scholarly journals High-Frequency Stimulation Induces Ethanol-Sensitive Long-Term Potentiation at Glutamatergic Synapses in the Dorsolateral Bed Nucleus of the Stria Terminalis

2004 ◽  
Vol 24 (25) ◽  
pp. 5741-5747 ◽  
Author(s):  
C. Weitlauf
Keyword(s):  
High Frequency ◽  
Long Term Potentiation ◽  
High Frequency Stimulation ◽  
Stria Terminalis ◽  
Glutamatergic Synapses ◽  
Bed Nucleus ◽  
Term Potentiation ◽  
Frequency Stimulation

scholarly journals Cholecystokinin release triggered by NMDA receptors produces LTP and sound–sound associative memory

2019 ◽  
Vol 116 (13) ◽  
pp. 6397-6406 ◽  
Author(s):  
Xi Chen ◽  
Xiao Li ◽  
Yin Ting Wong ◽  
Xuejiao Zheng ◽  
Haitao Wang ◽  
...  
Keyword(s):  
Associative Learning ◽  
Associative Memory ◽  
High Frequency ◽  
Low Frequency ◽  
Long Term Potentiation ◽  
High Frequency Stimulation ◽  
Low Frequency Stimulation ◽  
Term Potentiation ◽  
Frequency Stimulation

Memory is stored in neural networks via changes in synaptic strength mediated in part by NMDA receptor (NMDAR)-dependent long-term potentiation (LTP). Here we show that a cholecystokinin (CCK)-B receptor (CCKBR) antagonist blocks high-frequency stimulation-induced neocortical LTP, whereas local infusion of CCK induces LTP. CCK−/−mice lacked neocortical LTP and showed deficits in a cue–cue associative learning paradigm; and administration of CCK rescued associative learning deficits. High-frequency stimulation-induced neocortical LTP was completely blocked by either the NMDAR antagonist or the CCKBR antagonist, while application of either NMDA or CCK induced LTP after low-frequency stimulation. In the presence of CCK, LTP was still induced even after blockade of NMDARs. Local application of NMDA induced the release of CCK in the neocortex. These findings suggest that NMDARs control the release of CCK, which enables neocortical LTP and the formation of cue–cue associative memory.

scholarly journals Kainate receptors and the induction of mossy fibre long-term potentiation

2003 ◽  
Vol 358 (1432) ◽  
pp. 657-666 ◽  
Author(s):  
Zuner A. Bortolotto ◽  
Sari Lauri ◽  
John T. R. Isaac ◽  
Graham L. Collingridge
Keyword(s):  
Glutamate Receptors ◽  
High Frequency ◽  
Long Term Potentiation ◽  
Kainate Receptors ◽  
Kainate Receptor ◽  
High Frequency Stimulation ◽  
Mossy Fibre ◽  
Term Potentiation ◽  
Frequency Stimulation

There is intense interest in understanding the molecular mechanisms involved in long-term potentiation (LTP) in the hippocampus. Significant progress in our understanding of LTP has followed from studies of glutamate receptors, of which there are four main subtypes ( α -amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA), N -methyl-D-aspartate (NMDA), mGlu and kainate). This article summarizes the evidence that the kainate subtype of glutamate receptor is an important trigger for the induction of LTP at mossy fibre synapses in the CA3 region of the hippocampus. The pharmacology of the first selective kainate receptor antagonists, in particular the GLU K5 subunit selective antagonist LY382884, is described. LY382884 selectively blocks the induction of mossy fibre LTP, in response to a variety of different high-frequency stimulation protocols. This antagonist also inhibits the pronounced synaptic facilitation of mossy fibre transmission that occurs during high-frequency stimulation. These effects are attributed to the presence of presynaptic GLU K5 -subunit-containing kainate receptors at mossy fibre synapses. Differences in kainate receptor-dependent synaptic facilitation of AMPA and NMDA receptor-mediated synaptic transmission are described. These data are discussed in the context of earlier reports that glutamate receptors are not involved in mossy fibre LTP and more recent experiments using kainate receptor knockout mice, that argue for the involvement of GLU K6 but not GLU K5 kainate receptor subunits. We conclude that activation of presynaptic GLU K5 -containing kainate receptors is an important trigger for the induction of mossy fibre LTP in the hippocampus.

scholarly journals Low Doses of Fentanyl Block Central Sensitization in the Rat Spinal Cord In Vivo

2004 ◽  
Vol 100 (6) ◽  
pp. 1545-1551 ◽  
Author(s):  
Justus Benrath ◽  
Christina Brechtel ◽  
Eike Martin ◽  
Jürgen Sandkühler
Keyword(s):  
Spinal Cord ◽  
High Frequency ◽  
Long Term Potentiation ◽  
High Frequency Stimulation ◽  
Low Doses ◽  
Term Potentiation ◽  
C Fiber ◽  
Frequency Stimulation

Background mu-Opioid receptor agonists are strong analgesics. However, their usefulness for preemptive analgesia is controversial. The authors tested antinociceptive and preemptive properties of fentanyl as a mu-opioid receptor agonist in a model of spinal nociception in vivo. Methods C fiber-evoked potentials were recorded in the superficial laminae I-II of the rat lumbar spinal cord with glass microelectrodes in response to electrical stimulation of the sciatic nerve. High-frequency stimulation was applied on the sciatic nerve to induce long-term potentiation of C fiber-evoked field potentials, a form of central sensitization. To test the effect of fentanyl on acute nociception, fentanyl was infused intravenously at increasing doses (6-192 microg.kg(-1).h(-1)). One hour after start of infusion, high-frequency stimulation was applied to evaluate effects of fentanyl on the induction of long-term potentiation. Results In the absence of fentanyl, high-frequency stimulation potentiated C fiber-evoked field potentials to 149 +/-12% of controls (mean +/-SEM; n = 6) for at least 1 h. Increasing doses of fentanyl led to a significant reduction of C fiber-evoked potentials in a dose-dependent manner. The induction of long-term potentiation was blocked by low doses of fentanyl (infusion 12-48 microg.kg(1).h(-1)). At high doses, fentanyl did not block the induction of long-term potentiation (infusion 96-192 microg.kg(-1).h(-1)). Conclusions : Low doses of fentanyl block the synaptic form of central sensitization in the rat spinal cord in vivo, but higher doses do not have this effect.

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