Time-course and mechanisms of homeostatic plasticity in layers 2/3 and 5 of the barrel cortex

Abstract

Recent studies have shown that ocular dominance plasticity in layer 2/3 of the visual cortex exhibits a form of homeostatic plasticity that is related to synaptic scaling and depends on TNFα. In this study, we tested whether a similar form of plasticity was present in layer 2/3 of the barrel cortex and, therefore, whether the mechanism was likely to be a general property of cortical neurons. We found that whisker deprivation could induce homeostatic plasticity in layer 2/3 of barrel cortex, but not in a mouse strain lacking synaptic scaling. The time-course of homeostatic plasticity in layer 2/3 was similar to that of L5 regular spiking (RS) neurons (L5RS), but slower than that of L5 intrinsic bursting (IB) neurons (L5IB). In layer 5, the strength of evoked whisker responses and ex vivo miniature excitatory post-synaptic currents (mEPSCs) amplitudes showed an identical time-course for homeostatic plasticity, implying that plasticity at excitatory synapses contacting layer 5 neurons is sufficient to explain the changes in evoked responses. Spontaneous firing rate also showed homeostatic behaviour for L5IB cells, but was absent for L5RS cells over the time-course studied. Spontaneous firing rate homeostasis was found to be independent of evoked response homeostasis suggesting that the two depend on different mechanisms.

Publication DOI: https://doi.org/10.1098/rstb.2016.0150
Divisions: College of Health & Life Sciences
Additional Information: © 2017 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Uncontrolled Keywords: synapse,LTP,experience-dependent,LTD,synaptic scaling,sensory cortex,Biochemistry, Genetics and Molecular Biology(all),Agricultural and Biological Sciences(all)
Publication ISSN: 1471-2970
Last Modified: 25 Mar 2024 08:20
Date Deposited: 23 Jan 2017 15:10
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2017-01-16
Accepted Date: 2016-10-03
Authors: Glazewski, Stanislaw
Greenhill, Stuart (ORCID Profile 0000-0002-5038-5258)
Fox, Kevin

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