Phase-amplitude coupled persistent theta and gamma oscillations in rat primary motor cortex in vitro


In vivo, theta (4-7 Hz) and gamma (30-80 Hz) neuronal network oscillations are known to coexist and display phase-amplitude coupling (PAC). However, in vitro, these oscillations have for many years been studied in isolation. Using an improved brain slice preparation technique we have, using co-application of carbachol (10 μM) and kainic acid (150 nM), elicited simultaneous theta (6.6 ± 0.1 Hz) and gamma (36.6 ± 0.4 Hz) oscillations in rodent primary motor cortex (M1). Each oscillation showed greatest power in layer V. Using a variety of time series analyses we detected significant cross-frequency coupling 74% of slice preparations. Differences were observed in the pharmacological profile of each oscillation. Thus, gamma oscillations were reduced by the GABAA receptor antagonists, gabazine (250 nM and 2 μM), and picrotoxin (50 μM) and augmented by AMPA receptor antagonism with SYM2206 (20 μM). In contrast, theta oscillatory power was increased by gabazine, picrotoxin and SYM2206. GABAB receptor blockade with CGP55845 (5 μM) increased both theta and gamma power, and similar effects were seen with diazepam, zolpidem, MK801 and a series of metabotropic glutamate receptor antagonists. Oscillatory activity at both frequencies was reduced by the gap junction blocker carbenoxolone (200 μM) and by atropine (5 μM). These data show theta and gamma oscillations in layer V of rat M1 in vitro are cross-frequency coupled, and are mechanistically distinct. The development of an in vitro model of phase-amplitude coupled oscillations will facilitate further mechanistic investigation of the generation and modulation of coupled activity in mammalian cortex.

Publication DOI:
Divisions: College of Health & Life Sciences > Aston Pharmacy School
College of Health & Life Sciences > School of Psychology
College of Health & Life Sciences > Clinical and Systems Neuroscience
College of Health & Life Sciences
College of Health & Life Sciences > Aston Institute of Health & Neurodevelopment (AIHN)
Additional Information: © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license ( Funding: BBSRC CASE-Studentship
Uncontrolled Keywords: gamma,M1,neuronal network oscillations,phase amplitude coupling,theta,Pharmacology,Cellular and Molecular Neuroscience
Publication ISSN: 1873-7064
Last Modified: 28 May 2024 07:11
Date Deposited: 24 Apr 2017 08:50
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2017-06
Published Online Date: 2017-04-08
Accepted Date: 2017-04-06
Submitted Date: 2016-09-15
Authors: Johnson, Nicholas W.
Özkan, Mazhar
Burgess, Adrian P. (ORCID Profile 0000-0002-0977-8105)
Prokic, Emma J.
Wafford, Keith A.
O'Neill, Michael J
Greenhill, Stuart D. (ORCID Profile 0000-0002-5038-5258)
Stanford, Ian M. (ORCID Profile 0000-0002-5677-8538)
Woodhall, Gavin L. (ORCID Profile 0000-0003-1281-9008)



Version: Published Version

License: Creative Commons Attribution

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