title: Dendritic atrophy constricts functional maps in resonance and impedance properties of hippocampal model neurons.
abstract: A gradient in the density of hyperpolarization-activated cyclic-nucleotide gated (HCN) channels is necessary for the emergence of several functional maps within hippocampal pyramidal neurons. Here, we systematically analyzed the impact of dendritic atrophy on nine such functional maps, related to input resistance and local/transfer impedance properties, using conductance-based models of hippocampal pyramidal neurons. We introduced progressive dendritic atrophy in a CA1 pyramidal neuron reconstruction through a pruning algorithm, measured all functional maps in each pruned reconstruction, and arrived at functional forms for the dependence of underlying measurements on dendritic length. We found that, across frequencies, atrophied neurons responded with higher efficiency to incoming inputs, and the transfer of signals across the dendritic tree was more effective in an atrophied reconstruction. Importantly, despite the presence of identical HCN-channel density gradients, spatial gradients in input resistance, local/transfer resonance frequencies and impedance profiles were significantly constricted in reconstructions with dendritic atrophy, where these physiological measurements across dendritic locations converged to similar values. These results revealed that, in atrophied dendritic structures, the presence of an ion channel density gradient alone was insufficient to sustain homologous functional maps along the same neuronal topograph. We assessed the biophysical basis for these conclusions and found that this atrophy-induced constriction of functional maps was mediated by an enhanced spatial spread of the influence of an HCN-channel cluster in atrophied trees. These results demonstrated that the influence fields of ion channel conductances need to be localized for channel gradients to express themselves as homologous functional maps, suggesting that ion channel gradients are necessary but not sufficient for the emergence of functional maps within single neurons.
authors: Cellular Neurophysiology Laboratory, Indian Institute of Science Bangalore, India ; Centre for Converging Technologies, University of Rajasthan Jaipur, India.
authors: Neha
authors: N
authors: Dhupia
authors: Cellular Neurophysiology Laboratory, Indian Institute of Science Bangalore, India.
authors: Rahul K
authors: RK
authors: Rathour
authors: Cellular Neurophysiology Laboratory, Indian Institute of Science Bangalore, India.
authors: Rishikesh
authors: R
authors: Narayanan
keywords: HCN channel; dendritic morphology; functional maps; impedance; resonance
references: J Neurosci. 2014 Jan 22;34(4):1195-211
references: 24453312
references: Hippocampus. 2004;14(5):636-48
references: 15301440
references: PLoS Comput Biol. 2014 Aug 21;10(8):e1003775
references: 25144440
references: Nat Rev Neurosci. 2012 Feb 08;13(3):157-68
references: 22314443
references: Science. 2000 Oct 27;290(5492):739-44
references: 11052929
references: J Physiol. 2012 Nov 15;590(22):5707-22
references: 22988138
references: J Gen Physiol. 1941 Jul 20;24(6):771-88
references: 19873252
references: J Neurophysiol. 2012 May;107(9):2313-34
references: 22262825
references: Trends Neurosci. 2000 May;23(5):216-22
references: 10782127
references: J Gen Physiol. 1932 Jul 20;15(6):641-9
references: 19872673
references: J Neurophysiol. 2003 Jun;89(6):3143-54
references: 12612010
references: J Neurophysiol. 2002 Jun;87(6):2753-9
references: 12037177
references: J Biol Chem. 2012 May 18;287(21):17656-61
references: 22511771
references: Annu Rev Neurosci. 1999;22:105-22
references: 10202533
references: Physiol Rev. 2008 Oct;88(4):1407-47
references: 18923186
references: J Neurophysiol. 1996 Aug;76(2):698-714
references: 8871192
references: Proc Natl Acad Sci U S A. 1996 Apr 30;93(9):3908-13
references: 8632988
references: PLoS One. 2013 Nov 05;8(11):e78908
references: 24223864
references: J Comp Neurol. 1995 Sep 11;360(1):150-60
references: 7499560
references: Physiol Rev. 2008 Apr;88(2):769-840
references: 18391179
references: Brain Res Dev Brain Res. 2003 Mar 14;141(1-2):55-61
references: 12644248
references: Nat Rev Neurosci. 2006 Jul;7(7):548-62
references: 16791144
references: J Neurosci. 2005 Oct 12;25(41):9328-38
references: 16221841
references: Nature. 1996 Jul 25;382(6589):363-6
references: 8684467
references: Philos Trans R Soc Lond B Biol Sci. 2003 Apr 29;358(1432):667-74
references: 12740112
references: Behav Brain Res. 2005 Aug 30;163(1):78-90
references: 15913801
references: Hippocampus. 2005;15(1):97-103
references: 15390161
references: Neuron. 2007 Dec 20;56(6):1061-75
references: 18093527
