摘要:

SUMMARYSulphatides have been isolated by a newly developed method from the brain white matter of normal human adult and child, and of two patients with metachromatic leucodystrophy.Only galactose was found in chromatographic analysis of the carbohydrate component. Following permethylation of the sulphatides, the methylated hexose, in all cases, was 2,4,6‐trimethylgalactose.The sulphate group is located solely at the C‐3 position of the galactopyranose moiety, and in metachromatic leucodystrophy, although there is an accumulation of sulphatides, their composition and structure remain nor

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04262.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYSulphatides and cerebrosides from white matter of brains of patients with metachromatic leucodystrophy (MLD) have been isolated and compared in fatty acid composition to those glycolipids found in MLD kidney tissue. A marked difference in glycolipid composition was found between the brain and kidney tissues. The sulphatides accumulated in MLD kidney have the same fatty acid profile as those found in normal kidney tissue and are typical‘kidney sulphatides.’The neutral glycolipids of MLD kidney retain larger amounts of the longer chain acids than do the cerebrosides of MLD brain white matter and thus resemble more closely in fatty acid composition, glycolipids of normal tissue.Structurally, the sulfate group is located at the C‐3 position of the galactose molecule in sulphatides from normal and MLD tissue.As in the brain white matter, the sulphatides which accumulate in the kidney tissue of patients with MLD are normal in structure and compos

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04263.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYThe detailed distribution of lactate dehydrogenase and monoamine oxide has been described at various levels through the pons and mesencephalon of the brain of the squirrel monkey. A comparison of the two enzymes has given an interesting picture of their selective localization in the different nuclei. Particular attention has been paid to select sections at comparative levels. Marked monoamine oxidase activity has been observed in the nucleus interpeduncularis, the nucleus centralis superior, the nucleus annularis, and in the neuropil and in the cytoplasm of neurons of some other nuclei. Particularly strong lactate dehydrogenase activity has, however, been observed in the corpus geniculatum laterale and mediale, the nucleus pulvinaris, the superior and inferior colliculi, the substantia grisea centralis and some of the nuclei of cranial nerves.

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04264.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYThe concentrations of free amino acids in plasma, CSF andin vivodialysates of peripheral blood (neck sac fluid) and central nervous tissue (brain sac fluid) from each of five dogs (neck sac fluid from four of five dogs) were determined by ion‐exchange chromatography. Dialysates were obtained by implanting small dialysis sacs filled with a dextran‐saline solution into the subcutaneous tissue of the neck or the parenchyma of the brain at least 10 weeks before sample collection.The mean plasma concentration of most amino acids was within the range of values reported in the literature for human or dog plasma. The concentrations of most amino acids were higher in the neck sac fluid than in plasma; this discrepancy, however, was, for the most part, small and could most likely be accounted for by falling plasma free amino acid levels prior to sample taking. Previous conclusions that the CSF concentrations of most amino acids are lower than plasma concentrations are confirmed, although the present work indicates that there may be considerable individual variation in the CSF/plasma distribution ratio with respect to most amino acids.In the brain sac fluid the concentration of nearly every amino acid was consistently higher than that in CSF and lower than that in the neck sac fluid. The potassium concentration in the brain sac fluid was significantly higher than, and the total osmolality significantly lower than, those in the neck sac fluid. On the assumption that the brain sac fluid represents a dialysate of the brain extracellular fluid, these results contradict recent findings (Bitoand Davson, 1965; 1966) indicating that the potassium concentration of the cortex extracellular fluid is lower than that of ventricular or cisterna magna CSF and certainly lower than that of plasma. Because of this and on the basis of consideration of the reaction of the brain to a foreign body, the possibility that the implanted brain sac lay on the‘blood side’of the bloodbrain barrier was suggested. Some implications of this possibility are di

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04265.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYThe distribution ofN‐acetyl‐l‐aspartic acid in the rat brain has been studied by means of a new gas‐chromatographic method. The results obtained concern twelve different brai

