Transcript Slide 1
Building Neural Networks on Carbon Nanotube Substrates Weijian Yang Department of Electrical Engineering and Computer Sciences University of California, Berkeley, CA, 94720, USA From Neuron to Neural Networks How do the neurons connect with each other to form a network? http://www.nih.gov/news/research_ma tters/july2006/07142006gene.htm 3 um http://www.joejoe.org/forum/i ndex.php?showtopic=7945 150 um Ref. 1, 2 UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 2 Outline 1. Nano carbontubes boost neuronal electrical signaling Viviane Lovat, et.al. Nano Lett., 5, 1107, 2005. 2. Engineering the neural network with patterned nano carbontubes substrates. Tamir Gabay, et.al. Physica A, 350, 611, 2005. 3. Outreach Understanding the brain, from neuron to mind. Harvard Magazine, edited by Courtney Humphries, May 2009. UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 3 Carbon Nanotubes as Substrates Why carbon nanotubes? Surface texture at the scale of ~10 to ~100 nm, aspect ratio similar to the nerve fiber. High electrical conductivity. Strong mechanical strength. Chemical functionalization. Good biocompatibility! Ref. 1-4 UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 4 Boost Neuronal Electrical Signal Hippocampal neuron growing on dispersed MWCNT in culture medium. Ref. 1 UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 5 Boost Neuronal Electrical Signal Spontaneous postsynaptic current Membrane potential Ref. 1 Improve neural signal transfer. Increase network activity. Reinforce electrical coupling between neurons. UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 6 Pattern the Neuron Network catalyst 150 um MWCNT Ref. 2 UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 7 Network Evolution 150 um 100 um One hour after cell deposition After 96 hours Ref. 2 Neurons’ surface mobility and selective adhesion are the driving mechanism for the well organized placement at the CNT sites. UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 8 Network Evolution 96 hours A single link is formed between the two nearest neighbors. 128 hours Connection is reinforced with respect to time. 150 hours A bundle is eventually formed to establish a tensed link between two islands. 150 um Ref. 2 UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 9 Summary Carbon nanotubes are highly biocompatible for neural network. (surface morphology, electrical, mechanical and chemical properties.) Well defined engineered cultured neural systems can be formed on high density carbon nanotube islands. A powerful platform to study neuronal adhesion, neurite outgrowth, and the neural network. UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 10 Outreach Nanowire is also a good candidate for the research into neural network. (especially in electrical, chemical, and biological signal detection.) Ref. 5, 6 UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 11 Reference 1. Viviane Lovat, et.al, “Nano Carbontubes Boost Neuronal Electrical Signaling,” Nano Lett., 5, 1107, 2005. 2. Tamir Gabay, et.al, “Engineering the Neural Network with Patterned Nano Carbontubes Substrates,” Physica A, 350, 611, 2005. 3. Miguel A. Correa-Duarte, et. al, “Fabrication and Biocompatibility of Carbon NanotubeBased 3D Networks as Scaffolds for Cell Seeding and Growth,” Nano Lett., 4, 2233, 2004. 4. Hui Hu, et. al., “Chemically Functionalized Carbon Nanotubes as Substrates for Neuronal Growth,” Nano Lett., 4, 507, 2004. 5. Fernando Patolsky, et. al. “Detection, Stimulation, and Inhibition of Neuronal Signals with High-Density Nanowire Transistor Arrays,” Science, 313, 1100, 2006. 6. “Understanding the brain, from neuron to mind,” Harvard Magazine, edited by Courtney Humphries, May 2009. UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 12 Thank you! Thank you! UC Berkeley EE 235 Presentation 2 Weijian Yang May 4, 2009 13