title: Sublinear integration underlies binocular processing in primary visual cortex.
abstract: Although we know much about the capacity of neurons to integrate synaptic inputs in vitro, less is known about synaptic integration in vivo. Here we address this issue by investigating the integration of inputs from the two eyes in mouse primary visual cortex. We find that binocular inputs to layer 2/3 pyramidal neurons are integrated sublinearly in an amplitude-dependent manner. Sublinear integration was greatest when binocular responses were largest, as occurs at the preferred orientation and binocular disparity, and highest contrast. Using voltage-clamp experiments and modeling, we show that sublinear integration occurs postsynaptically. The extent of sublinear integration cannot be accounted for solely by nonlinear integration of excitatory inputs, even when they are activated closely in space and time, but requires balanced recruitment of inhibition. Finally, we show that sublinear binocular integration acts as a divisive form of gain control, linearizing the output of binocular neurons and enhancing orientation selectivity.
authors: Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia. fabio.longordo@anu.edu.au
authors: Fabio
authors: F
authors: Longordo
authors: Minh-Son
authors: MS
authors: To
authors: Kaori
authors: K
authors: Ikeda
authors: Greg J
authors: GJ
authors: Stuart
mesh_terms: D000818:Animals; D004567:Electrodes, Implanted; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology; D009483:Neuropsychological Tests; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D015357:Vision Disparity / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology*; D015349:Vision, Monocular / Q000502:physiology; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*
references: J Neurosci. 2002 Jul 1;22(13):5259-64
references: 12097474
references: Nature. 2009 Feb 26;457(7233):1137-41
references: 19151696
references: Neuron. 2009 Dec 10;64(5):707-18
references: 20005826
references: J Neurosci. 2011 Nov 23;31(47):17134-48
references: 22114282
references: Nat Neurosci. 2004 Jun;7(6):621-7
references: 15156147
references: Nature. 1997 Jun 26;387(6636):869-75
references: 9202119
references: Neuroscience. 2002;113(4):1003-14
references: 12182904
references: Nature. 2000 Mar 16;404(6775):285-9
references: 10749211
references: Science. 1990 Aug 31;249(4972):1037-41
references: 2396096
references: Neuron. 2010 Jan 28;65(2):246-56
references: 20152130
references: J Physiol. 2007 Jan 15;578(Pt 2):507-25
references: 17095562
references: J Neurosci. 2008 Jul 23;28(30):7520-36
references: 18650330
references: Neuron. 2009 Apr 30;62(2):171-89
references: 19409263
references: Science. 2003 Dec 12;302(5652):1981-4
references: 14671309
references: Neuron. 1995 Nov;15(5):1065-76
references: 7576650
references: Vis Neurosci. 2005 Sep-Oct;22(5):661-76
references: 16332277
references: Nature. 2012 Oct 18;490(7420):397-401
references: 22940864
references: Proc Natl Acad Sci U S A. 1983 May;80(9):2799-802
references: 6573680
references: Neuron. 2011 Dec 22;72(6):1012-24
references: 22196336
references: Nature. 1999 Mar 25;398(6725):338-41
references: 10192334
references: J Neurosci. 2000 Jan 1;20(1):470-84
references: 10627623
references: Nat Neurosci. 1999 Jun;2(6):508-14
references: 10448214
references: Neuron. 2006 Apr 20;50(2):291-307
references: 16630839
references: Nat Neurosci. 2004 Oct;7(10):1113-22
references: 15338009
references: J Neurophysiol. 2006 Nov;96(5):2775-84
references: 16899631
references: J Neurosci. 2002 Jul 1;22(13):5639-51
references: 12097515
references: Science. 2012 Jan 20;335(6066):353-6
references: 22267814
references: J Physiol. 1997 Dec 15;505 ( Pt 3):617-32
references: 9457640
references: Nat Neurosci. 2007 Apr;10(4):462-8
references: 17334362
references: Science. 1995 Apr 14;268(5208):301-4
references: 7716525
references: Nature. 2012 Dec 13;492(7428):247-51
references: 23143335
references: J Neurophysiol. 1986 Jul;56(1):243-59
references: 3746399
references: Nature. 2010 Apr 29;464(7293):1307-12
references: 20428163
references: Nat Neurosci. 2008 Jul;11(7):790-8
references: 18552844
references: Neuron. 2011 Aug 11;71(3):512-28
references: 21835347
references: Science. 2012 Feb 24;335(6071):989-93
references: 22363012
references: Proc Natl Acad Sci U S A. 2011 Sep 13;108(37):15420-5
references: 21876170
references: J Neurosci. 2011 Aug 24;31(34):12339-50
references: 21865476
references: Nature. 2011 Jun 26;475(7357):501-5
references: 21706031
references: Vision Res. 1991;31(7-8):1079-86
references: 1909826
references: J Neurophysiol. 1999 Aug;82(2):874-90
references: 10444684
references: J Neurophysiol. 1997 Nov;78(5):2772-89
references: 9356425
references: Neuron. 2011 Mar 10;69(5):885-92
references: 21382549
references: Nature. 1991 Jul 11;352(6331):156-9
references: 2067576
references: Neuron. 1999 Feb;22(2):383-94
references: 10069343
references: J Neurosci. 1998 Jan 1;18(1):10-5
references: 9412481
references: J Physiol. 1997 Dec 15;505 ( Pt 3):605-16
references: 9457639
references: Nature. 1998 May 28;393(6683):369-73
references: 9620800
references: Nature. 2012 Aug 16;488(7411):379-83
references: 22878719
references: Neuron. 2012 Jan 12;73(1):159-70
references: 22243754
references: Nature. 2011 Jul 27;477(7363):171-8
references: 21796121
references: Nature. 2012 Aug 16;488(7411):343-8
references: 22878717
references: Pflugers Arch. 2002 Jul;444(4):491-8
references: 12136268
references: J Neurophysiol. 1986 Jul;56(1):221-42
references: 3746398
references: Science. 2002 Mar 8;295(5561):1907-10
references: 11884759