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04266.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYThe distribution of indicator solutes (inulin, sucrose, raffinose, thiocyanate, chloride, and isethionate) and the swelling in slices of adult cat cerebral cortex incubatedin vitrohave been investigated for a variety of incubation media and conditions. Where appropriate, these data have been compared with analogous data obtained on cat cerebral cortexin vivo(Bourkeet al., 1965) and with data previously reported for slices of rat cerebral cortex (Pappiusand Elliott, 1956; Pappiuset al., 1962) and guinea pig cerebral cortex (Varonand McIlwain, 1961; Keeseyet al., 1965) incubatedin vitrounder comparable conditions.In addition to substantial agreement of present data with previously reportedin vitrodata, a number of new findings have been added by the present study: (a) a component of slice swelling which is K+‐dependent; (b) the association of slice swelling with presence of a diffusible, external anion (Cl−) and its prevention by replacement with a relatively non‐diffusible anion (isethionate−); (c) variation of the size of slice chloride spaces as a direct function of slice swelling; (d) dependence of the size of slice fluid spaces accessible to inulin and sucrose upon time, during incubation, of solute addition and upon K+concentration of the incubation medium; (e) indications of the dynamic and presumably metabolically‐dependent nature of indicator solute distribution; and (f) the mobility of a portion of the fluid of swelling associated with changing the K+concentration but not the tonicity of the medium during incubation.At least five operationally‐defined fluid compartments may be inferred from the present data : (1) interstitial or extracellular space(s) readily accessible to all solutes and of a size which can be minimally estimated from direct determinationsin viuo; (2) additional fluid space(s) accessible to most solutes, including inulin and sucrose, under apparently suboptimal conditions of slice metabolismin vitro; (3) fluid space(s) prone to swell underin vitroconditions and readily accessiblein vitroto chloride and thiocyanate but not to inulin or sucrose; (4) fluid space(s) which swell reversibly in the presence of added external K+(or Rb+) and are inaccessible to all usual indicator solutes; and (5) after exclusion of the foregoing, the remaining fluid presumably comprising most of the intracellular space(s).The data have been discussed in terms of the morphological complexity of cerebral cortex, in terms of applicability to studies of cortical electrolyte distribution, and in terms of the general problem of delineating cerebral intersti

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04267.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYThe contents of K+, Na+and Cl−in various incubation media and in slices of adult cat cerebral cortex incubatedin vitrounder a variety of conditions have been determined in conjunction with studies on slice swelling and fluid compartmentation reported in the preceding paper (Bourkeand Tower, 1966).Cortical slices incubated in media containing 16 Or 27 mm‐K+exhibit contents of K+and Na+most nearly comparable to those foundin viuo. Substitution of isethionate−For Cl−or omission of Ca2+in such media have little effect on slice cation composition. Rb+can effectively substitute for K+, but substitution of Li+or choline+for most of the naf in incubation media is associated with accumulation of these cations in slices at the expense of both K+and Na+.Compared to valuesin vivofor net contents and/or concentrations of electrolytes in the non‐sucrose spaces of cortical slices, conditions yielding most favourable datain vitroappeared to be incubation of cortical slices in 16 mm‐K+medium or in 27 mm‐K+medium with either omission of Ca2+or replacement of Cl−by isethionate.Essentially complete inhibition of maintenance of K+and extrusion of Na+in slices of cat cerebral cortex occurs upon incubation with 10−5or 10−4m‐ouabain, with 50 per cent inhibition of cortical slice electrolyte metabolism occurring at about 8 × 10−7m‐ouabain.Cortical slices incubated in 27 mm‐K+medium in the presence of42K exhibited rates of exchange and turnover of slice K+(in non‐sucrose spaces) of 0·7 μequiv./min and 6.45 per cent respectively. In the presence of 10−5m‐ouabain, a maximal ratio of slice specific activity/medium specific activity is attained within about 5 min after42K addition, compared to>20 min for control slices. In neither case does the maximal specific activity ratio exceed about 0.85; this suggests that some 10‐15 per cent of total cortical K+comprises a “slowly exchangeable” fraction.In the presence of Ca2+(1.3 mm) slice oxygen consumption is markedly stimulated (39 per cent) and aerobic glycolysis is markedly depressed (54 per cent) in the presence of 10−5m‐ouabain; whereas on omission of Ca2+from incubation media, both respiration and glycolysis are normally stimulated but, with 10−5m‐ouabain present, both are significantly depressed (20 per cent and 37 per cent respectively). Possible relevance of these effects to mobilization of tissue Ca2+by ouabain and to effects of intracellular Ca2+on

