Enhancement of Hippocampal Long-Term Potentiation in Vitro by Fucosyl-Carbohydrates

1997 ◽  
pp. 905-908 ◽  
Author(s):  
H. Matthies ◽  
S. Staak ◽  
K. H. Smalla ◽  
M. Krug
2016 ◽  
Vol 27 (8) ◽  
pp. 849-855 ◽  
Author(s):  
Nickolay K. Isaev ◽  
Elena V. Stelmashook ◽  
Elisaveta E. Genrikhs ◽  
Galina A. Korshunova ◽  
Natalya V. Sumbatyan ◽  
...  

AbstractIn 2008, using a model of compression brain ischemia, we presented the first evidence that mitochondria-targeted antioxidants of the SkQ family, i.e. SkQR1 [10-(6′-plastoquinonyl)decylrhodamine], have a neuroprotective action. It was shown that intraperitoneal injections of SkQR1 (0.5–1 μmol/kg) 1 day before ischemia significantly decreased the damaged brain area. Later, we studied in more detail the anti-ischemic action of this antioxidant in a model of experimental focal ischemia provoked by unilateral intravascular occlusion of the middle cerebral artery. The neuroprotective action of SkQ family compounds (SkQR1, SkQ1, SkQTR1, SkQT1) was manifested through the decrease in trauma-induced neurological deficit in animals and prevention of amyloid-β-induced impairment of long-term potentiation in rat hippocampal slices. At present, most neurophysiologists suppose that long-term potentiation underlies cellular mechanisms of memory and learning. They consider inhibition of this process by amyloid-β1-42as anin vitromodel of memory disturbance in Alzheimer’s disease. Further development of the above studies revealed that mitochondria-targeted antioxidants could retard accumulation of hyperphosphorylated τ-protein, as well as amyloid-β1-42, and its precursor APP in the brain, which are involved in developing neurodegenerative processes in Alzheimer’s disease.


2004 ◽  
Vol 370 (2-3) ◽  
pp. 155-159 ◽  
Author(s):  
Tatsuhiro Akaishi ◽  
Ken Nakazawa ◽  
Kaoru Sato ◽  
Yasuo Ohno ◽  
Yoshihisa Ito

1993 ◽  
Vol 69 (5) ◽  
pp. 1774-1778 ◽  
Author(s):  
V. Crepel ◽  
C. Hammond ◽  
K. Krnjevic ◽  
P. Chinestra ◽  
Y. Ben-Ari

1. The effects of an anoxic-aglycemic episode (1-3 min) on the pharmacologically isolated N-methyl-D-aspartate (NMDA)-mediated responses were examined in CA1 pyramidal hippocampal neurons in vitro. 2. An anoxic-aglycemic episode induced a long term potentiation (LTP) of the NMDA receptor-mediated field excitatory post-synoptic potentials (EPSPs). This LTP, referred to as anoxic LTP, was observed in the presence of 1) a normal Mg2+ concentration [+40.1 +/- 5% (mean +/- SE)], 2) a low Mg2+ concentration (+52.2 +/- 10%), or 3) a Mg2+ free (+49 +/- 11%), 1 h after anoxia. 3. Bath application of D-2-amino-5-phosphonovaleric acid (D-APV, 20 microM, 15-21 min) before, during, and after the anoxic-aglycemic episode, which transiently blocked the synaptic NMDA receptor mediated response, prevented the induction of anoxic LTP. 4. The intracellularly recorded NMDA receptor-mediated EPSP was also persistently potentiated by anoxia-aglycemia (+47 +/- 4%). This potentiation was not associated with changes in membrane potential or input resistance. 5. These findings provide the first evidence that an anoxic-aglycemic episode induces an LTP of NMDA receptor-mediated responses. This potentiation may participate in the cascade of events that lead to delayed neuronal death.