references: Nat Neurosci. 2004 Sep;7(9):961-7
references: 15322550
references: J Neurophysiol. 2001 Feb;85(2):926-37
references: 11160523
references: J Neurosci. 2013 Jan 30;33(5):2156-65
references: 23365251
references: Brain Res. 1971 Nov;34(1):171-5
references: 5124915
references: Nat Rev Neurosci. 2008 Mar;9(3):206-21
references: 18270515
references: Nat Rev Neurosci. 2004 Feb;5(2):97-107
references: 14735113
references: J Neural Transm Suppl. 1994;44:133-43
references: 7897386
references: Hippocampus. 1993 Jul;3(3):317-30
references: 8353611
references: Neuron. 2002 Jan 31;33(3):439-52
references: 11832230
references: J Neurophysiol. 2012 Nov;108(9):2343-51
references: 22933729
references: J Physiol. 2007 Jan 15;578(Pt 2):507-25
references: 17095562
references: Neuron. 2002 Jan 31;33(3):325-40
references: 11832222
references: Nat Neurosci. 2013 Dec;16(12):1812-20
references: 24185428
references: J Neurosci. 2007 Feb 21;27(8):1853-67
references: 17314282
references: Neurobiol Learn Mem. 2013 Oct;105:186-99
references: 23871744
references: J Neurosci. 1998 Oct 1;18(19):7613-24
references: 9742133
references: J Physiol. 2002 Dec 15;545(Pt 3):783-805
references: 12482886
references: Neuroscience. 2003;116(3):715-32
references: 12573714
references: Neurobiol Aging. 1997 Jan-Feb;18(1):1-11
references: 8983027
references: Nat Rev Neurosci. 2013 Sep;14 (9):638-48
references: 23900412
references: Neuron. 2013 Mar 20;77(6):1002-16
references: 23522038
references: Annu Rev Neurosci. 2011;34:89-103
references: 21438687
references: Annu Rev Neurosci. 2005;28:503-32
references: 16033324
references: J Comp Neurol. 1998 Feb 16;391(3):335-52
references: 9492204
references: Nat Rev Neurosci. 2000 Dec;1(3):181-90
references: 11257906
references: Annu Rev Psychol. 2010;61:111-40, C1-3
references: 19575621
references: J Comp Neurol. 1995 Nov 6;362(1):17-45
references: 8576427
references: J Neurosci. 2003 Apr 15;23(8):3243-50
references: 12716931
references: J Neurosci. 2009 Nov 18;29(46):14472-83
references: 19923281
references: Neuron. 2014 May 21;82(4):809-21
references: 24853940
references: Neuroimage. 2012 Oct 15;63(1):194-202
references: 22766164
references: J Physiol. 2012 Nov 15;590(22):5629-52
references: 22930270
references: J Neurosci. 2007 Aug 29;27(35):9247-51
references: 17728438
references: J Neurophysiol. 2010 Aug;104(2):1020-33
references: 20554832
references: Brain Res Bull. 1981 Aug;7(2):113-20
references: 7272792
references: J Neurophysiol. 2013 Apr;109(7):1940-53
references: 23324324
references: Physiol Rev. 2010 Jul;90(3):1195-268
references: 20664082
references: Curr Opin Neurobiol. 2012 Jun;22(3):366-71
references: 22033281
references: J Physiol. 2013 Apr 1;591(7):1645-69
references: 23283761
references: Brain Res. 2002 Jun 21;941(1-2):11-28
references: 12031543
references: Brain Struct Funct. 2015 Mar;220(2):1205-12
references: 24500370
references: J Neurobiol. 2006 Jan;66(1):71-81
references: 16216005
references: J Biol Chem. 2009 Feb 27;284(9):5445-9
references: 18940805
references: Proc Natl Acad Sci U S A. 2014 Apr 29;111(17):E1787-96
references: 24711394
references: Brain Res. 1991 Feb 1;540(1-2):63-82
references: 2054634
references: Network. 2002 Aug;13(3):311-25
references: 12222816
references: Front Comput Neurosci. 2010 Sep 23;4:128
references: 21258425
references: Physiol Behav. 1998 Aug;65(1):43-9
references: 9811363
references: Nat Rev Neurosci. 2008 Jan;9(1):65-75
references: 18094707
references: J Neurophysiol. 2010 Jun;103(6):3070-83
references: 20457854
references: Biol Psychiatry. 2006 Jan 15;59(2):155-61
references: 16125145
references: J Physiol. 2000 Nov 15;529 Pt 1:205-13
references: 11080262
references: J Neurosci. 2008 May 28;28(22):5846-60
references: 18509046
references: J Neurosci. 2012 Mar 14;32(11):3736-47
references: 22423094
references: Nat Neurosci. 2002 Aug;5(8):767-74
references: 12118259
references: J Psychiatry Neurosci. 2004 Nov;29(6):417-26
references: 15644983
references: Nat Neurosci. 2002 Nov;5(11):1185-93
references: 12389030
references: Neural Comput. 2005 Jan;17(1):75-96
references: 15563748
references: PLoS One. 2013;8(2):e55590
references: 23390543
references: Acta Morphol Hung. 1989;37(1-2):3-10
references: 2518346
references: Nat Neurosci. 1999 Jun;2(6):508-14
references: 10448214
references: Can J Physiol Pharmacol. 1984 Apr;62(4):460-2
references: 6733594
references: PLoS Comput Biol. 2010 May 13;6(5):e1000781
references: 20485556
references: Trends Neurosci. 2008 Jun;31(6):309-16
references: 18471907
references: Nat Rev Neurosci. 2010 Apr;11(4):239-51
references: 20300102
references: Hippocampus. 2004;14(6):742-51
references: 15318332
references: Brain Res Rev. 2007 Aug;55(1):78-88
references: 17561265