Hippocampal lateralization and synaptic plasticity in the intact rat: no left-right asymmetry in electrically induced CA3-CA1 long-term potentiation

Stephen J. Martin (Lead / Corresponding author), Kate L. Shires, Bruno M. da Silva

Research output: Contribution to journalArticle

3 Citations (Scopus)
90 Downloads (Pure)

Abstract

The hippocampus is not a unitary, homogeneous brain area. Anatomical and functional specialization is evident along the septotemporal axis of the structure, and between the left and right hemispheres. In the mouse brain, a left-right asymmetry has been discovered in the plasticity of CA3-CA1 projections originating in the left versus right hippocampus. Presynaptic afferents originating in the left hemisphere-including both uncrossed Schaffer collaterals, and crossed commissural projections to the contralateral CA1-form small, plastic synapses, whereas afferents originating in right CA3 contact larger, less plastic, synapses. Studies using optogenetic techniques to selectively activate fibers originating from one hemisphere in ex vivo slices have revealed that projections originating from left CA3 exhibit a far greater capacity for long-term potentiation (LTP) of synaptic strength than those originating on the right. However, corresponding data from rats are currently unavailable, leaving open the question of species differences in hippocampal symmetry. In the current study, we reanalyzed data from our previous in vivo LTP work to address this issue. We analyzed plasticity in independent Schaffer collateral and commissural projections to CA1 originating from left and right CA3 in male Lister-hooded rats. However, we found no differences in the magnitude and duration of LTP induced in either crossed or uncrossed pathways following high-frequency tetanization of left versus right CA3. This contrast with previous findings may stem from methodological differences between in vivo electrical and ex vivo optogenetic approaches, but may reflect a genuine species difference in the organization and laterality of the rodent CA3-CA1 system.

Original languageEnglish
Pages (from-to)147-158
Number of pages12
JournalNeuroscience
Volume397
Early online date2 Dec 2018
DOIs
Publication statusPublished - 15 Jan 2019

Fingerprint

Neuronal Plasticity
Long-Term Potentiation
Hippocampus
Optogenetics
Synapses
Plastics
Brain
Rodentia

Keywords

  • hippocampus
  • LTP
  • synaptic plasticity
  • Schaffer collateral
  • commissural
  • in vivo

Cite this

@article{eba857344375470aa0cd00a4a4fcee0a,
title = "Hippocampal lateralization and synaptic plasticity in the intact rat: no left-right asymmetry in electrically induced CA3-CA1 long-term potentiation",
abstract = "The hippocampus is not a unitary, homogeneous brain area. Anatomical and functional specialization is evident along the septotemporal axis of the structure, and between the left and right hemispheres. In the mouse brain, a left-right asymmetry has been discovered in the plasticity of CA3-CA1 projections originating in the left versus right hippocampus. Presynaptic afferents originating in the left hemisphere-including both uncrossed Schaffer collaterals, and crossed commissural projections to the contralateral CA1-form small, plastic synapses, whereas afferents originating in right CA3 contact larger, less plastic, synapses. Studies using optogenetic techniques to selectively activate fibers originating from one hemisphere in ex vivo slices have revealed that projections originating from left CA3 exhibit a far greater capacity for long-term potentiation (LTP) of synaptic strength than those originating on the right. However, corresponding data from rats are currently unavailable, leaving open the question of species differences in hippocampal symmetry. In the current study, we reanalyzed data from our previous in vivo LTP work to address this issue. We analyzed plasticity in independent Schaffer collateral and commissural projections to CA1 originating from left and right CA3 in male Lister-hooded rats. However, we found no differences in the magnitude and duration of LTP induced in either crossed or uncrossed pathways following high-frequency tetanization of left versus right CA3. This contrast with previous findings may stem from methodological differences between in vivo electrical and ex vivo optogenetic approaches, but may reflect a genuine species difference in the organization and laterality of the rodent CA3-CA1 system.",
keywords = "hippocampus, LTP, synaptic plasticity, Schaffer collateral, commissural, in vivo",
author = "Martin, {Stephen J.} and Shires, {Kate L.} and {da Silva}, {Bruno M.}",
note = "This work was supported by a Wellcome Trust Project Grant (WT083601MA) and a Tenovus Scotland Major Research Grant (T14/11), both held by SJM.",
year = "2019",
month = "1",
day = "15",
doi = "10.1016/j.neuroscience.2018.11.044",
language = "English",
volume = "397",
pages = "147--158",
journal = "Neuroscience",
issn = "0306-4522",
publisher = "Elsevier",

}

TY - JOUR

T1 - Hippocampal lateralization and synaptic plasticity in the intact rat

T2 - no left-right asymmetry in electrically induced CA3-CA1 long-term potentiation

AU - Martin, Stephen J.

