[Abstract Title]. - Society for Neuroscience

CYP450 epoxygenase and inward rectifier potassium channels to test whether these pathways,
acting partly in parallel, could fully account for the blood flow response to neuronal activation.
Cerebral blood flow (CBF) and oxygenation over the somatosensory cortex were measured
during electrical forepaw stimulation in rats using a combined laser doppler/spectroscopy probe
through a superfused cranial window. Somatosensory evoked potentials (SEP) were recorded as
a correlate of neuronal activity. The CBF response was largely reduced with stable SEP during
combined inhibition of NO synthase, cyclooxygenase, adenosine receptors and CYP450
epoxygenase. Additional inhibition of inward rectifier potassium channels did not lead to a
significant further reduction of the CBF response. Despite significant reduction of the CBF
response, no deoxygenation could be detected. In summary, the NO, adenosine, cyclooxygenase,
CYP450 epoxygenase and inward rectifier potassium channel pathways together account for
approximately two third of functional hyperemia in the rat somatosensory cortex. As yet
unidentified additional pathways might be involved in coupling neuronal activity to regional
cerebral blood flow. In rat somatosensory cortex, only one third of the blood flow increase is
required to prevent relative hypoxia during increased neuronal activity.
Disclosures: C. Leithner , None; G. Royl, None; N. Offenhauser, None; M. Füchtemeier,
None; M. Kohl-Bareis, None; A. Villringer, None; U. Dirnagl, None; U. Lindauer, None.
Poster
286. Imaging the Nervous System
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 286.11/QQ51
Topic: E.09.c. Blood brain barrier
Support: DOD BC050006
Title: Permeability measurements at the blood-brain and blood-tumor barrier using different
molecular weight fluorescent markers
Authors: *R. MITTAPALLI 1 , K. A. BOHN 2 , J. M. EGBERT 2 , V. K. MANDA 2 , V.
RUDRARAJU 2 , K. S. TASKAR 2 , J. A. GAASCH 2 , Q. R. SMITH 2 , P. R. LOCKMAN 2 ;
1 TTU HSC, Amarillo,, TX; 2 Pharmaceut. Sci., Texas Tech. Univ. HSC, Sch. of Pharm.,
Amarillo, TX
Abstract: Introduction: The unique anatomical structure of the brain neurovasculature limits
chemotherapeutic distribution into normal brain and to a lesser extent, brain tumors. While there
are documented vascular permeability differences between tumor and normal brain, less is
known about permeability changes in various tumor regions. Therefore, we developed a novel