title: Motor cortex broadly engages excitatory and inhibitory neurons in somatosensory barrel cortex.
abstract: Anatomical studies have shown that primary somatosensory (S1) and primary motor (M1) cortices are reciprocally connected. The M1 to S1 projection is thought to represent a modulatory signal that conveys motor-related information to S1. Here, we investigated M1 synaptic inputs to S1 by injecting an AAV virus containing channelrhodopsin-2 and a fluorescent tag into M1. Consistent with previous results, we found labeling of M1 axons within S1 that was most robust in the deep layers and in L1. Labeling was sparse in L4 and was concentrated in the interbarrel septa, largely avoiding barrel centers. In S1, we recorded in vitro from regular-spiking excitatory neurons and fast-spiking and somatostatin-expressing inhibitory interneurons. All 3 cell types had a high probability of receiving direct excitatory M1 input. Both excitatory and inhibitory cells within L4 were the least likely to receive such input from M1. Disynaptic inhibition was observed frequently, indicating that M1 recruits substantial inhibition within S1. Additionally, a subpopulation of L6 regular-spiking excitatory neurons received exceptionally strong M1 input. Overall, our results suggest that activation of M1 evokes within S1 a bombardment of excitatory and inhibitory synaptic activity that could contribute in a layer-specific manner to state-dependent changes in S1.
authors.affiliation: Center for Neuroscience, University of Pittsburgh, Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA akk31@pitt.edu.
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Kinnischtzke
authors.affiliation: Center for Neuroscience, University of Pittsburgh, Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Simons
authors.affiliation: Center for Neuroscience, University of Pittsburgh, Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: Erika E
authors.initials: EE
authors.lastname: Fanselow
mesh_terms: D000200:Action Potentials; D000818:Animals; D019706:Excitatory Postsynaptic Potentials; D049452:Green Fluorescent Proteins / Q000235:genetics; D053444:Inhibitory Postsynaptic Potentials; D008822:Mice, Transgenic; D009044:Motor Cortex / Q000166:cytology / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D056347:Neuroanatomical Tract-Tracing Techniques; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D061848:Optical Imaging; D062308:Optogenetics; D018408:Patch-Clamp Techniques; D013003:Somatosensory Cortex / Q000166:cytology / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D046509:Tissue Culture Techniques
chemical_list: D049452:Green Fluorescent Proteins
keywords: active touch; cortical circuits; interneurons; optogenetics; sensorimotor integration
references.citation: Cereb Cortex. 1991 Jan-Feb;1(1):1-47
references.pmid: 1822724
references.citation: Neuron. 2011 Oct 20;72(2):344-56
references.pmid: 22017992
references.citation: Nature. 2007 Aug 16;448(7155):802-6
references.pmid: 17700699
references.citation: Neuron. 2002 Apr 25;34(3):437-46
references.pmid: 11988174
references.citation: Science. 2010 Jan 29;327(5965):587-90
references.pmid: 20110507
references.citation: Nature. 2009 Feb 26;457(7233):1142-5
references.pmid: 19151697
references.citation: J Neurophysiol. 2002 Oct;88(4):1924-32
references.pmid: 12364518
references.citation: J Neurophysiol. 2003 Nov;90(5):2987-3000
references.pmid: 12815025
references.citation: PLoS Biol. 2011 Jan 04;9(1):e1000572
references.pmid: 21245906
references.citation: Neuron. 2010 Feb 11;65(3):422-35
references.pmid: 20159454
references.citation: J Comp Neurol. 2003 Sep 8;464(1):98-103
references.pmid: 12866130
references.citation: J Neurosci. 1992 Jan;12(1):319-29
references.pmid: 1729440
references.citation: J Neurosci. 2000 May 1;20(9):3354-68
references.pmid: 10777798
references.citation: Nat Neurosci. 2012 Feb 26;15(4):607-12
references.pmid: 22366760
references.citation: Proc Natl Acad Sci U S A. 2003 Nov 25;100(24):13940-5
references.pmid: 14615590
references.citation: J Neurophysiol. 2008 Jun;99(6):2998-3008
references.pmid: 18417631
references.citation: Nat Neurosci. 2007 Jun;10(6):743-53
references.pmid: 17515899
references.citation: Neuron. 2010 Jan 28;65(2):230-45
references.pmid: 20152129
references.citation: J Neurophysiol. 2002 Aug;88(2):740-50
references.pmid: 12163526
references.citation: J Comp Neurol. 1990 Jan 1;291(1):43-54
references.pmid: 2298929
references.citation: Nat Neurosci. 2007 Apr;10(4):462-8
references.pmid: 17334362
references.citation: J Neurosci. 1997 Aug 15;17(16):6365-79
references.pmid: 9236245
references.citation: J Comp Neurol. 1998 Jan 12;390(2):297-310
references.pmid: 9453672
references.citation: Cereb Cortex. 2008 May;18(5):979-89
references.pmid: 17702950