AU - Shires, Kate L.

AU - da Silva, Bruno M.

N1 - This work was supported by a Wellcome Trust Project Grant (WT083601MA) and a Tenovus Scotland Major Research Grant (T14/11), both held by SJM.

PY - 2019/1/15

Y1 - 2019/1/15

N2 - The hippocampus is not a unitary, homogeneous brain area. Anatomical and functional specialization is evident along the septotemporal axis of the structure, and between the left and right hemispheres. In the mouse brain, a left-right asymmetry has been discovered in the plasticity of CA3-CA1 projections originating in the left versus right hippocampus. Presynaptic afferents originating in the left hemisphere-including both uncrossed Schaffer collaterals, and crossed commissural projections to the contralateral CA1-form small, plastic synapses, whereas afferents originating in right CA3 contact larger, less plastic, synapses. Studies using optogenetic techniques to selectively activate fibers originating from one hemisphere in ex vivo slices have revealed that projections originating from left CA3 exhibit a far greater capacity for long-term potentiation (LTP) of synaptic strength than those originating on the right. However, corresponding data from rats are currently unavailable, leaving open the question of species differences in hippocampal symmetry. In the current study, we reanalyzed data from our previous in vivo LTP work to address this issue. We analyzed plasticity in independent Schaffer collateral and commissural projections to CA1 originating from left and right CA3 in male Lister-hooded rats. However, we found no differences in the magnitude and duration of LTP induced in either crossed or uncrossed pathways following high-frequency tetanization of left versus right CA3. This contrast with previous findings may stem from methodological differences between in vivo electrical and ex vivo optogenetic approaches, but may reflect a genuine species difference in the organization and laterality of the rodent CA3-CA1 system.

AB - The hippocampus is not a unitary, homogeneous brain area. Anatomical and functional specialization is evident along the septotemporal axis of the structure, and between the left and right hemispheres. In the mouse brain, a left-right asymmetry has been discovered in the plasticity of CA3-CA1 projections originating in the left versus right hippocampus. Presynaptic afferents originating in the left hemisphere-including both uncrossed Schaffer collaterals, and crossed commissural projections to the contralateral CA1-form small, plastic synapses, whereas afferents originating in right CA3 contact larger, less plastic, synapses. Studies using optogenetic techniques to selectively activate fibers originating from one hemisphere in ex vivo slices have revealed that projections originating from left CA3 exhibit a far greater capacity for long-term potentiation (LTP) of synaptic strength than those originating on the right. However, corresponding data from rats are currently unavailable, leaving open the question of species differences in hippocampal symmetry. In the current study, we reanalyzed data from our previous in vivo LTP work to address this issue. We analyzed plasticity in independent Schaffer collateral and commissural projections to CA1 originating from left and right CA3 in male Lister-hooded rats. However, we found no differences in the magnitude and duration of LTP induced in either crossed or uncrossed pathways following high-frequency tetanization of left versus right CA3. This contrast with previous findings may stem from methodological differences between in vivo electrical and ex vivo optogenetic approaches, but may reflect a genuine species difference in the organization and laterality of the rodent CA3-CA1 system.

KW - hippocampus

KW - LTP

KW - synaptic plasticity

KW - Schaffer collateral

KW - commissural

KW - in vivo

U2 - 10.1016/j.neuroscience.2018.11.044

DO - 10.1016/j.neuroscience.2018.11.044

M3 - Article

C2 - 30513373

VL - 397

SP - 147

EP - 158

JO - Neuroscience

JF - Neuroscience

SN - 0306-4522

ER -