scholarly journals Basal versus apical dendritic long-term potentiation of commissural afferents to hippocampal CA1: a current-source density study

1993 ◽  
Vol 13 (6) ◽  
pp. 2391-2404 ◽  
Author(s):  
T Kaibara ◽  
LS Leung
Keyword(s):  
Current Source ◽  
Long Term Potentiation ◽  
Current Source Density ◽  
Source Density ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Density Study ◽  
A Current

scholarly journals Auditory Target and Novelty Processing in Patients with Unilateral Hippocampal Sclerosis: A Current-Source Density Study

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Adrià Vilà-Balló ◽  
Clément François ◽  
David Cucurell ◽  
Júlia Miró ◽  
Mercè Falip ◽  
...  
Keyword(s):  
Hippocampal Sclerosis ◽  
Current Source ◽  
Current Source Density ◽  
Auditory Target ◽  
Source Density ◽  
Novelty Processing ◽  
Density Study ◽  
A Current

Spatial overlap between populations of synapses determines the extent of their associative interaction during the induction of long-term potentiation and depression

1990 ◽  
Vol 64 (4) ◽  
pp. 1186-1198 ◽  
Author(s):  
G. White ◽  
W. B. Levy ◽  
O. Steward
Keyword(s):  
Current Source ◽  
Long Term Potentiation ◽  
Field Potentials ◽  
Conditioning Stimulation ◽  
Long Term Depression ◽  
Source Density ◽  
Topographical Organization ◽  
Term Potentiation ◽  
Recording Electrodes

1. This study evaluates the associative interactions between inputs that lead to long-term potentiation (LTP) and long-term depression (LTD) in the dentate gyrus (DG). Previous studies have revealed that when two inputs are coconditioned, the extent of LTP is greater than when each input is conditioned alone. Moreover, for a weak input that does not show LTP when conditioned alone, LTP can be induced in that weak input if it is coconditioned with a strong input. LTD results when one input is silent when another is conditioned. In the present study, we evaluate whether these associative interactions depend on the extent of overlap of the terminal fields of the different inputs. 2. The experiment took advantage of the topographical organization of the temporodentate pathway from the entorhinal cortex (EC) to the DG. Four stimulating electrodes were placed so as to activate ipsilateral and crossed components of the projections from medial and lateral portions of the EC. Recording electrodes were positioned unilaterally in the DG so as to record field potentials. The localization of the synaptic field that was activated by each electrode was determined by current source density (CSD) analysis. The extent of overlap between the terminal fields of ipsi- and contralateral pathways was assessed, and the pathways were divided into groups where the overlap between current sinks was 0-50 or 51-100%. 3. Conditioning stimulation (400-Hz trains of 8 pulses delivered 8 times) was delivered to pathways alone or in combination with other pathways. The extent of LTP was evaluated after coactivation of pathways that overlapped substantially (51-100%) or minimally (0-50%). The extent of LTD was evaluated in pathways that were silent during conditioning of other overlapping or nonoverlapping pathways. 4. The extent of associative LTP or LTD depended on the extent of overlap between the terminal fields of pathways. Coactivation of two pathways that overlapped by 51-100% led to LTP; coactivation of pathways that overlapped by 0-50% did not. Moreover, LTD was induced in a crossed pathway when an ipsilateral pathway that overlapped by 51-100% was activated, but not when a nonoverlapping (0-50% overlap) ipsilateral pathway was activated. The degree of associative LTP or LTD that was induced in crossed pathways was correlated with the percent overlap with the terminal field of the active ipsilateral pathway. 5. Evaluation of whether LTD was induced when one division (medial or lateral) of the ipsilateral pathway was silent when the other division was conditioned revealed similar relationships.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals An Endogenous RNA Transcript Antisense to CNGα1 Cation Channel mRNA

2002 ◽  
Vol 13 (10) ◽  
pp. 3696-3705 ◽  
Author(s):  
Chin-Hung Cheng ◽  
David Tai-Wai Yew ◽  
Hiu-Yee Kwan ◽  
Qing Zhou ◽  
Yu Huang ◽  
...  
Keyword(s):  
Expression System ◽  
Expression Patterns ◽  
Long Term Potentiation ◽  
Information Storage ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Oocyte Expression System ◽  
Neuronal Functions ◽  
Rna Transcript

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.

scholarly journals PKA drives an increase in AMPA receptor unitary conductance during LTP in the hippocampus

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pojeong Park ◽  
John Georgiou ◽  
Thomas M. Sanderson ◽  
Kwang-Hee Ko ◽  
Heather Kang ◽  
...  
Keyword(s):  
Ampa Receptors ◽  
Single Channel ◽  
Hippocampal Slices ◽  
Long Term Potentiation ◽  
Theta Burst Stimulation ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Necessary And Sufficient ◽  
Theta Burst

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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