摘要:

AbstractRabbit vagus nerves were treatedin vitrowith colchicine and halothane, an anesthetic, and the electrical activity monitored. The number of microtubules per square micron of axonal area was measured for each treatment directly from electron micrographs with the aid of a planimeter. Colchicine (10 mM) significantly reduced the number of microtubules per square micron of axonal area from 40 to 16 and had little effect on the electrical activity. Halothane (3 and 10 mM) significantly increased the number of microtubules from 40 to about 55 per square micron of axonal area and blocked the ability of the nerve to propagate impulses within 25 and 10 min, respectively.

ISSN:0022-3034    

DOI:10.1002/neu.480020202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractNeuroplasmic transport phenomena were studied in the nervous system of the cockroach,Periplaneta americana. For proteins, at least two major rates of movement can be resolved by liquid scintillation counting of incorporated C14‐labelled amino acids in serial slices of nerve cord. The slower of the two rates is 1−2 mm/day and appears identical to the “slow” flow well documented for vertebrate neurons. Evidence for an even faster movement is presented.The suitability of the cockroach nerve cord as a model system for the study of the mechanism and control of the movement of the neuroplasmic constituents is di

ISSN:0022-3034    

DOI:10.1002/neu.480020203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe effect of puromycin, puromycin‐aminonucleoside, cycloheximide and acetoxycycloheximide has been tested on the function of the superior cervical ganglion of rat, by recording the postganglionic response evoked by preganglionic stimulation. All the compounds examined exerted a depressant effect, which was prompt and reversible with puromycin and its aminonucleoside, but slow and irreversible with the glutarimides. A correlation of these effects with inhibition of protein synthesis has been examined. The relevance of these findings for experiments on memory disruption reported in the literature is discusse

ISSN:0022-3034    

DOI:10.1002/neu.480020204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractRetinular and eccentric cells ofLimuluslateral eye are stained by intracellular iontophoretic injection of Procion M4R. Eccentric cell branching can be divided into multiple neuropile, long lateral branches and distal collaterals. Retinular cells possess only short axon spines. This morphology is discussed in relation to the known physiology of cell interactions.

ISSN:0022-3034    

DOI:10.1002/neu.480020205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe constituent proteins of the fast (110–150 mm/day) and slow (1.5–2 mm/day) components of axonal transport in the retinal ganglion cells of the rabbit were investigated. The fast and slow components were labelled by intraocular injection of (3H)‐ and (14C)‐leucine, respectively.Subcellular fractionation of the optic nerve and tract and subsequent gel electrophoresis of the fractions showed that most of the soluble proteins moved with the slow phase of axonal transport, whereas only some of the soluble proteins were transported with the rapid phase.Extraction of the microsomal fraction with triton X‐100 resulted in the solubilization of highly labelled proteins belonging to the rapid phase. These proteins showed a relatively low electrophoretic

ISSN:0022-3034    

DOI:10.1002/neu.480020206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe contents of alanine, aspartate, GABA, glutamate, glutamine, glycine, serine, and lactic acid were measured in the cerebral hemispheres, midbrain, cerebellum, and pons‐medulla of rats killed by immersion into liquid nitrogen or by decapitation. The head of each decapitated rat was frozen as described. Only in the cases of lactic acid, alanine and GABA were marked post‐mortem changes observed within a few minutes after death. In rats killed 7 and 15 min after an intraperitoneal injection of (U−14C) glucose, there was a post‐mortem increae in the specific activity of GABA relative to glutamate. These post‐mortem changes in GABA support the idea that of the carbon units oxidized via the tricarboxylic acid cycle approximately 10% pass through the GABA bypath. These data are also consistent with the view that multiple pools of both glutamate and GABA exist in bra

