Long-term potentiation in the prefrontal cortex following stimulation of the hippocampal CA1/subicular region

1990 ◽  
Vol 114 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Serge Laroche ◽  
Thérèse M. Jay ◽  
Anne-Marie Thierry
2001 ◽  
Vol 305 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Yoshinori Izaki ◽  
Masatoshi Takita ◽  
Thérèse M Jay ◽  
Hidekazu Kaneko ◽  
Shinya S Suzuki ◽  
...  

2013 ◽  
Vol 16 (5) ◽  
pp. 1165-1167 ◽  
Author(s):  
Haowei Shen ◽  
Peter W. Kalivas

Abstract Addiction changes prefrontal cortex regulation of the nucleus accumbens, including reduced ability to induce long-term potentiation (LTP) and long-term depression (LTD). This important potential mechanism of impaired prefrontal regulation of behaviour has been shown only for cocaine. Here we show that animals trained to self-administer heroin demonstrate impaired LTP and LTD in the core of the nucleus accumbens following in vivo stimulation of the prelimbic prefrontal cortex. These data indicate that compromised synaptic plasticity in prefrontal to accumbens projections is a common feature of at least two distinct classes of addictive drug.


2001 ◽  
Vol 85 (1) ◽  
pp. 399-406 ◽  
Author(s):  
R. J. Cormier ◽  
A. C. Greenwood ◽  
J. A. Connor

The magnitude of postsynaptic Ca2+ transients is thought to affect activity-dependent synaptic plasticity associated with learning and memory. Large Ca2+ transients have been implicated in the induction of long-term potentiation (LTP), while smaller Ca2+ transients have been associated with long-term depression (LTD). However, a direct relationship has not been demonstrated between Ca2+ measurements and direction of synaptic plasticity in the same cells, using one induction protocol. Here, we used glutamate iontophoresis to induce Ca2+ transients in hippocampal CA1 neurons injected with the Ca2+-indicator fura-2. Test stimulation of one or two synaptic pathways before and after iontophoresis showed that the direction of synaptic plasticity correlated with glutamate-induced Ca2+ levels above a threshold, below which no plasticity occurred (∼180 nM). Relatively low Ca2+ levels (180–500 nM) typically led to LTD of synaptic transmission and higher levels (>500 nM) often led to LTP. Failure to show plasticity correlated with Ca2+ levels in two distinct ranges: <180 nM and ∼450–600 nM, while only LTD occurred between these ranges. Our data support a class of models in which failure of Ca2+ transients to affect transmission may arise either from insufficient Ca2+ to affect Ca2+-sensitive proteins regulating synaptic strength through opposing activities or from higher Ca2+ levels that reset activities of such proteins without affecting the net balance of activities. Our estimates of the threshold Ca2+ level for LTD (∼180 nM) and for the transition from LTD to LTP (∼540 nM) may assist in constraining the molecular details of such models.


1991 ◽  
Vol 65 (1) ◽  
pp. 20-32 ◽  
Author(s):  
Y. Komatsu ◽  
S. Nakajima ◽  
K. Toyama

