Scattered-light imaging in vivo tracks fast and slow processes of neurophysiological activation. Export

@article{citeulike:2838014, abstract = {We imaged fast optical changes associated with evoked neural activation in the dorsal brainstem of anesthetized rats, using a novel imaging device. The imager consisted of a gradient-index (GRIN) lens, a microscope objective, and a miniature charged-coupled device (CCD) video camera. We placed the probe in contact with tissue above cardiorespiratory areas of the nucleus of the solitary tract and illuminated the tissue with 780-nm light through flexible fibers around the probe perimeter. The focus depth was adjusted by moving the camera and microscope objective relative to the fixed GRIN lens. Back-scattered light images were relayed through the GRIN lens to the CCD camera. Video frames were digitized at 100 frames per second, along with tracheal pressure, arterial blood pressure, and electrocardiogram signals recorded at 1 kHz per channel. A macroelectrode placed under the GRIN lens recorded field potentials from the imaged area. Aortic, vagal, and superior laryngeal nerves were dissected free of surrounding tissue within the neck. Separate shocks to each dissected nerve elicited evoked electrical responses and caused localized optical activity patterns. The optical response was modeled by four distinct temporal components corresponding to putative physical mechanisms underlying scattered light changes. Region-of-interest analysis revealed image areas which were dominated by one or more of the different time-course components, some of which were also optimally recorded at different tissue depths. Two slow optical components appear to correspond to hemodynamic responses to metabolic demand associated with activation. Two fast optical components paralleled electrical evoked responses.}, address = {Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.}, author = {Rector, D. M. and Rogers, R. F. and Schwaber, J. S. and Harper, R. M. and George, J. S.}, citeulike-article-id = {2838014}, citeulike-linkout-0 = {http://dx.doi.org/10.1006/nimg.2001.0897}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/11697930}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=11697930}, doi = {10.1006/nimg.2001.0897}, issn = {1053-8119}, journal = {NeuroImage}, keywords = {bold, grin, intrinsic, method}, month = {November}, number = {5}, pages = {977--994}, posted-at = {2008-05-27 19:09:07}, priority = {2}, title = {Scattered-light imaging in vivo tracks fast and slow processes of neurophysiological activation.}, url = {http://dx.doi.org/10.1006/nimg.2001.0897}, volume = {14}, year = {2001} }

TY - JOUR ID - citeulike:2838014 L3 - citeulike-article-id:2838014 N2 - We imaged fast optical changes associated with evoked neural activation in the dorsal brainstem of anesthetized rats, using a novel imaging device. The imager consisted of a gradient-index (GRIN) lens, a microscope objective, and a miniature charged-coupled device (CCD) video camera. We placed the probe in contact with tissue above cardiorespiratory areas of the nucleus of the solitary tract and illuminated the tissue with 780-nm light through flexible fibers around the probe perimeter. The focus depth was adjusted by moving the camera and microscope objective relative to the fixed GRIN lens. Back-scattered light images were relayed through the GRIN lens to the CCD camera. Video frames were digitized at 100 frames per second, along with tracheal pressure, arterial blood pressure, and electrocardiogram signals recorded at 1 kHz per channel. A macroelectrode placed under the GRIN lens recorded field potentials from the imaged area. Aortic, vagal, and superior laryngeal nerves were dissected free of surrounding tissue within the neck. Separate shocks to each dissected nerve elicited evoked electrical responses and caused localized optical activity patterns. The optical response was modeled by four distinct temporal components corresponding to putative physical mechanisms underlying scattered light changes. Region-of-interest analysis revealed image areas which were dominated by one or more of the different time-course components, some of which were also optimally recorded at different tissue depths. Two slow optical components appear to correspond to hemodynamic responses to metabolic demand associated with activation. Two fast optical components paralleled electrical evoked responses. IS - 5 JF - NeuroImage SN - 1053-8119 AD - Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. EP - 994 TI - Scattered-light imaging in vivo tracks fast and slow processes of neurophysiological activation. VL - 14 SP - 977 KW - bold KW - grin KW - intrinsic KW - method AU - Rector, DM AU - Rogers, RF AU - Schwaber, JS AU - Harper, RM AU - George, JS PY - 2001/11// UR - http://dx.doi.org/10.1006/nimg.2001.0897 ER -