1993 ◽  
Vol 70 (3) ◽  
pp. 1255-1259 ◽  
Author(s):  
A. V. Nowicky ◽  
L. J. Bindman

1. Nitric oxide has been implicated in the production of long-term depression (LTD) in the cerebellum and in the production of long-term potentiation (LTP) and LTD in the hippocampus. We now provide evidence of its involvement in the induction of long-term synaptic potentiation in in vitro slices in the cerebral cortex of the rat. 2. Intracellular recordings were made from layer V neurons in the medial frontal cortex, and excitatory synaptic potentials (EPSPs) were evoked by electrical stimulation of layers II/III. Tetanic stimulation of this pathway may induce LTD or LTP or no change at these synapses. First we established experimental conditions under which a long lasting potentiation could be induced with a high incidence (> 60%), namely perfusion of slices with 1 microM bicuculline methiodide, second the use of increased shock duration in the tetanic conditioning stimuli, third and most important the addition of QX-314 to the microelectrode to reduce potassium conductances. Because the potentiation of the mean EPSP slope was significantly greater than the control at 40-min postconditioning, but was declining throughout this period, we refer to it for brevity as LTP, but strictly class it as an LTP-like phenomenon. 3. The nitric oxide (NO) synthase inhibitor interfered with the production of LTP. In the control group of neurons (n = 13) the mean depolarizing slope of the EPSP at 30-min post-conditioning was 142.7 +/- 2% (mean +/- SE) of the prestimulation control.(ABSTRACT TRUNCATED AT 250 WORDS)


1997 ◽  
Vol 78 (5) ◽  
pp. 2569-2573 ◽  
Author(s):  
Yue Wang ◽  
Jianqun Wu ◽  
Michael J. Rowan ◽  
Roger Anwyl

Wang, Yue, Jianqun Wu, Michael J. Rowan, and Roger Anwyl. Conditions for the induction of long-term potentiation and long-term depression by conjunctive pairing in the dentate gyrus in vitro. J. Neurophysiol. 78: 2569–2573, 1997. The conditions under which long-term potentiation (LTP) and long-term depression (LTD) of excitatory postsynaptic currents were induced by the conjunctive pairing-type protocol of afferent stimulation and postsynaptic depolarization were studied in the medial perforant pathway-granule cell synapse of the dentate gyrus in vitro. The conjunctive pairing of 1-Hz afferent stimulation and steady state postsynaptic depolarization to 0 mV did not induce LTP or LTD. Inhibition of LTD induction with a phosphatase inhibitor or ruthenium red resulted in induction of LTP after the conjunctive pairing. Such LTP induction was N-methyl-d-aspartate dependent. Conversely, inhibition of LTP induction with a kinase inhibitor resulted in LTD induction after the conjunctive pairing. Thus the failure to induce LTP or LTD with the pairing protocol involving depolarization to 0 mV membrane potential was due to simultaneous activation of intracellular processes that generate the induction of LTP and LTD. Increasing the frequency of afferent stimulation to 200 Hz, even for just eight stimuli, resulted in LTP induction. The studies show that two factors govern the induction of LTP/LTD, membrane potential and frequency of afferent stimulation, with either increased depolarization or increased afferent stimulation favoring LTP induction.


2009 ◽  
Vol 102 (6) ◽  
pp. 3082-3090 ◽  
Author(s):  
Jokūbas Žiburkus ◽  
Emily K. Dilger ◽  
Fu-Sun Lo ◽  
William Guido

The purpose of the present study was to determine whether retinal activity can support long-term changes in synaptic strength in the developing dorsal lateral geniculate nucleus (LGN) of thalamus. To test for this we made use of a rodent in vitro explant preparation in which retinal afferents and the intrinsic circuitry of the LGN remain intact. We repetitively stimulated the optic tract with a tetanus protocol that approximated the temporal features of spontaneous retinal waves. We found the amplitude of extracellular field potentials evoked by retinal stimulation changed significantly after tetanus and that the polarity of these alterations was related to postnatal age. At a time when substantial pruning of retinal connections occurs (postnatal day 1 [P1] to P14), high-frequency stimulation led to an immediate and long-term depression (LTD). However, at times when pruning wanes and adultlike patterns of connectivity are stabilizing (P16 to P30), the identical form of stimulation produced a modest form of potentiation (long-term potentiation [LTP]). The LTD was unaffected by the bath application of γ-aminobutyric acid type A and N-methyl-d-aspartate receptor antagonists. However, both LTD and LTP were blocked by L-type Ca2+-channel antagonists. Thus the Ca2+ influx associated with L-type channel activation mediates the induction of synaptic plasticity and may signal the pruning and subsequent stabilization of developing retinogeniculate connections.


2014 ◽  
Vol 10 ◽  
pp. P926-P926
Author(s):  
Christopher G. Parsons ◽  
Ross David Jeggo ◽  
Lydia Staniaszek ◽  
David Spanswick ◽  
Gerhard Rammes

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