Dendritic atrophy constricts functional maps in resonance and impedance properties of hippocampal model neurons

Neha Dhupia, Rahul K. Rathour, Rishikesh Narayanan

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Article number456
Pages (from-to)1-17
Number of pages17
JournalFrontiers in Cellular Neuroscience
Issue numberJAN
StatePublished - 12 Jan 2015
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2015 Dhupia, Rathour and Narayanan.


  • Dendritic morphology
  • Functional maps
  • HCN channel
  • Impedance
  • Resonance

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience


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