Effects of Ethanol on Synaptic Plasticity and NMDA Currents in the Juvenile Rat Dentate Gyrus.

Content Provider	Europe PMC
Author	Sawchuk, Scott D. Reid, Hannah M.O. Neale, Katie J. Shin, James Christie, Brian R.
Editor	Nixon, Kimberly
Copyright Year	2020
Abstract	Background and Objectives: We examined how acute ethanol (EtOH) exposure affects long term depression (LTD) in the dentate gyrus (DG) of the hippocampus in juvenile rats. EtOH is thought to directly modulate n-methyl-D-aspartate receptor (NMDAr) currents, which are believed important for LTD induction. LTD in turn is believed to play an important developmental role in the hippocampus by facilitating synaptic pruning. Methods: Hippocampal slices (350μm) were obtained at post-natal day (PND) 14, 21, or 28. Field EPSPs (excitatory post-synaptic potential) or whole-cell EPSCs (excitatory post-synaptic conductance) were recorded from the DG (dentate gyrus) in response to medial perforant path activation. Low-frequency stimulation (LFS; 900 pulses; 120 s pulse) was used to induce LTD. Results: Whole-cell recordings indicated that EtOH exposure at 50mM did not significantly impact ensemble NMDAr EPSCs in slices obtained from animals in the PND14 or 21 groups, but it reliably produced a modest inhibition in the PND28 group. Increasing the concentration to 100 mM resulted in a modest inhibition of NMDAr EPSCs in all three groups. LTD induction and maintenance was equivalent in magnitude in all three age groups in control conditions, however, and surprisingly, NMDA antagonist AP5 only reliably blocked LTD in the PND21 and 28 age groups. The application of 50 mM EtOH attenuated LTD in all three age groups, however increasing the concentration to 100 mM did not reliably inhibit LTD. Conclusions: These results indicate that the effect of EtOH on NMDAr-EPSCs recorded from DGCs is both age and concentration dependent in juveniles. Low concentrations of EtOH can attenuate, but did not block LTD in the DG. The effects of EtOH on LTD do not align well with it’s effects on NNMDA receptors.
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ISSN	22136304
Volume Number	6
PubMed Central reference number	PMC7903019
Issue Number	1
PubMed reference number	33680851
Journal	Brain Plasticity [Brain Plast]
e-ISSN	22136312
DOI	10.3233/bpl-200110
Language	English
Publisher	IOS Press
Publisher Date	2020-12-29
Publisher Place	The Netherlands
Access Restriction	Open
Rights License	This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial (CC BY-NC 4.0) License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2020 – IOS Press and the authors. All rights reserved
Subject Keyword	Ethanol dentate gyrus hippocampus long-term depression NMDA n-methyl-D-aspartate
Content Type	Text
Resource Type	Article
Subject	Neuroscience Psychology