Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Carbon nanotubes might improve neuronal performance by favouring electrical shortcuts


Carbon nanotubes have been applied in several areas of nerve tissue engineering to probe and augment cell behaviour, to label and track subcellular components, and to study the growth and organization of neural networks. Recent reports show that nanotubes can sustain and promote neuronal electrical activity in networks of cultured cells, but the ways in which they affect cellular function are still poorly understood. Here, we show, using single-cell electrophysiology techniques, electron microscopy analysis and theoretical modelling, that nanotubes improve the responsiveness of neurons by forming tight contacts with the cell membranes that might favour electrical shortcuts between the proximal and distal compartments of the neuron. We propose the ‘electrotonic hypothesis’ to explain the physical interactions between the cell and nanotube, and the mechanisms of how carbon nanotubes might affect the collective electrical activity of cultured neuronal networks. These considerations offer a perspective that would allow us to predict or engineer interactions between neurons and carbon nanotubes.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: The effect of nanotubes (CNTs) on neuronal excitability.
Figure 2: Planar electrically conductive surfaces do not affect after-potential neuronal excitability.
Figure 3: Effect of conductivity and nanoscale features on neurons.
Figure 4: The electrotonic hypothesis.
Figure 5: The ultrastructural interaction between multi-wall nanotubes and neurons.
Figure 6: Network-level correlate of ADP in single neurons: model and experiment.


  1. 1

    Silva, G. A. Neuroscience nanotechnology: progress, opportunities and challenges. Nature Rev. Neurosci. 7, 65–74 (2006).

    Article  Google Scholar 

  2. 2

    Silva, G. A. Nanotechnology approaches for drug and small molecule delivery across the blood brain barrier. Surg. Neurol. 67, 113–116 (2007).

    Article  Google Scholar 

  3. 3

    Fortina, P., Kricka, L. J., Surrey, S. & Grodzinski, P. Nanobiotechnology: the promise and reality of new approaches to molecular recognition. Trends Biotechnol. 23, 168–173 (2005).

    Article  Google Scholar 

  4. 4

    Parpura, V. Instrumentation: carbon nanotubes on the brain. Nature Nanotech. 3, 384–385 (2008).

    Article  Google Scholar 

  5. 5

    Krishnan, A., Dujardin, E., Ebbesen, T. W., Yianilos, P. N. & Treacy, M. M. J. Young's modulus of single-walled nanotubes. Phys. Rev. B 58, 14013–14019 (1998).

    Article  Google Scholar 

  6. 6

    Harrison, B. S. & Atala, A. Carbon nanotube applications for tissue engineering. Biomaterials 28, 344–353 (2007).

    Article  Google Scholar 

  7. 7

    Giugliano, M., Prato, M. & Ballerini, L. Nanomaterial/neuronal hybrid system for functional recovery of the CNS. Drug Discov. Today: Disease Models, doi: 10.1016/j.ddmod.2008.07.004 (2008).

  8. 8

    Keefer, E. W., Botterman, B. R., Romero, M. I., Rossi, A. F. & Gross, G. W. Carbon nanotube coating improves neuronal recordings. Nature Nanotech. 3, 434–439 (2008).

    Article  Google Scholar 

  9. 9

    Ballerini, L. Bridging multiple levels of exploration: towards a neuroengineering-based approach to physiological and pathological problems in neuroscience. Frontiers Neurosci. 2, 24–25 (2008).

    Article  Google Scholar 

  10. 10

    Mazzatenta, A. et al. Interfacing neurons with carbon nanotubes: electrical signal transfer and synaptic stimulation in cultured brain circuits. J. Neurosci. 27, 6931–6936 (2007).

    Article  Google Scholar 

  11. 11

    Mattson, M. P., Haddon, R. C. & Rao A. M. Molecular functionalization of carbon nanotubes use as substrates for neuronal growth. J. Mol. Neurosci. 14, 175–182 (2000).

    Article  Google Scholar 

  12. 12

    Hu, H., Ni, Y., Montana, V., Haddon, R. C. & Parpura, V. Chemically functionalized carbon nanotubes as substrates for neuronal growth. Nano Lett. 4, 507–511 (2004).

    Article  Google Scholar 

  13. 13

    Hu, H. et al. Polyethyleneimine functionalized single-walled carbon nanotubes as a substrate for neuronal growth. J. Phys. Chem. B 109, 4285–4289 (2005).

    Article  Google Scholar 

  14. 14

    Lovat, V. et al. Carbon nanotube substrates boost neuronal electrical signaling. Nano Lett. 5, 1107–1110 (2005).

    Article  Google Scholar 

  15. 15

    Galvan-Garcia, P. et al. Robust cell migration and neuronal growth on pristine carbon nanotube sheets and yarns. J. Biomater. Sci. Polym. Ed. 18, 1245–1261 (2007).

    Article  Google Scholar 

  16. 16

    Schaefer, A. T., Larkum, M. E., Sakmann, B. & Roth, A. Coincidence detection in pyramidal neurons is tuned by their dendritic branching pattern. J. Neurophysiol. 89, 3143–3154 (2003).

    Article  Google Scholar 

  17. 17

    Kirckpatrick, S. Percolation and conduction. Rev. Mod. Phys. 45, 574–588 (1972).

