented the surround and reduced the center response. Large amounts of the CA (100–200 μM) augmented the center response and attenuated the surround response considerably; these reciprocal changes usually were associated with moderate depolarization of the cells (5–10 mV). Recovery then occurred in 15–20 minutes. These results indicate that the CA, up to a certain amount, do not directly affect the transmission from photoreceptors to horizontal cells, since the center response became larger. At the same time, the lateral propagation of an S‐potential appears to be selectively affected by the CA, suggesting that the adrenergic system participates in this phenomenon. When an excess of these compounds (200–500 μM) was given, the cells were rapidly depolarized to near 0 mV and eventually the light‐induced responses were abolished. Large amounts (5–10 mM) of metabolic products of the CA (DOPAC and VMA) were found to reduce the center response slightly more than the surround. α‐Methylnoradrenaline, 5‐hydroxydopamine, and serotonin also caused the same but less effect on horizontal cells as did DA. Reserpine and clonidine mimcked the CA effect only if these compounds had been preceded by repeated applications of one of the CA or if the retina had been pretreated with Marplan®. Propranolol, haloperidol, and apomorphine affected neither the horizontal cell membrane potential nor the CA effect. However, phentola‐mine in large amounts (500 μM) markedly diminished the DA action. Therefore, α‐adrenergic receptors appear to he involved in the UA‐induced changes observed in the horizontal cell response.