ISSN:0022-3034    

DOI:10.1002/neu.480020207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractD‐methionine was administered intraperitoneally to rats in tracer (2–2.5 μmoles/kg) and large doses (4.7 mmoles/kg) and the brain levels of total (D + L) methionine, as well as of cysteine (+cystine) and glutathione were determined. The effect of co‐administering the convulsant agent, L‐methionine‐DL‐sulfoximine (MSO) was also examined. The administration of tracer doses of C12‐D‐methionine resulted in a doubling of total brain methionine within 4 hours post‐injection, but only in a moderate increase of the levels of cysteine. When C14‐D‐methionine was used as tracer, the peak increase of the isotopic methionine pool and a peak accumulation of 0.35% of the injected radioactivity were noted in the brain within 1.5 hours. When 4.7 mmoles/kg of D‐methionine were administered, total brain methionine and cysteine increased by 4‐ and 3‐fold respectively, the former peaking at 1.5 hr and the latter at 2.5 hr post‐injection. The administration of MSO retarded the attainment of these peaks. It could also be shown that while about 65% of the total brain methionine existed as the D‐isomer 1.5 hr after its administration, only 46% was still present as the D‐isomer 0.5 hr later. When MSO was administered simultaneously with D‐methionine, the corresponding percentage values stood at 70% at 1.5andat 2 hr. The results, therefore, suggest that even though D‐methionine reaches the brain largely unchanged, its uptake and its conversion to the natural L‐isomer may be inhibited by MSO under certain conditions and h

ISSN:0022-3034    

DOI:10.1002/neu.480020208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractWe have studied the subcellular fractionation of a clonal line of glial cells from rat brain. In comparison to rat brain, more of the total protein is collected in the crude nuclear fraction following differential centrifugation. When a crude mitochondrial fraction is prepared and resolved on a density gradient, we find that like brain the glial cell crude mitochondrial fraction is also heterogenous. On a sucrose density gradient, such as that used for the preparation of synaptosomes, the glial cell crude mitochondrial fraction resolves into two major fractions. One of these bands sediments to the same isopycnic density as synaptosomes. This fraction contains 20% of the protein, and 50% of the Na‐K ATPase and acid phosphatase of the crude mitochondrial fraction, but virtually no cytochrome oxidase or choline esterase. The fraction consists of numerous membrane structures resembling plasma membranes when examined by electron microscopy. Because the sedimentation properties of the glial membranes are very similar to synaptosomes, we conclude that synaptosomes prepared on sucrose gradients are probably contaminated by these membrane fragments. In contrast to the separation achieved on sucrose gradients, glial membranes separate from synaptosomes on Ficoll‐sucrose gradie

ISSN:0022-3034    

DOI:10.1002/neu.480020209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

摘要:

AbstractThe energy, ionic, and pH dependence of the influx of labelledL‐glutamic acid has been studied in frog sciatic nerve(1)The addition of 10−2MD‐glucose to the incubation medium was found to inhibit the total influx of glutamic acid from a 10−6M solution by about 40%.(2)The rate of influx was found to be sensitive to the temperature of the bathing medium. Influx was found to increase with temperature in a linear manner from 10°C to 34°C; above 34°C, the rate of influx dropped with increased temperature.(3)At room temperature, the effect of metabolic inhibitors on total influx ranged from 18% inhibition with aresenate to 62% with DNP. Increasing the incubation temperature to 34°C increased the percentage inhibition, a maximum inhibition of 86% occurring with DNP.(4)The cardiac glycoside ouabain (10−3M) slightly inhibited influx (15%).(5)Reduction of the sodium concentration to 2.3 mM resulted in an 82% decrease in total influx. Omission of potassium or a tenfold increase in potassium concentration had no significant effect on influx. Omission of calcium resulted in a slight stimulation of uptake (16%); a tenfold increase in calcium concentration was slightly inhibitory (15%).(6)No relation was found between influx and the pH of the incubation medium. Lowering the pH to 5.4 or raising it to 9.4 had no significant effect on influx.(7)It is concluded thatL‐glutamic acid influx in frog sciatic nerve is probably associated with an energy‐

ISSN:0022-3034    

DOI:10.1002/neu.480020210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY

ISSN:0022-3034    

DOI:10.1002/neu.480020211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1971

数据来源: WILEY