title: Finding synchrony in the desynchronized EEG: the history and interpretation of gamma rhythms.
abstract: Neocortical gamma (30-80 Hz) rhythms correlate with attention, movement and perception and are often disrupted in neurological and psychiatric disorders. Gamma primarily occurs during alert brain states characterized by the so-called "desynchronized" EEG. Is this because gamma rhythms are devoid of synchrony? In this review we take a historical approach to answering this question. Richard Caton and Adolf Beck were the first to report the rhythmic voltage fluctuations in the animal brain. They were limited by the poor amplification of their early galvanometers. Thus when they presented light or other stimuli, they observed a disappearance of the large resting oscillations. Several groups have since shown that visual stimuli lead to low amplitude gamma rhythms and that groups of neurons in the visual cortices fire together during individual gamma cycles. This synchronous firing can more strongly drive downstream neurons. We discuss how gamma-band synchrony can support ongoing communication between brain regions, and highlight an important fact: there is at least local neuronal synchrony during gamma rhythms. Thus, it is best to refer to the low amplitude, high frequency EEG as an "activated", not "desynchronized", EEG.
authors: Department of Neuroscience, Brown University Providence, RI, USA ; Department of Neurology, Massachusetts General Hospital, Harvard Medical School Boston, MA, USA.
authors: Omar J
authors: OJ
authors: Ahmed
authors: Sydney S
authors: SS
authors: Cash
keywords: desynchronized EEG; gamma oscillations; history of gamma rhythms; synchrony
references: Nature. 2010 Apr 22;464(7292):1155-60
references: 20414303
references: Electroencephalogr Clin Neurophysiol. 1969;:Suppl 28:1-36
references: 4188910
references: Ann N Y Acad Sci. 2008;1129:26-34
references: 18591466
references: Proc Natl Acad Sci U S A. 1992 Jun 15;89(12):5670-4
references: 1608977
references: J Neurosci. 1995 Jan;15(1 Pt 1):47-60
references: 7823151
references: Neuroinformatics. 2006 Winter;4(1):119-28
references: 16595862
references: Nature. 2006 Feb 9;439(7077):733-6
references: 16372022
references: Physiol Rev. 1985 Jan;65(1):37-100
references: 3880898
references: Neuron. 2013 May 8;78(3):523-36
references: 23664617
references: Neuron. 2001 Aug 16;31(3):477-85
references: 11516403
references: Proc Natl Acad Sci U S A. 2005 May 10;102(19):7002-7
references: 15870189
references: Behav Neurosci. 1985 Oct;99(5):964-78
references: 3843313
references: Nat Rev Neurosci. 2012 Jan 11;13(2):121-34
references: 22233726
references: Nature. 1995 Feb 16;373(6515):612-5
references: 7854418
references: Nat Neurosci. 2002 Aug;5(8):805-11
references: 12134152
references: J Neurosci. 1996 Oct 15;16(20):6402-13
references: 8815919
references: Electroencephalogr Clin Neurophysiol Suppl. 1978;(34):9-18
references: 285858
references: J Neurosci. 1993 Jan;13(1):334-50
references: 8423479
references: Nat Neurosci. 2000 Sep;3(9):904-10
references: 10966621
references: Nat Rev Neurosci. 2001 Oct;2(10):704-16
references: 11584308
references: Science. 1996 Apr 12;272(5259):225-6
references: 8602506
references: Trends Neurosci. 1996 Apr;19(4):130-7
references: 8658595
references: Nat Rev Neurosci. 2010 Feb;11(2):100-13
references: 20087360
references: Neuron. 2007 Sep 6;55(5):809-23
references: 17785187
references: EXS. 1989;57:159-71
references: 2533089
references: Isr J Med Sci. 1982 Jan;18(1):83-92
references: 6279540
references: Neuron. 2010 Sep 9;67(5):885-96
references: 20826318
references: Electroencephalogr Clin Neurophysiol. 1949 Nov;1(4):455-73
references: 18421835
references: Int J Neurosci. 1992 Sep;66(1-2):119-29
references: 1304564
references: Science. 1991 May 24;252(5009):1177-9
references: 2031188
references: Science. 1997 Dec 12;278(5345):1950-3
references: 9395398
references: Electroencephalogr Clin Neurophysiol. 1998 Feb;106(2):173-6
references: 9741779
references: J Neurosci. 2012 May 23;32(21):7373-83
references: 22623683
references: Proc Natl Acad Sci U S A. 1989 Mar;86(5):1698-702
references: 2922407
references: Neuron. 1999 Sep;24(1):67-77, 111-25
references: 10677027
references: J Comput Neurosci. 1998 Mar;5(1):5-16
references: 9580271
references: J Comput Neurosci. 1995 Dec;2(4):283-9
references: 8746402
references: Nature. 1999 Nov 4;402(6757):75-9
references: 10573419
references: J Neurosci. 2008 Jul 16;28(29):7334-43
references: 18632937
references: J Neurosci. 2011 Jun 29;31(26):9658-64
references: 21715631
references: J Physiol. 1996 Jun 1;493 ( Pt 2):471-84
references: 8782110
references: Nature. 1989 Mar 23;338(6213):334-7
references: 2922061
references: Neuron. 2009 May 28;62(4):566-77
references: 19477157
references: Science. 2007 Jun 15;316(5831):1609-12
references: 17569862
references: Neural Comput. 2003 Mar;15(3):509-38
references: 12620157
references: Science. 2001 Feb 23;291(5508):1560-3
references: 11222864
references: Annu Rev Neurosci. 2012;35:203-25
references: 22443509
references: Biophys J. 2009 Apr 8;96(7):2589-603
references: 19348744
references: Proc Natl Acad Sci U S A. 1996 Mar 19;93(6):2533-8
references: 8637909
references: Annu Rev Neurosci. 2009;32:209-24
references: 19400723
references: Nature. 2009 Jun 4;459(7247):663-7
references: 19396156
references: Science. 1936 Mar 13;83(2150):259-60
references: 17757098
references: Front Integr Neurosci. 2009 Jul 30;3:17
references: 19668703
references: Neuron. 2005 Aug 4;47(3):423-35
references: 16055065
references: Annu Rev Physiol. 1993;55:349-74
references: 8466179
references: Proc R Soc Med. 1936 Jan;29(3):197-200
references: 19990549
references: Electroencephalogr Clin Neurophysiol Suppl. 1991;42:47-57
references: 1915030
references: Neuron. 2009 Sep 24;63(6):727-32
references: 19778503
references: Proc Natl Acad Sci U S A. 1991 Jul 15;88(14):6048-52
references: 2068083