    Article  Google Scholar 

  18. 18

    Larkum, M. E., Kaiser, K. M. & Sakmann, B. Calcium electrogenesis in distal apical dendrites of layer 5 pyramidal cells at a critical frequency of back-propagating action potentials. Proc. Natl Acad. Sci. USA 96, 14600–14604 (1999).

    Article  Google Scholar 

  19. 19

    Larkum, M. E., Waters, J., Sakmann, B. & Helmchen, F. Dendritic spikes in apical dendrites of neocortical layer 2/3 pyramidal neurons. J. Neurosci. 27, 8999–9008 (2007).

    Article  Google Scholar 

  20. 20

    Seamans, J. K., Gorelova, N. A. & Yang, C. R. Contributions of voltage-gated Ca2+ channels in the proximal versus distal dendrites to synaptic integration in prefrontal cortical neurons. J. Neurosci. 17, 5936–5948 (1997).

    Article  Google Scholar 

  21. 21

    Young, C. E. & Yang, C. R. Dopamine D1/D5 receptor modulates state-dependent switching of soma-dendritic Ca2+ potentials via differential protein kinase A and C activation in rat prefrontal cortical neurons. J. Neurosci. 24, 8–23 (2004).

    Article  Google Scholar 

  22. 22

    Markram, H., Helm, P. J. & Sakmann, B. Dendritic calcium transients evoked by single back-propagating action potentials in rat neocortical pyramidal neurons. J. Physiol. 485, 1–20 (1995).

    Article  Google Scholar 

  23. 23

    Nyberg, T., Shimada, A. & Torimitsu, K. Ion conducting polymer microelectrodes for interfacing with neural networks. J. Neurosci. Methods 160, 16–25 (2007).

    Article  Google Scholar 

  24. 24

    Gelain, F., Bottai, D., Vescovi, A. & Zhang, S. Designer self-assembling peptide nanofiber scaffolds for adult mouse neural stem cell 3-dimensional cultures. PLoS ONE 1, e119 (2006).

    Article  Google Scholar 

  25. 25

    Larkum, M. E., Senn, W. & Lüscher, H. R. Top-down dendritic input increases the gain of layer 5 pyramidal neurons. Cereb. Cortex 14, 1059–1070 (2004).

    Article  Google Scholar 

  26. 26

    Horowitz, P. & Hill, W. The Art of Electronics 2nd edn (Cambridge Univ. Press, 1989).

    Google Scholar 

  27. 27

    Robinson, D. A. The electrical properties of metal microelectrodes. Proc. IEEE 56, 1065–1071 (1968).

    Article  Google Scholar 

  28. 28

    Georgakilas, V. et al. Organic functionalization of carbon nanotubes. J. Am. Chem. Soc. 124, 760–761 (2002).

    Article  Google Scholar 

  29. 29

    Peters, A., Palay, S. L. & Webster, H. F. The Fine Structure of the Nervous System (Oxford Univ. Press, 1991).

    Google Scholar 

  30. 30

    Pastorin, G. et al. Double functionalization of carbon nanotubes for multimodal drug delivery. Chem. Commun. 11, 1182–1184 (2006).

    Article  Google Scholar 

  31. 31

    Markram, H., Lübke, J., Frotscher, M. & Sakmann, B. Regulation of synaptic efficacy by coincidence of postsynaptic APs and EPSPs. Science 275, 213–215 (1997).

    Article  Google Scholar 

  32. 32

    Giugliano, M., Darbon, P., Arsiero, M., Lüscher, H. R. & Streit, J. Single-neuron discharge properties and network activity in dissociated cultures of neocortex. J. Neurophysiol. 92, 977–996 (2004).

    Article  Google Scholar 

  33. 33

    Christie, B. R., Eliot, L. S., Ito, K., Miyakawa, H. & Johnston, D. Different Ca2+ channels in soma and dendrites of hippocampal pyramidal neurons mediate spike-induced Ca2+ influx. J. Neurophysiol. 73, 2553–2557 (1995).

    Article  Google Scholar 

  34. 34

    Magee, J. C. & Carruth, M. Dendritic voltage-gated ion channels regulate the action potential firing mode of hippocampal CA1 pyramidal neurons. J. Neurophysiol. 82, 1895–1901 (1999).

    Article  Google Scholar 

  35. 35

    Kampa, B. M. & Stuart, G. J. Calcium spikes in basal dendrites of layer 5 pyramidal neurons during action potential bursts. J. Neurosci. 26, 7424–7432 (2006).

    Article  Google Scholar 

Download references


We are grateful to A. Roth, A. Schaefer and I. Riachi for helpful discussions, K.-H. Boven for providing ITO substrates, C. Zacchigna for assistance with tissue cultures, C. Gamboz and A. Mazzatenta for TEM procedures, and to L. Sivilotti for comments on the previous version of this manuscript. Financial support from EPFL (to M.G., L.G. and H.M.), EU (NEURONANO-NMP4-CT-2006-031847 to M.P., M.G., H.M. and L.B.), CARIPLO (to F.G.), Fondazione Alberto and Kathleen Casali, and Progetto D4 Area Science Park mobility program (to E.C.) is gratefully acknowledged.

Author information



Corresponding author

Correspondence to Laura Ballerini.

Supplementary information

Supplementary Information

Supplementary Information (PDF 877 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Cellot, G., Cilia, E., Cipollone, S. et al. Carbon nanotubes might improve neuronal performance by favouring electrical shortcuts. Nature Nanotech 4, 126–133 (2009).

Download citation

Further reading


Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research