title: Cell death triggers olfactory circuit plasticity via glial signaling in Drosophila.
abstract: The Drosophila antennal lobe is organized into glomerular compartments, where olfactory receptor neurons synapse onto projection neurons. Projection neuron dendrites also receive input from local neurons, which interconnect glomeruli. In this study, we investigated how activity in this circuit changes over time when sensory afferents are chronically removed in vivo. In the normal circuit, excitatory connections between glomeruli are weak. However, after we chronically severed receptor neuron axons projecting to a subset of glomeruli, we found that odor-evoked lateral excitatory input to deafferented projection neurons was potentiated severalfold. This was caused, at least in part, by strengthened electrical coupling from excitatory local neurons onto projection neurons, as well as increased activity in excitatory local neurons. Merely silencing receptor neurons was not sufficient to elicit these changes, implying that severing receptor neuron axons is the relevant signal. When we expressed the neuroprotective gene Wallerian degeneration slow (Wld(S)) in receptor neurons before severing their axons, this blocked the induction of plasticity. Because expressing Wld(S) prevents severed axons from recruiting glia, this result suggests a role for glia. Consistent with this, we found that blocking endocytosis in ensheathing glia blocked the induction of plasticity. In sum, these results reveal a novel injury response whereby severed sensory axons recruit glia, which in turn signal to central neurons to upregulate their activity. By strengthening excitatory interactions between neurons in a deafferented brain region, this mechanism might help boost activity to compensate for lost sensory input.
authors: Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Hokto
authors: H
authors: Kazama
authors: Emre
authors: E
authors: Yaksi
authors: Rachel I
authors: RI
authors: Wilson
references: Curr Biol. 2003 Feb 18;13(4):286-96
references: 12593794
references: Cell. 2009 Jan 9;136(1):149-62
references: 19135896
references: Nat Neurosci. 2010 Apr;13(4):439-49
references: 20139975
references: Neuron. 2004 Sep 2;43(5):703-14
references: 15339651
references: Philos Trans R Soc Lond B Biol Sci. 2009 Feb 12;364(1515):341-55
references: 18977729
references: Neuron. 2010 Apr 29;66(2):287-99
references: 20435004
references: Neuron Glia Biol. 2007 Feb;3(1):63-74
references: 18172512
references: J Neurobiol. 2001 May;47(2):81-92
references: 11291099
references: Neuron. 1999 Mar;22(3):451-61
references: 10197526
references: Neuron. 2003 Mar 6;37(5):827-41
references: 12628173
references: J Neurosci. 2009 Apr 15;29(15):4768-81
references: 19369546
references: J Neurosci. 2007 Aug 29;27(35):9427-38
references: 17728456
references: Nature. 2006 Apr 20;440(7087):1054-9
references: 16547515
references: Neuron. 2004 May 13;42(3):437-49
references: 15134640
references: Nature. 1990 Dec 6;348(6301):542-5
references: 2174130
references: Nat Rev Neurosci. 2009 Jul;10(7):495-506
references: 19491906
references: J Neurosci. 2005 Sep 14;25(37):8359-67
references: 16162917
references: J Neurosci. 2003 Oct 29;23(30):9906-12
references: 14586020
references: Neuron. 2006 Jun 15;50(6):883-95
references: 16772170
references: Neuron. 2008 Nov 6;60(3):430-40
references: 18995817
references: Neuroscience. 2005;130(4):853-65
references: 15652984
references: J Neurosci. 2008 Oct 22;28(43):10990-1002
references: 18945907
references: Glia. 1990;3(1):17-25
references: 2138132
references: Curr Biol. 2005 Sep 6;15(17):1535-47
references: 16139208
references: Science. 2005 Nov 4;310(5749):810-5
references: 16272113
references: J Neurosci. 1995 Aug;15(8):5574-81
references: 7643202
references: Curr Biol. 2004 Mar 23;14(6):449-57
references: 15043809
references: Nat Neurosci. 2009 Sep;12(9):1136-44
references: 19684589
references: Brain Res. 1994 Nov 14;663(2):206-14
references: 7874503
references: Cell. 2006 Apr 7;125(1):143-60
references: 16615896
references: Neuron. 1998 Sep;21(3):505-20
references: 9768838
references: Science. 2000 Dec 15;290(5499):2155-9
references: 11118151
references: Neuron. 2010 Sep 23;67(6):1034-47
references: 20869599
references: J Neurosci. 2006 Mar 29;26(13):3367-76
references: 16571743
references: Neuron. 2007 Dec 6;56(5):838-50
references: 18054860
references: J Comp Neurol. 1992 Apr 22;318(4):415-25
references: 1374444
references: Cell. 2000 Jul 21;102(2):147-59
references: 10943836
references: Nature. 1982 Oct 14;299(5884):583-91
references: 6811951
references: Rouxs Arch Dev Biol. 1995 May;204(5):284-307
references: 28306125
references: Proc Natl Acad Sci U S A. 1992 Dec 15;89(24):12088-92
references: 1334556
references: Annu Rev Neurosci. 2009;32:33-55
references: 19400721
references: Cell. 2007 Feb 9;128(3):601-12
references: 17289577
references: J Cell Sci. 1972 May;10(3):585-619
references: 5038407
references: J Neurosci. 2005 Oct 5;25(40):9069-79
references: 16207866
references: Science. 2005 Dec 16;310(5755):1809-13
references: 16357260
references: Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):13272-7
references: 9789078
references: Curr Biol. 2005 Dec 6;15(23):2086-96
references: 16332533
references: Philos Trans R Soc Lond B Biol Sci. 2009 Feb 12;364(1515):357-67
references: 18977732
references: Neuron. 2008 Jun 12;58(5):673-80
references: 18549780
references: Neuron. 2007 Apr 5;54(1):89-103
references: 17408580
references: J Neurobiol. 1997 May;32(5):443-56
references: 9110257
references: Neurosignals. 2008;16(4):278-88
references: 18635944
references: Ann N Y Acad Sci. 1998 Nov 16;860:155-67
references: 9928309
references: Annu Rev Physiol. 2010;72:335-55
references: 20148679
references: Neuron. 2010 Sep 23;67(6):1021-33
references: 20869598
references: Cell Tissue Res. 1990 Oct;262(1):9-34
references: 2124174
references: J Neurosci. 1990 Oct;10(10):3402-12
references: 1976769
references: Neuron. 2006 Jun 15;50(6):869-81
references: 16772169
references: Prog Neurobiol. 2010 Apr;90(4):471-97
references: 20109517
references: Neuron. 2008 May 8;58(3):401-13
references: 18466750