CCD VIDEO CAMERA FOR HIGH-SENSITIVITY LIGHT MEASUREMENTS IN FREELY BEHAVING ANIMALS

We developed a miniaturized, high-sensitivity camera that can be place d in areas of difficult access in freely behaving animals for neural t issue imaging. The device consists of a charged coupled device (CCD) c hip, a coherent image conduit and miniature light emitting diodes (LED s). An amplifier circuit is constructed on the camera chip and nine wi res are attached for external connections. Placement of LEDs around th e image conduit perimeter provides dark-field illumination, which incr eases detection of cellular-related light scattering changes and doubl es the depth-of-view over conventional reflectance imaging procedures. The device has been successfully used to record from several deep bra in structures, including the ventral medullary surface of sleeping and waking cats. The procedure allows assessment of light scattering chan ges that result from neural activity or detection of vital dyes to met abolic or voltage-induced activation. (C) 1997 Elsevier Science B.V.