references.citation: J Neurophysiol. 1989 Feb;61(2):311-30
references.pmid: 2918357
references.citation: Proc Natl Acad Sci U S A. 2004 Dec 28;101(52):18206-11
references.pmid: 15608064
references.citation: Nat Neurosci. 2005 Sep;8(9):1263-8
references.pmid: 16116447
references.citation: Pflugers Arch. 2006 Dec;453(3):269-81
references.pmid: 16736208
references.citation: Cereb Cortex. 2010 Oct;20(10):2265-76
references.pmid: 20453248
references.citation: Brain Res. 1973 Mar 15;51:326-31
references.pmid: 4706020
references.citation: J Neurophysiol. 1989 Jul;62(1):288-308
references.pmid: 2754479
references.citation: Nat Rev Neurosci. 2004 Oct;5(10):793-807
references.pmid: 15378039
references.citation: Nature. 2004 Jun 17;429(6993):717-23
references.pmid: 15170216
references.citation: J Comp Neurol. 1983 Mar 1;214(3):279-89
references.pmid: 6853758
references.citation: J Comp Neurol. 2004 Dec 13;480(3):299-309
references.pmid: 15515173
references.citation: Nat Neurosci. 2008 Dec;11(12):1430-8
references.pmid: 19011625
references.citation: J Neurosci. 2005 May 18;25(20):4985-95
references.pmid: 15901779
references.citation: J Neurosci. 2011 Sep 14;31(37):13260-71
references.pmid: 21917809
references.citation: J Neurosci. 1999 Sep 1;19(17):7603-16
references.pmid: 10460266
references.citation: J Neurophysiol. 2012 Jan;107(2):551-63
references.pmid: 21994257
references.citation: J Neurophysiol. 2006 Feb;95(2):1274-7
references.pmid: 16251259
references.citation: Cereb Cortex. 2009 Apr;19(4):951-62
references.pmid: 18802122
references.citation: Cereb Cortex. 2011 Jun;21(6):1351-61
references.pmid: 21068186
references.citation: Neuron. 2007 Dec 6;56(5):907-23
references.pmid: 18054865
references.citation: J Neurophysiol. 2008 Nov;100(5):2640-52
references.pmid: 18799598
references.citation: J Neurosci. 2008 Feb 20;28(8):1789-97
references.pmid: 18287495
references.citation: J Neurophysiol. 2007 Dec;98(6):3330-40
references.pmid: 17898147
references.citation: Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):2076-81
references.pmid: 12569169
references.citation: J Neurosci. 2001 Apr 15;21(8):2699-710
references.pmid: 11306623
references.citation: Cereb Cortex. 2003 Jan;13(1):25-32
references.pmid: 12466212
references.citation: Cereb Cortex. 2006 Aug;16(8):1142-56
references.pmid: 16221924
references.citation: Science. 2004 Jun 25;304(5679):1989-92
references.pmid: 15218154
references.citation: J Comp Neurol. 1989 Jul 15;285(3):325-38
references.pmid: 2547850
references.citation: Neuron. 2011 Oct 6;72(1):111-23
references.pmid: 21982373
references.citation: J Neurosci. 2006 May 10;26(19):5069-82
references.pmid: 16687498
references.citation: Neuroscience. 2009 Jun 30;161(2):441-50
references.pmid: 19318117
references.citation: Proc Natl Acad Sci U S A. 1998 Apr 28;95(9):5323-8
references.pmid: 9560274
references.citation: J Neurosci. 2010 Dec 15;30(50):16796-808
references.pmid: 21159951
references.citation: Neuron. 2007 Mar 1;53(5):735-46
references.pmid: 17329212
references.citation: Science. 2001 Aug 10;293(5532):1159-63
references.pmid: 11498596
references.citation: Somatosens Mot Res. 2011;28(3-4):63-72
references.pmid: 21879990
references.citation: Front Neurosci. 2007 Oct 15;1(1):19-42
references.pmid: 18982117
references.citation: Somatosens Mot Res. 1996;13(2):115-27
references.pmid: 8844960
references.citation: Neuron. 2002 Aug 15;35(4):773-82
references.pmid: 12194875
references.citation: Neuron. 2005 Oct 20;48(2):315-27
references.pmid: 16242411
references.citation: Nat Neurosci. 1998 Aug;1(4):279-85
references.pmid: 10195160
references.citation: Nature. 2012 Aug 16;488(7411):379-83
references.pmid: 22878719
references.citation: Front Neural Circuits. 2012 May 31;6:33
references.pmid: 22666189
references.citation: Nature. 2008 Aug 14;454(7206):881-5
references.pmid: 18633351
references.citation: J Comp Neurol. 1977 Oct 15;175(4):455-82
references.pmid: 915034
references.citation: J Neurosci. 2011 Mar 9;31(10):3862-70
references.pmid: 21389241
references.citation: Nature. 2012 Aug 16;488(7411):343-8
references.pmid: 22878717
references.citation: Curr Opin Neurobiol. 2006 Aug;16(4):435-44
references.pmid: 16837190
references.citation: J Neurophysiol. 1997 Aug;78(2):1144-9
references.pmid: 9307141
references.citation: Exp Neurol. 1982 Dec;78(3):654-69
references.pmid: 6293865
references.citation: Nat Rev Neurosci. 2008 Jul;9(7):557-68
references.pmid: 18568015
references.citation: Neuron. 1997 Sep;19(3):679-86
references.pmid: 9331357
references.citation: Nat Neurosci. 2010 Mar;13(3):387-92
references.pmid: 20081849
references.citation: Cereb Cortex. 2004 Oct;14(10):1059-70
references.pmid: 15115747
references.citation: J Neurosci. 2009 Aug 19;29(33):10321-34
references.pmid: 19692606