Here we propose to develop a multi-functional nano-pipette (NP) for in vivo endoscopic imaging, combined with electrophysiological recording from deep cortical layers or deep brain structures. Using this NP, we plan to study neuronal mechanisms of information processing across cortical layers and from deep brain nuclei. Functional maps in the barrel cortex of rats and visual cortex of behaving monkeys are well established nowadays and can be demonstrated in 2D, using functional imaging techniques such as optical imaging of intrinsic signals (OI-IS), with high spatial resolution, or voltage-sensitive dye imaging (VSDI) with high spatio-temporal resolution. However, imaging functional maps in 3D has not yet been fully achieved due to the inability of modern in vivo imaging techniques to resolve neuronal activity at high spatio-temporal resolution from deep layers of the cerebral cortex. For the same reasons, imaging from deep brain structures using VSDI or OI-IS is not possible currently. Here we propose to address this problem by combining recent developments in the field on nanotechnology and in real time imaging techniques in vivo. Recently, Prof. Zeev Zalevsky and his laboratory have developed the technology that enables generation of fibers similar to photonic crystal fibers (PCF), having internal metal wires. Those fibers are generated by tapering silica pre-forms with desired cross section into which the wires are pre-inserted. This tapering of the pre-form, obtained without losing its internal geometry, produces short, thin nano-pipettes that transmit light and electrical signals to appropriate sensors. Furthermore, the Zalevsky laboratory has developed algorithms to amplify the low resolution inherent in such a system. Using this technology and expertise, in combination with Dr. Hamutal Slovin's imaging expertise, we propose to fabricate a tapered pre-form containing optical and electrical fibers (Specific Aim #1) and test its applicability on small artificial targets in vitro and in vivo (Specific Aim #2). Finally, we will determine whether this device can be used for brain imaging by testing it in vivo on the barrel cortex and deep brain nuclei of anesthetized rats through functional imaging, namely OI-IS and VSDI (Specific Aim #3). If successful, our nano-pipette is expected to revolutionize existing imaging capabilities and will enable new insights into the neural mechanisms underlying visual perception and higher cognitive functions.
We propose to develop a nanopipette (probe), which will be inserted into the cortical surface of the brain and will enable simultaneous imaging and electrophysiological recording from deep cortical layers or deep brain nuclei. If successful, the outcomes of this project will revolutionize existing imaging capabilities and will enable new insights into the neural mechanisms underlying visual perception and higher cognitive functions.