1. Intracellular recording was made from layer II-III cells in slice preparations of kitten (30-40 days old) visual cortex. Low-frequency (0.1 Hz) stimulation of white matter (WM) usually evoked an excitatory postsynaptic potential (EPSP) followed by an inhibitory postsynaptic potential (IPSP). The postsynaptic potentials (PSPs) showed strong dependence on stimulus frequency. Early component of EPSP and IPSP evoked by weak stimulation both decreased monotonically at frequencies greater than 0.5-1 Hz. Strong stimulation similarly depressed the early EPSP at higher frequencies (greater than 2 Hz) and replaced the IPSP with a late EPSP, which had a maximum amplitude in the stimulus frequency range of 2-5 Hz. 2. Very weak WM stimulation sometimes evoked EPSPs in isolation from IPSPs. The falling phase of the EPSP revealed voltage dependence characteristic to the responses mediated by N-methyl-D-aspartate (NMDA) receptors and was depressed by application of an NMDA antagonist DL-2-amino-5-phosphonovalerate (APV), whereas the rising phase of the EPSP was insensitive to APV. 3. The early EPSPs followed by IPSPs were insensitive to APV but were replaced with a slow depolarizing potential by application of a non-NMDA antagonist 6,7-dinitro-quinoxaline-2,3-dione (DNQX), indicating that the early EPSP is mediated by non-NMDA receptors. The slow depolarization was mediated by NMDA receptors because it was depressed by membrane hyperpolarization or addition of APV. 4. The late EPSP evoked by higher-frequency stimulation was abolished by APV, indicating that it is mediated by NMDA receptors, which are located either on the recorded cell or on presynaptic cells to the recorded cells. 5. Long-term potentiation (LTP) of EPSPs was examined in cells perfused with solutions containing 1 microM bicuculline methiodide (BIM), a gamma-aminobutyric acid (GABA) antagonist. WM was stimulated at 2 Hz for 15 min as a conditioning stimulus to induce LTP, and the resultant changes were tested by low-frequency (0.1 Hz) stimulation of WM. 6. LTP of early EPSPs occurred in more than one-half of the cells (8/13) after strong conditioning stimulation. The rising slope of the EPSP was increased 1.6 times on average. 7. To test involvement of NMDA receptors in the induction of LTP in the early EPSP, the effect of conditioning stimulation was studied in a solution containing 100 microM APV, which was sufficient to block completely synaptic transmission mediated by NMDA receptors. LTP occurred in the same frequency and magnitude as in control solution.


2002 ◽  
Vol 13 (10) ◽  
pp. 3696-3705 ◽  
Author(s):  
Chin-Hung Cheng ◽  
David Tai-Wai Yew ◽  
Hiu-Yee Kwan ◽  
Qing Zhou ◽  
Yu Huang ◽  
...  

CNG channels are cyclic nucleotide-gated Ca2+-permeable channels that are suggested to be involved in the activity-dependent alterations of synaptic strength that are thought to underlie information storage in the CNS. In this study, we isolated an endogenous RNA transcript antisense to CNGα1 mRNA. This transcript was capable of down-regulating the expression of sense CNGα1 in theXenopus oocyte expression system. RT-PCR, Northern blot, and in situ hybridization analyses showed that the transcript was coexpressed with CNGα1 mRNA in many regions of human brain, notably in those regions that were involved in long-term potentiation and long-term depression, such as hippocampal CA1 and CA3, dentate gyrus, and cerebellar Purkinje layer. Comparison of expression patterns between adult and fetal cerebral cortex revealed that there were concurrent developmental changes in the expression levels of anti-CNG1 and CNGα1. Treatment of human glioma cell T98 with thyroid hormone T3 caused a significant increase in anti-CNG1 expression and a parallel decrease in sense CNGα1 expression. These data suggest that the suppression of CNGα1 expression by anti-CNG1 may play an important role in neuronal functions, especially in synaptic plasticity and cortical development. Endogenous antisense RNA-mediated regulation may represent a new mechanism through which the activity of ion channels can be regulated in the human CNS.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pojeong Park ◽  
John Georgiou ◽  
Thomas M. Sanderson ◽  
Kwang-Hee Ko ◽  
Heather Kang ◽  
...  

AbstractLong-term potentiation (LTP) at hippocampal CA1 synapses can be expressed by an increase either in the number (N) of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors or in their single channel conductance (γ). Here, we have established how these distinct synaptic processes contribute to the expression of LTP in hippocampal slices obtained from young adult rodents. LTP induced by compressed theta burst stimulation (TBS), with a 10 s inter-episode interval, involves purely an increase in N (LTPN). In contrast, either a spaced TBS, with a 10 min inter-episode interval, or a single TBS, delivered when PKA is activated, results in LTP that is associated with a transient increase in γ (LTPγ), caused by the insertion of calcium-permeable (CP)-AMPA receptors. Activation of CaMKII is necessary and sufficient for LTPN whilst PKA is additionally required for LTPγ. Thus, two mechanistically distinct forms of LTP co-exist at these synapses.


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