title: Statistical traces of long-term memories stored in strengths and patterns of synaptic connections.
abstract: Learning and long-term memory rely on plasticity of neural circuits. In adult cerebral cortex, plasticity can result from potentiation and depression of synaptic strengths and structural reorganization of circuits through growth and retraction of dendritic spines. By analyzing 166 distributions of spine head volumes and spine lengths from mouse, rat, monkey, and human brains, we determine the "generalized cost" of dendritic spines. This cost universally depends on spine shape, i.e., the dependence is the same in all the analyzed systems. We show that, in adult, synaptic strength and structural synaptic plasticity mechanisms are in statistical equilibrium, the numbers of dendritic spines in different cortical areas are nearly optimally chosen for memory storage, and the distributions of spine lengths and head volumes are governed by a single parameter--the effective temperature. We suggest that the effective temperature may be viewed as a measure of circuit stability or longevity of stored memories.
authors: Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, USA. a.stepanyants@neu.edu
authors: Armen
authors: A
authors: Stepanyants
authors: Gina
authors: G
authors: Escobar
references: J Neurosci. 2004 Aug 4;24(31):6928-38
references: 15295028
references: Nat Rev Neurosci. 2009 Sep;10(9):647-58
references: 19693029
references: J Anat. 1967 Sep;101(Pt 4):639-54
references: 4964696
references: Trends Neurosci. 2003 Jul;26(7):360-8
references: 12850432
references: Nature. 2009 Dec 17;462(7275):920-4
references: 19946265
references: Stroke. 2008 Apr;39(4):1286-91
references: 18323506
references: J Neurosci. 1988 Dec;8(12):4455-69
references: 3199186
references: J Neurosci. 2003 Jan 15;23(2):659-65
references: 12533625
references: Proc R Soc Lond B Biol Sci. 1970 Nov 3;176(1043):161-234
references: 4394740
references: Nat Neurosci. 2004 Dec;7(12):1345-52
references: 15558066
references: Neuron. 2005 Apr 21;46(2):181-9
references: 15848798
references: Brain Res. 2004 Jan 16;996(1):89-96
references: 14670635
references: Neuron. 1998 Sep;21(3):545-59
references: 9768841
references: Neuroscience. 2006;138(2):403-9
references: 16457955
references: J Cereb Blood Flow Metab. 2001 Oct;21(10):1133-45
references: 11598490
references: J Neurosci. 2008 Sep 10;28(37):9249-60
references: 18784305
references: Nat Neurosci. 2006 Sep;9(9):1117-24
references: 16892056
references: J Neurosci. 2008 May 28;28(22):5740-51
references: 18509035
references: Cell. 2008 Jul 11;134(1):175-87
references: 18614020
references: Nature. 2002 Dec 19-26;420(6917):812-6
references: 12490949
references: J Neurosci. 1989 Aug;9(8):2982-97
references: 2769375
references: J Neurosci. 2008 Feb 13;28(7):1697-708
references: 18272690
references: Curr Opin Neurobiol. 2007 Jun;17(3):381-6
references: 17498943
references: Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):4107-12
references: 10097171
references: J Neurocytol. 2002 Mar-Jun;31(3-5):337-46
references: 12815251
references: Neuron. 2009 Jan 29;61(2):247-58
references: 19186167
references: J Neurosci. 2008 Dec 10;28(50):13592-608
references: 19074033
references: Neuron. 2010 Sep 23;67(6):1009-20
references: 20869597
references: Annu Rev Neurosci. 2001;24:1071-89
references: 11520928
references: Nature. 2004 Jun 17;429(6993):761-6
references: 15190253
references: Nat Neurosci. 1999 Jul;2(7):618-24
references: 10409387
references: Front Neurosci. 2007 Oct 15;1(1):131-43
references: 18982124
references: J Neurosci. 1993 Jul;13(7):2801-20
references: 8331373
references: Mol Cell Biol. 2008 May;28(9):2896-907
references: 18316402
references: Nature. 1998 Feb 26;391(6670):892-6
references: 9495341
references: Neurosci Res. 2007 Jan;57(1):1-9
references: 17070951
references: Nature. 2009 Dec 17;462(7275):915-9
references: 19946267
references: J Neurosci. 2003 Aug 6;23(18):7129-42
references: 12904473
references: Neuron. 2002 Apr 11;34(2):275-88
references: 11970869
references: PLoS Biol. 2006 Oct;4(11):e343
references: 17048987
references: Proc Natl Acad Sci U S A. 2009 Mar 3;106(9):3555-60
references: 19221032
references: Proc Natl Acad Sci U S A. 2007 Dec 4;104(49):19553-8
references: 18048342
references: Nature. 2004 Oct 14;431(7010):782-8
references: 15483599
references: J Neurosci. 2008 Aug 20;28(34):8477-88
references: 18716206
references: J Neurosci. 1997 Aug 1;17(15):5858-67
references: 9221783
references: Cereb Cortex. 2009 Mar;19(3):586-92
references: 18632740
references: Proc Natl Acad Sci U S A. 2009 Sep 22;106(38):16463-8
references: 19805321
references: Neuron. 2004 Dec 2;44(5):749-57
references: 15572107
references: Neural Comput. 2001 Apr;13(4):799-815
references: 11255570
references: Proc Natl Acad Sci U S A. 2003 Sep 2;100(18):10494-9
references: 12928494
references: Science. 1997 Jan 10;275(5297):213-5
references: 8985014
references: J Cogn Neurosci. 2009 Nov;21(11):2047-72
references: 19485699
references: Neuron. 2006 Nov 9;52(3):409-23
references: 17088208
references: J Physiol. 1973 Jul;232(2):331-56
references: 4727084
references: Proc Natl Acad Sci U S A. 2002 Feb 5;99(3):1639-44
references: 11818568
references: J Neurosci. 2006 Feb 15;26(7):2000-9
references: 16481433
references: Neuron. 2004 Sep 2;43(5):609-17
references: 15339643
references: Nature. 2002 Dec 19-26;420(6917):788-94
references: 12490942
references: Exp Neurol. 2006 Apr;198(2):401-15
references: 16443221
references: J Neurosci. 1992 Jul;12(7):2685-705
references: 1613552
references: J Comp Neurol. 1999 Sep 20;412(2):292-302
references: 10441757
references: Nat Rev Neurosci. 2005 Feb;6(2):119-30
references: 15685217
references: Proc Natl Acad Sci U S A. 2009 Jul 28;106(30):12524-9
references: 19592509
references: Nat Neurosci. 2004 Apr;7(4):364-72
references: 15034583
references: Trends Neurosci. 2005 Jul;28(7):387-94
references: 15935485
references: Cereb Cortex. 2001 Feb;11(2):93-103
references: 11208664
references: Cereb Cortex. 1997 Oct-Nov;7(7):619-34
references: 9373018
references: J Neurosci. 2001 Jul 15;21(14):5139-46
references: 11438589
references: Cereb Cortex. 1998 Dec;8(8):671-84
references: 9863695
references: Neuron. 2005 Jan 20;45(2):279-91
references: 15664179
references: J Neurobiol. 2003 Aug;56(2):95-112
references: 12838576
references: J Comp Neurol. 1999 Nov 8;414(1):57-66
references: 10494078
references: Nature. 2007 Dec 20;450(7173):1195-200
references: 18097401