Current techniques that measure fluorescence in single cells are usually limited to a very small optical area, typically several tens of microns in diameter, or about the size of the optical field seen through a normal upright or inverted microscope. Wide field measurements have the potential to be used in many types of studies, ranging from examinations of the effects of long-range connections on the dynamics of neuronal activity, the cellular regulation of neuronal outgrowth, and the correlation between neuronal activity and behavior in unrestrained model organisms such as c. elegans. The PI plans to develop a technically accessible and ultimately inexpensive instrument that harnesses the light-gathering power and simplicity of contact fluorescence imaging (CFI) for wide field optical recordings in cultured neural networks, brain slices, and freely moving model organisms.
The goal is to build and test a prototype of a new type of CFI instrument, the first one designed specifically for neuroscientific applications. The instrument will be tested using genetically targeted fluorescent probes expressed in cultured cortical neurons as well as neurons and muscles in the nematode C. elegans. One of the main goals is to enable the first optical recordings of excitable cells during behavior in a freely moving organism.
The proposed instrument has the potential to facilitate research not only in C. elegans but also in cellular, systems, and developmental neuroscience in general. At the cellular level, the instrument could be combined with microfluidic devices and other spatial patterning methods for high-throughput testing of drugs and other biologically active substances in cell cultures. At the systems level, the new device could facilitate studies of the spatiotemporal dynamics of spontaneous and evoked neuronal activity at centimeter scale with single-neuron resolution, in some cases for the first time. A wide range of acute or cultured preparations could benefit from such an approach, including spinal cord, retina, whole ganglia, cultured hippocampal and cortical neurons, and slice or organotypic slice preparations.
Finally, the system should be quite inexpensive to build and maintain. It is envisioned that that the new device could become the imaging equivalent of a table-top centrifuge, vastly increasing the number of labs to which imaging is available.
