| 12770 |
Creator |
7886d8a8c9204366c84d0d91a5a53953 |
| 12770 |
Creator |
ext-5fdf72b00ea4e97d3abc2141ce434dac |
| 12770 |
Creator |
ext-6b3f631d6d0c8501e2b1e9909802bde9 |
| 12770 |
Creator |
ext-a777781e9f6656bb1e8840622f08fad1 |
| 12770 |
Date |
2004 |
| 12770 |
Is Part Of |
p0953816X |
| 12770 |
Is Part Of |
repository |
| 12770 |
abstract |
Mechanisms of expression of long-term synaptic plasticity are believed to involve
morphological changes of the activated synapses and remodelling of connectivity. Here,
we investigated changes in synaptic and neuronal parameters in the dentate gyrus 24
h after induction of long-term potentiation (LTP) and long-term depression (LTD) in
awake rats. In dentate granule cells, tetanization of the medial or lateral perforant
paths induces LTP in specific synaptic bands along the dendrites in the middle and
outer molecular layers, respectively, and tetanization of the lateral path induces
robust LTD heterosynaptically in the middle molecular layer. This functional segregation
allowed us to assess morphological changes associated with LTP and LTD in each pathway
in the same population of neurons. Electron microscopy and unbiased counting methods
were used to estimate neuronal density, axospinous, axodendritic and perforated synapse
density, multiple synapse bouton density and postsynaptic density (PSD) area. Whereas
there was no change in neuronal density, PSD area and multiple synapse boutons 24
h after either LTP or LTD, there was a noninput-specific increase in unperforated
axospinous synapses after both LTP and LTD. However, we found that LTP of the medial,
but not lateral, perforant path is associated with a specific increase in perforated
axospinous synapses in the potentiated area. We also show that heterosynaptic LTD
is associated with an input-specific increase in axodendritic synapse density. These
results suggest that each perforant pathway may differ with respect to the nature
of LTP-induced long-term changes and show that morphologically LTD is not simply the
converse of LTP. |
| 12770 |
authorList |
authors |
| 12770 |
issue |
8 |
| 12770 |
status |
peerReviewed |
| 12770 |
volume |
19 |
| 12770 |
type |
AcademicArticle |
| 12770 |
type |
Article |
| 12770 |
label |
Mezey, Szilvia; Doyere, Valérie; Souza, Ian De and Stewart, Michael (2004). Long-term
synaptic morphometry changes after induction of long-term potentiation and long-term
depression in the dentate gyrus of awake rats are not simply mirror phenomena. European
Journal of Neuroscience, 19(8) pp. 2310–2318. |
| 12770 |
label |
Mezey, Szilvia; Doyere, Valérie; Souza, Ian De and Stewart, Michael (2004). Long-term
synaptic morphometry changes after induction of long-term potentiation and long-term
depression in the dentate gyrus of awake rats are not simply mirror phenomena. European
Journal of Neuroscience, 19(8) pp. 2310–2318. |
| 12770 |
Title |
Long-term synaptic morphometry changes after induction of long-term potentiation and
long-term depression in the dentate gyrus of awake rats are not simply mirror phenomena |
| 12770 |
in dataset |
oro |