Abstract View
R.L.Barbour; C.H.Schmitz; Y.Pei; R.Ansari; M.B.Holzer; B.Rivard; R.U.Muller; S.Schwartz-Giblin*
Physiology, SUNY Downstate Med. Ctr., Brooklyn, NY, USA
We describe the development of a dual-mode diffuse optical tomographic (DOT) imaging and EEG recording system suitable for the study of real-time neural and hemodynamic responses in freely moving rats. The system employs an umbilical of 16 optical fibers serving both for light delivery and its reemission that is overlaid on a second umbilical containing 16 recording micro-electrodes. Both data collection arrays are terminated in a precision-machined cap that is surgically attached to the skull. Free mobility is attained by suspending the umbilicals using an elastomeric cord that renders the unit neutrally buoyant. In addition, the unit employs a camera-LED based controlled commutator to avoid cumulated mechanical stress resulting from repeated circular animal movements. The camera unit also allows for precise video tracking of freely moving animals for comparison of neural and hemodynamic responses with behavior. Optical measurements are performed using laser diodes operating at 760 and 830 nm that provide for a time-multiplexed, frequency-encoded illumination scheme having a source-switching speed of approximately 90Hz. A timestamp is employed to achieve precise data synchrony between the EEG, optical and video data collection modes. Automated optical system set-up and control is achieved through a LabVIEW interface that provides for on-the-fly adjustment of gain control, data integrity checks and system calibration, among other functionalities. EEG recording is achieved using the Neuralynx electrophysiological recording system. Collected optical data can be processed either on-the-fly, to provide for real-time, or offline, volumetric imaging. The integrated system includes a comprehensive image formation, display and time-series analysis software suitable for processing each mode independently or in combination.
Citation:R.L. Barbour, C.H. Schmitz, Y. Pei, R. Ansari, M.B. Holzer, B. Rivard, R.U. Muller, S. Schwartz-Giblin. 4D FUNCTIONAL IMAGING IN FREELY MOVING RATS Program No. 921.13. 2005 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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