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991.
N-Methyl-D-Aspartate receptors in acquisition of the short-term memory in the honeybeeApis mellifera
N. G. Lopatina I. V. Ryzhova E. G. Chesnokova L. A. Dmitrieva 《Journal of Evolutionary Biochemistry and Physiology》2000,36(3):294-300
Role of NMDA receptors in the process of associative learning has been studied in the honeybeeApis mellifera L. in behavior experiments, using method of conditional reflexes. To determine pharmacological profile of NMDA receptors,
effects of Mg2+ ions, NMDA, glycine (Gly), antagonist of the glycine site 5,7-dichlorokynurenic acid (DCK), competitive antagonists of NMDA
receptors: D,L-2-aminophosphovalerate (APV), L-2-aminophosphobutyrate (APB), and D-glutamyl-aminomethylphosphonic acid (GAMP)
as well of antagonists of NMDA receptor ion channels MK-801 and ketamine (Ket) were studied on acquisition of alimentary conditional
reflex and its retention in memory. NMDA increased capacity for learning by stimulating shortterm memory. The NMDA receptor
co-agonist Gly activated this NMDA effect. DCK eliminated the NMDA and Gly stimulatoty effects. All tested antagonists at
millimolar concentrations inhibited associative function. The data obtained confirm our hypothesis about participation of
NMDA receptors in processes of formation of short-term memory in the honeybeeApis mellifera and suggest that functional characteristics of the NMDA receptors involved in the process of associative learning in the
honeybee resemble those in mammals. 相似文献
992.
The sucking disc of the sharksuckers of the family Echeneidae is one of the most remarkable and most highly modified skeletal structures among vertebrates. We studied the development of the sucking disc based on a series of larval, juvenile, and adult echeneids ranging from 9.3 mm to 175 mm standard length. We revisited the question of the homology of the different skeletal parts that form the disc using an ontogenetic approach. We compared the initial stages of development of the disc with early developmental stages of the spinous dorsal fin in a representative of the morphologically basal percomorph Morone. We demonstrate that the “interneural rays” of echeneids are homologous with the proximal‐middle radials of Morone and other teleosts and that the “intercalary bones” of sharksuckers are homologous with the distal radials of Morone and other teleosts. The “intercalary bones” or distal radials develop a pair of large wing‐like lateral extensions in echeneids, not present in this form in any other teleost. Finally the “pectinated lamellae” are homologous with the fin spines of Morone and other acanthomorphs. The main part of each pectinated lamella is formed by bilateral extensions of the base of the fin spine just above its proximal tip, each of which develops a row of spinous projections, or spinules, along its posterior margin. The number of rows and the number of spinules increase with size, and they become autogenous from the body of the lamellae. We also provide a historical review of previous studies on the homology of the echeneid sucking disc and demonstrate that the most recent hypotheses, published in 2002, 2005 and 2006, are erroneous. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc. 相似文献
993.
New class I and II HLA alleles strongly associated with opposite patterns of progression to AIDS. 总被引:10,自引:0,他引:10
H Hendel S Caillat-Zucman H Lebuanec M Carrington S O'Brien J M Andrieu F Sch?chter D Zagury J Rappaport C Winkler G W Nelson J F Zagury 《Journal of immunology (Baltimore, Md. : 1950)》1999,162(11):6942-6946
The genetics of resistance to infection by HIV-1 cohort consists of 200 slow and 75 rapid progressors to AIDS corresponding to the extremes of HIV disease outcome of 20,000 Caucasians of European descent. A comprehensive analysis of HLA class I and class II genes in this highly informative cohort has identified HLA alleles associated with fast or slow progression, including several not described previously. A quantitative analysis shows an overall HLA influence independent of and equal in magnitude (for the protective effect) to the effect of the CCR5-Delta32 mutation. Among HLA class I genes, A29 (p = 0.001) and B22 (p < 0.0001) are significantly associated with rapid progression, whereas B14 (p = 0.001) and C8 (p = 0.004) are significantly associated with nonprogression. The class I alleles B27, B57, C14 (protective), and C16, as well as B35 (susceptible), are also influential, but their effects are less robust. Influence of class II alleles was only observed for DR11. These results confirm the influence of the immune system on disease progression and may have implications on peptide-based vaccine development. 相似文献
994.
Skin fibroblasts from Gardner syndrome (GS) compared with those from normal donors showed a significantly higher incidence of chromatid gaps and breaks following exposure to low-intensity, cool-white fluorescent light during G2 phase of the cell cycle. Considerable evidence supports the concept that chromatid gaps and breaks seen directly after exposure to DNA-damaging agents represent unrepaired DNA single- and double-strand breaks respectively. The changes in incidence of chromatid aberrations with time after light exposure are consistent with the sequence of events known to follow DNA damage and repair. Initially, the incidence of light-induced chromatid gaps was equivalent in GS and normal fibroblasts. In the normal cells, the chromatid gaps disappeared by 1 h post-exposure, presumably as a result of efficient repair of DNA single-strand breaks. In contrast, the incidence of gaps increased in GS cells by 0.5 h followed by a decrease at 1 h and concomitant increase in chromatid breaks. It appears from these findings that the increased incidence of chromatid damage in GS fibroblasts results from deficient repair of DNA single-strand breaks which arise from incomplete nucleotide excision of DNA damage during G2 phase. 相似文献
995.
996.
997.
998.
The effects of various anionic phospholipids on the in vitro assembly of MAP2/tubulin microtubules has been examined. We show that the potency to inhibit is related to the polarity of the phospholipids and that this is consistent with a mode of action involving the sequencing of microtubule-associated proteins (MAPs) by nonspecific electrostatic interactions. The inhibitory potency of phosphatidylinositol (PI) is, however, considerably larger than predicted by this model. The effects of PI on MAP2/tubulin microtubule assembly have therefore been examined in greater detail by preparing phosphatidylcholine (PC) liposomes doped with increasing amounts of PI. We show that when the PI is sufficiently dispersed by dilution with PC, it inhibits microtubule assembly by binding to MAP2 with an apparent stoichiometry, after correction for the bilamellar nature of the liposomes, of 1:1 mol.mol-1 PI:MAP2. Furthermore, we show that the Kd of this interaction is in the submicromolar range. 相似文献
999.
D I Medvedev I I Babichenko I Z Eremina A I Kravtsova 《Biulleten' eksperimental'no? biologii i meditsiny》1985,100(12):751-754
Electron microscopy of mouse neocortex was carried out during rehabilitation following long-term protein-caloric deficiency. Food rehabilitation led to partial recovery of brain ultrastructure, however, a high neuronal level of secondary lysosoms and lipofuscin bodies was preserved, with the changes in the spine apparatus and synaptic contacts persisting in neuropile. Carnitine addition to food during rehabilitation increased the number of free ribosomes in cortical neurons. A substantial development of granular endoplasmic reticulum was observed. A greater number of spine apparatus cisterns was detected, however, like in conventional rehabilitation, the width of synaptic clefts and postsynaptic densities remained narrower than in control mice. 相似文献
1000.
S N Ayrapetyan G Y Rychkov M A Suleymanyan 《Comparative biochemistry and physiology. A, Comparative physiology》1988,89(2):179-186
1. The effects of water flow through the membrane produced by an osmotic gradient on the ionic currents in Helix neurons and in squid giant axons were studied. 2. Outward water flow had a marked effect on the ionic currents. 3. Cell volume diminution in hypertonic solution was accompanied by a decrease in the number of functioning ionic channels in the neurons. 4. Decrease of the tonicity of the external 10(-8) M TTX-containing solution leads to a transient recovery of the action potentials of the squid. 相似文献