A diagram of system components shows a 780-nm laser
diode array light source (L.S.) projecting light into flexible fiber optics mounted around the perimeter of a GRIN lens. The GRIN lens was placed in contact with the dorsal medulla, which collected backscattered light from the rat dorsal medulla, and formed an image through a microscope objective (M.O.) onto a CCD camera. A change in the focal plane was achieved by moving the CCD camera and objective relative to the GRIN lens, which remained fixed in position. (Rector at al 2005)
Lobster’s leg nerve
Reflected responses (top shaded trace) could be detected with a single trail. A measurement (top black trace) from 100 averages was also recorded for reference. The bottom black trace was the electrophysiological response. The vertical line indicates the time of stimulation. (Yao et al., 2005)
Reflectance image at 578 nm of somatosensory cortex through thinned skull. A. Before exchange transfusion with fluorocarbon. Ves- sels are observed clearly. B. After transfusion of hematocrit 8%. The contrast between vessel and parenchyma decreases. Scale bar shows 500 mm. The box 500=500 mm2 . designates the area of quantitation of the intrinsic optical signal. (Tamura et al, 2001)
The stimulus begins within the red-outlined frame and is 100 ms in duration. A rapid optical response can be seen toward the bottom of the image within 30 ms (3 frames) after the stimulus, and a long-lasting light intensity increase (blue color) begins on the 18th frame and persists for nearly the entire equence.
(Rector et al 2001)
Fast IOS:
- -Mainly caused by ions movement and fast metabolic reactions
-- Frequently covered by “normal” IOS in case of in vivo imaging of mammals brain
- -Have a maximum at the near infrared part of spectrum (NIRS human imaging)
- - One of the main component of human EROS (evoked response optical signal)