Neuron-to-silicon junctions are an amazing tool for studying a variety of biological questions about how neurons connect together and how information is processed in their networks. By using a silicon based photoconductive stimulation technique that I developed with Yuki Goda at UCSD, we can stimulate groups of neurons, individual neurons, and even small components of individual neurons non-invasively. The magic ingredient is light.
PHOTOCONDUCTIVE STIMULATION
Neurons grown on pre-processed silicon wafers are readily amenable for photoconductive stimulation. As a voltage step is held across these silicon wafers, a targeted beam of light from a laser can be used to select individual neurons for depolarization. This has advantages over transistor array based stimulation techniques because stimulation sites are not constrained to discrete regions of the wafer. Virtually any neuron can be stimulated regardless of its spatial location. Furthermore, this technique has the added advantages of being relatively inexpensive and easy to manipulate.
Using this technology we have an opportunity to monitor, among many things, the short term and long term structural changes in the wiring of neurons in response to particular activity patterns.
RESOURCES
Colicos MA & Syed NI (2006).Neuronal networks and synaptic plasticity: understanding complex system dynamics by interfacing neurons with silicon technologies. J Exp Biol.Jun;209(Pt 12):2312-9. PDF
Goda Y. & Colicos MA (2006).Photoconductive stimulation of neurons cultured on silicon wafers.Nat Protoc;1(1):461-7. PubMed