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04268.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYStudies on swelling and fluid compartmentation have been carried outin vitroon incubated slices of cerebral cortex from kittens 1.5‐120 days post‐natal age and on incubated sections of corpus callosum and slices of liver and kidney cortex from adult cats. The findings have been compared with analogous data for incubated slices of adult cat cerebral cortex, studied under identical conditions (Bourkeand Tower, 1966a,b), in order to identify the probable morphological correlates of fluid and electrolyte distribution.Incubated cortical slices from neonatal (1.5‐4‐day‐old) kittens exhibit none of the relevant characteristics of slices from adult cerebral cortex. By 1 month post‐natal age, K+‐dependent swelling of slices becomes demonstrable, and the K+and Na+contents of slices approximate adult levels. Both these developments coincide with the morphological and physiological maturation of cortical neurons. At 3 months post‐natal age, slice swelling accessible to C1−but not to sucrose becomes observable and the dependence of sucrose space size on time, during incubation, of solute addition becomes demonstrable. Both these developments follow completion of axonal myelination in the cortex but coincide with the period of cortical glial cell proliferation.Incubated sections of corpus callosum from adult cats exhibit none of the relevant characteristics observed for cortical slices under identical conditions. Tissue swelling is minimal and uninfluenced by K+concentrations of incubation media. Tissue fluid spaces accessible to sucrose are approximately twice the size of spaces accessible to inulin. In general, qualitatively similar results have been obtained for incubated slices of cat liver or kidney cortex or for incubated sections of rat diaphragm under the same conditions. A behaviour for glial cells (? astrocytes) in cerebral cortex under such in vitro conditions distinctly different from behaviour of subcortical glial c

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04269.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

The uptake of [U‐14C]glucose and [2‐14C]acetate into lipids was measured in brain slices from anoxic, unilaterally ischaemic, unilaterally anoxic‐ischaemic, and control rats. The rate of incorporation was significantly decreased in the brain slices from the treated animals except for the contralateral hemisphere of the unilaterally ischaemic animals. Also, there was no significant difference between the anoxic and the anoxic‐ischaemic cerebral hemispheres of the anoxic‐ischaemic animals. Fractionation of the total lipid extract demonstrated that the decrease in incorporation was general and not due to any particular class

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04270.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY

摘要:

SUMMARYReserpine (0.1 mg/kg/day) was administered to rats from 11 through 30 days of age. During and after administration of reserpine, concentrations of catecholamines, epinephrine and norepinephrine, in the brain were estimated. Levels of catecholamines were about 30 per cent of normal during the period of reserpine administration. Approximately 3 weeks were required for these levels to return to normal. When animals were 95‐100 days of age, they were deprived of food and were trained to press a bar for food. When the rate of responding became stable, the animals were subjected to three successive extinctions at daily intervals and the increase in response rate after the onset of each extinction was determined. This extinction‐induced increase in response rate was greater for previously reserpinized animals than controls during the second and third extinctions, but not the first. These findings are interpreted as a decreased ability of the animals, reserpinized during infancy, to learn to respond discriminatively during non‐reinforcement (extinction). Thus, an effect of reserpine administration during infancy on a type of behaviour in the adult has been demonstrated. This occurs after the catecholamine‐depleting effect of the reserpine has been fully dis

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1966.tb04271.x

出版商:Blackwell Publishing Ltd    

年代:1966

数据来源: WILEY