In vivo rat brain measurements of changes in signal intensity depth profiles as a function of temperature using wide-field optical coherence tomography.

In our previous study, we used optical coherence tomography (OCT) and reported an increase in signal intensity of depth profiles between euthanasia injection and cardiac arrest (CA), demonstrating the potential as a tool for monitoring/diagnosing brain tissue viability [Appl. Opt.48, 4354 (2009)]. Here, for the first time to our knowledge, we measured three-dimensional (3D) OCT images through a thinned skull changing temperatures in the rat brain. The measurements were made at 10 min intervals for 210 min to evaluate correlations of temperature with heart rate and ratios of signal intensity (RSI). The 3D image area was 4 mm × 4 mm × 2.8 mm. When the temperature was decreased from 28°C to 18°C to reduce tissue viability, the heart rate was found to decrease with an increase in RSI. Negative correlation coefficients (CCs) between temperatures and RSIs, and between heart rate and RSIs, were obtained. This indicates that OCT signals increase with reductions of viability caused by decreases in heart rates and temperatures in tissues. These observations correspond to estimations obtained by multiwavelength diffuse reflectance spectroscopy [Appl. Opt.47, 4164 (2008)]. CCs and stationary RSIs would depend upon measured positions in tissues. Without injections for euthanasia, a similar rapid increase in RSI has also been measured before CA.

[1]  Toshio Yanagida,et al.  In vivo imaging of the rat cerebral microvessels with optical coherence tomography. , 2004, Clinical hemorheology and microcirculation.

[2]  B. Bouma,et al.  Handbook of Optical Coherence Tomography , 2001 .

[3]  N Tsurumachi,et al.  Wide-field optical coherence tomography: imaging of biological tissues. , 2002, Applied optics.

[4]  N. Kalia,et al.  Effects of Hypothermia and Rewarming on the Mucosal Villus Microcirculation and Survival After Rat Intestinal Ischemia–Reperfusion Injury , 2002, Annals of surgery.

[5]  S. Arora,et al.  Diagnosis and treatment of hypothermia. , 2004, American family physician.

[6]  Satoko Kawauchi,et al.  Light scattering change precedes loss of cerebral adenosine triphosphate in a rat global ischemic brain model , 2009, Neuroscience Letters.

[7]  M. Tanifuji,et al.  Implementation of optical coherence tomography (OCT) in visualization of functional structures of cat visual cortex , 2002 .

[8]  S G Lomber,et al.  Translaminar differentiation of visually guided behaviors revealed by restricted cerebral cooling deactivation. , 2000, Cerebral cortex.

[9]  H. Kadono,et al.  Novel functional imaging technique from brain surface with optical coherence tomography enabling visualization of depth resolved functional structure in vivo , 2003, Journal of Neuroscience Methods.

[10]  Eng H. Lo,et al.  Neurological diseases: Mechanisms, challenges and opportunities in stroke , 2003, Nature Reviews Neuroscience.

[11]  A. Rezai,et al.  A feasibility study of optical coherence tomography for guiding deep brain probes , 2006, Journal of Neuroscience Methods.

[12]  I. Nishidate,et al.  Measurement of signal intensity depth profiles in rat brains with cardiac arrest using wide-field optical coherence tomography. , 2009, Applied optics.

[13]  Satoko Kawauchi,et al.  Simultaneous measurement of changes in light absorption due to the reduction of cytochrome c oxidase and light scattering in rat brains during loss of tissue viability. , 2008, Applied optics.

[14]  H. Higashi,et al.  Membrane dysfunction induced by in vitro ischemia in rat hippocampal CA1 pyramidal neurons. , 1999, Journal of neurophysiology.

[15]  Razvan Dabu,et al.  Quadrature fringes wide-field optical coherence tomography and its applications to biological tissues , 2007 .

[16]  Angelika Unterhuber,et al.  Imaging ex vivo healthy and pathological human brain tissue with ultra-high-resolution optical coherence tomography. , 2005, Journal of biomedical optics.

[17]  Nitish V Thakor,et al.  Post-cardiac arrest temperature manipulation alters early EEG bursting in rats. , 2008, Resuscitation.

[18]  A. Cowey,et al.  Imaging ex vivo and in vitro brain morphology in animal models with ultrahigh resolution optical coherence tomography. , 2004, Journal of biomedical optics.

[19]  K. Arai,et al.  Experimental models for analysis of oligodendrocyte pathophysiology in stroke , 2009, Experimental & Translational Stroke Medicine.

[20]  K. Hossmann.  Viability thresholds and the penumbra of focal ischemia , 1994, Annals of neurology.

[21]  R. David Andrew,et al.  Intrinsic Optical Signaling Denoting Neuronal Damage in Response to Acute Excitotoxic Insult by Domoic Acid in the Hippocampal Slice , 1998, Neurobiology of Disease.

[22]  Yi Zhang,et al.  Tightly coupled brain activity and cerebral ATP metabolic rate , 2008, Proceedings of the National Academy of Sciences.

[23]  D. Ts'o,et al.  Cortical functional architecture and local coupling between neuronal activity and the microcirculation revealed by in vivo high-resolution optical imaging of intrinsic signals. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[24]  A. Ascenzi,et al.  Technique for Dissection and Measurement of Refractive Index of Osteones , 1959, The Journal of biophysical and biochemical cytology.

[25]  J. Schuman,et al.  Optical coherence tomography. , 2000, Science.

[26]  J G Fujimoto,et al.  Depth-resolved imaging of functional activation in the rat cerebral cortex using optical coherence tomography. , 2006, Optics letters.

[27]  J. Duker,et al.  In vivo measurement of retinal physiology with high-speed ultrahigh-resolution optical coherence tomography. , 2006, Optics letters.