scholarly journals Selective Induction of LTP and LTD by Postsynaptic [Ca2+]i Elevation

1999 ◽  
Vol 81 (2) ◽  
pp. 781-787 ◽  
Author(s):  
Shao-Nian Yang ◽  
Yun-Gui Tang ◽  
Robert S. Zucker
Keyword(s):  
Calcium Concentration ◽  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Biological Information ◽  
Synaptic Modulation ◽  
Ca1 Pyramidal Cells ◽  
Caged Calcium ◽  
Term Potentiation ◽  
Calcium Compound

Selective Induction of LTP and LTD by Postsynaptic [Ca2+]i Elevation. Long-term potentiation (LTP) and long-term depression (LTD), two prominent forms of synaptic plasticity at glutamatergic afferents to CA1 hippocampal pyramidal cells, are both triggered by the elevation of postsynaptic intracellular calcium concentration ([Ca2+]i). To understand how one signaling molecule can be responsible for triggering two opposing forms of synaptic modulation, different postsynaptic [Ca2+]i elevation patterns were generated by a new caged calcium compound nitrophenyl-ethylene glycol-bis(β-aminoethyl ether)- N, N, N′, N′-tetraacetic acid in CA1 pyramidal cells. We found that specific patterns of [Ca2+]i elevation selectively activate LTP or LTD. In particular, only LTP was triggered by a brief increase of [Ca2+]i with relatively high magnitude, which mimics the [Ca2+]i rise during electrical stimulation typically used to induce LTP. In contrast, a prolonged modest rise of [Ca2+]i reliably induced LTD. An important implication of the results is that both the amplitude and the duration of an intracellular chemical signal can carry significant biological information.

scholarly journals Long-term potentiation at single fiber inputs to hippocampal CA1 pyramidal cells.

1996 ◽  
Vol 93 (16) ◽  
pp. 8710-8715 ◽  
Author(s):  
J. T. Isaac ◽  
G. O. Hjelmstad ◽  
R. A. Nicoll ◽  
R. C. Malenka
Keyword(s):  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Single Fiber ◽  
Ca1 Pyramidal Cells ◽  
Term Potentiation ◽  
Hippocampal Ca1

Long-term potentiation at the apical and basal dendritic synapses of CA1 after local stimulation in behaving rats

1995 ◽  
Vol 73 (5) ◽  
pp. 1938-1946 ◽  
Author(s):  
L. S. Leung ◽  
B. Shen
Keyword(s):  
High Frequency ◽  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Ca1 Pyramidal Cells ◽  
Stratum Oriens ◽  
Term Potentiation ◽  
Theta Frequency ◽  
Freely Behaving ◽  
Local Stimulation

1. We recorded the extracellular excitatory postsynaptic potentials (EPSPs) in CA1 in the freely behaving rats after stimulation of the apical dendritic and basal dendritic afferents. The apical dendritic population EPSP was negative at the apical dendritic layers and positive at stratum oriens and alveus. The basal dendritic population EPSP was negative at basal dendritic layer (stratum oriens) and positive at the cell body and apical dendritic layers. 2. We delivered various tetanic stimulus patterns in an attempt to elicit long-term potentiation (LTP) at the apical dendritic synapse of CA1 pyramidal cells. A 200-Hz high-frequency train (HF) 1 s in duration was more successful than theta-frequency primed bursts (PBs; 1 or 4 priming pulses followed by 10 or 4 pulses at 100 Hz) in eliciting LTP of the apical dendritic population EPSP, recorded either ipsilaterally or contralaterally. 3. Tetanus applied to the apical dendritic afferents occasionally elicited long-term depression (LTD) at an intensity lower than the LTP threshold. LTD persisted to > or = 1 day after a tetanus. 4. High-intensity tetanic stimulations often elicited hippocampal afterdischarges (ADs). If the AD duration was brief (< 15 s), apical dendritic LTP could follow the AD. However, if the AD duration was long, no apical dendritic LTP was observed. Tetanus that evoked an apical dendritic LTP typically evoked a short hippocampal AD < 15 s in duration. 5. LTP of the basal dendritic population EPSP was readily elicited either after an HF or a PB tetanus of low (1.5-2 times threshold) stimulus intensity.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Strong diffusional coupling between spines and dendrites promotes long-term potentiation of Schaffer collateral synapses

2018 ◽  
Author(s):  
Shuting Yin ◽  
Christian Schulze ◽  
Thomas G. Oertner
Keyword(s):  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Functional Change ◽  
Limiting Factor ◽  
Ca1 Pyramidal Cells ◽  
Two Photon ◽  
Paired Stimulation ◽  
Term Potentiation ◽  
Related Proteins

AbstractDendritic spines on CA1 pyramidal cells are highly variable in size and shape. For some spine synapses, long and narrow spine necks provide strong diffusional and electrical isolation from the main dendrite, and it has been speculated that synapses on well isolated spines could be more plastic than synapses on spines with low resistance necks. Here we test this hypothesis by first measuring the diffusional resistance of spine necks, then pairing two-photon glutamate uncaging with bursts of back-propagating action potentials. Paired stimulation induced significant (155%) long-term potentiation (LTP) of synapses on weakly isolated spines, but no net functional change of synapses on highly isolated spines. No correlation was found between spine head volume and functional plasticity of the synapses. We conclude that contrary to our expectations, diffusional isolation makes potentiation of synapses more difficult. Our results support the concept that delivery of plasticity-related proteins from the dendrite into the spine is a limiting factor for LTP.

scholarly journals Long-term potentiation at pyramidal cell to somatostatin interneuron synapses controls hippocampal network plasticity and memory

2021 ◽  
Author(s):  
Jean-Claude Lacaille ◽  
Azam Asgarihafshejani ◽  
Eve Honore ◽  
Francois-Xavier Michon ◽  
Isabel Laplante
Keyword(s):  
Pyramidal Cell ◽  
Memory Consolidation ◽  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Feedback Mechanism ◽  
Ca1 Pyramidal Cells ◽  
Term Potentiation ◽  
Hippocampal Network

Hippocampal somatostatin (SOM) cells are dendrite-projecting inhibitory interneurons. CA1 SOM cells receive major excitatory inputs from pyramidal cells (PC-SOM synapses) which show mGluR1a- and mTORC1-mediated long-term potentiation (LTP). PC-SOM synapse LTP contributes to CA1 network metaplasticity and memory consolidation, but whether it is sufficient to regulate these processes remains unknown. Here we used optogenetic stimulation of CA1 pyramidal cells and whole cell recordings in slices to show that optogenetic theta burst stimulation (TBSopto) produces LTP at PC-SOM synapses. At the network level, we found that TBSopto differentially regulates metaplasticity of pyramidal cell inputs: enhancing LTP at Schaffer collateral synapses and depressing LTP at temporo-ammonic synapses. At the behavioral level, we uncovered that in vivo TBSopto regulates learning-induced LTP at PC-SOM synapses, as well as contextual fear memory. Thus, LTP of PC-SOM synapses is a long-term feedback mechanism controlling pyramidal cell synaptic plasticity, sufficient to regulate memory consolidation.

Protein kinase C injection into hippocampal pyramidal cells elicits features of long term potentiation

Nature ◽  
1987 ◽  
Vol 328 (6129) ◽  
pp. 426-429 ◽  
Author(s):  
G.-Y. Hu ◽  
Ø. Hvalby ◽  
S. I. Walaas ◽  
K. A. Albert ◽  
P. Skjeflo ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Pyramidal Cells ◽  
Long Term Potentiation ◽  
Kinase C ◽  
Term Potentiation ◽  
Hippocampal Pyramidal Cells
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