Intracortical Microcirculatory Change Induced by Anesthesia in Rat Somatosensory Cortex

Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 662)


The present study aimed to characterize microcirculatory responses to anesthesia in brain tissue. With multi-photon excitation fluorescence microscopy, intra-cortical capillary dimension and red blood cell (RBC) flow were successfully visualized up to a depth of ∼0.6 mm from the cortical surface in rats anesthetized with either isoflurane or α-chloralose. We observed that the diameter of the major cerebral artery was ∼100 µm under isoflurane, but ∼75 µm under α-chloralose. The capillary diameter was observed to be larger under α-chloralose than isoflurane: 5.1 ± 1.2 µm vs. 4.8 ± 1.1 µm, respectively. A significant difference in the mean RBC speed measured in single capillaries was observed: 0.4 ± 0.4 mm/s under α-chloralose vs. 1.5 ± 0.4 mm/s under isoflurane. In agreement with these observations, arterio-venous transit-time and laser-Doppler flowmetry consistently showed a significant reduction of the RBC and plasma blood speed under α-chloralose relative to isoflurane. These findings may indicate that local blood flow regulatory mechanisms exist at the capillary level for the balance of oxygen supply and demand induced by anesthesia in the brain tissue.


Cerebral Blood Flow Cortical Surface Single Capillary Baseline Cerebral Blood Flow Tissue Oxygen Level 



This work was partially supported by KAKENHI (#19800065).


  1. 1.
    Ndubuizu, O., LaManna, J. C., 2007, Brain tissue oxygen concentration measurements, Antioxid Redox Signal. 9:1207–1219.PubMedCrossRefGoogle Scholar
  2. 2.
    Masamoto, K., Kim, T., Fukuda, M., Wang, P., Kim, S. G., 2007, Relationship between neural, vascular, and BOLD signals in isoflurane-anesthetized rat somatosensory cortex, Cereb Cortex. 17:942–950.PubMedCrossRefGoogle Scholar
  3. 3.
    Ueki, M., Linn, F., Hossmann, K. A., 1988, Functional activation of cerebral blood flow and metabolism before and after global ischemia of rat brain, J Cereb Blood Flow Metab. 8:486–494.PubMedGoogle Scholar
  4. 4.
    Lee, S. P., Duong, T. Q., Yang, G., Iadecola, C., Kim, S. G., 2001, Relative changes of cerebral arterial and venous blood volumes during increased cerebral blood flow: implications for BOLD fMRI, Magn Reson Med. 45:791–800.PubMedCrossRefGoogle Scholar
  5. 5.
    Maekawa, T., Tommasino, C., Shapiro, H. M., Keifer-Goodman, J., Kohlenberger, R. W., 1986, Local cerebral blood flow and glucose utilization during isoflurane anesthesia in the rat, Anesthesiology. 65:144–151.PubMedCrossRefGoogle Scholar
  6. 6.
    Lenz, C., Frietsch, T., Futterer, C., Rebel, A., van Ackern, K., Kuschinsky, W., Waschke, K. F., 1999, Local coupling of cerebral blood flow to cerebral glucose metabolism during inhalational anesthesia in rats: desflurane versus isoflurane, Anesthesiology. 91:1720–1723.PubMedCrossRefGoogle Scholar
  7. 7.
    Kleinfeld, D., Mitra, P. P., Helmchen, F., Denk, W., 1998, Fluctuations and stimulus-induced changes in blood flow observed in individual capillaries in layers 2 through 4 of rat neocortex, Proc Natl Acad Sci U S A. 95:15741–15746.PubMedCrossRefGoogle Scholar
  8. 8.
    Hudetz, A. G., 1997, Blood flow in the cerebral capillary network: a review emphasizing observations with intravital microscopy, Microcirculation. 4:233–252.PubMedCrossRefGoogle Scholar
  9. 9.
    Masamoto, K., Kershaw, J., Ureshi, M., Takizawa, N., Kobayashi, H., Tanishita, K., Kanno, I., 2007, Apparent diffusion time of oxygen from blood to tissue in rat cerebral cortex: implication for tissue oxygen dynamics during brain functions, J Appl Physiol. 103:1352–1358.PubMedCrossRefGoogle Scholar
  10. 10.
    Masamoto, K., Vazquez, A., Wang, P., Kim, S. G., 2008, Trial-by-trial relationship between neural activity, oxygen consumption, and blood flow responses, Neuroimage. 40:442–450.PubMedCrossRefGoogle Scholar
  11. 11.
    Hou, H., Grinberg, O. Y., Taie, S., Leichtweis, S., Miyake, M., Grinberg, S., Xie, H., Csete, M., Swartz, H. M., 2003, Electron paramagnetic resonance assessment of brain tissue oxygen tension in anesthetized rats, Anesth Analg. 96:1467–1472.PubMedCrossRefGoogle Scholar
  12. 12.
    Inoue, K., Tomita, M., Fukuuchi, Y., Tanahashi, N., Kobari, M., Takao, M., Takeda, H., Yokoyama, M., 2003, Dynamic observation of oxygenation-induced contraction of and transient fiber-network formation-disassembly in cultured human brain microvascular endothelial cells, J Cereb Blood Flow Metab. 23:821–828.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Molecular Imaging Center, National Institute of Radiological SciencesChibaJapan

Personalised recommendations