Abstract:
Background: Angiogenesis, or the formation of new blood vessels, is one of the body’s mechanisms to compensate for cerebral ischemia, and has been observed in the peri-infarct region following stroke. Vascular Endothelial Growth Factor (VEGF) is essential for angiogenesis and is expressed in ischemic cells. Our goal was to quantitatively measure the association patterns for one of VEGF’s receptors, VEGF Receptor-2 (VEGFR-2) on neurons in infarct, peri-infarct, and remote cortical regions of the non-human primate brain at three days following a focal ischemic infarct. The experiment assessed the hypothesis that neurons remote from the infarct may also have increased VEGFR-2 association at three days post-infarct. Methods: Cortical regions of seven adult squirrel monkeys (genus Saimiri) were mapped using standard
intracortical microstimulation techniques, three with no infarct (controls) and four with an infarct in the M1 hand region. Brains were paraffin-embedded, sectioned and immunostained for neurons (NeuN) and VEGFR-2. Stereological analysis was
conducted using Stereo Investigator (Microbrightfield) and significance determined. Results: A significantly higher association of VEGFR-2 to neurons occurred in the infarct, peri-infarct, PMv hand and M1 hindlimb areas, but not in M1 orofacial region or non-motor control areas, in experimental versus control animals (unpaired t-tests; p<0.05). Conclusion: From this information, it can be concluded that VEGFR-2 associates with neurons in discrete remote cortical regions that are related to the area of infarct. This suggests the possibility of a neuroprotective role for VEGFR-2 in remote motor areas in addition to angiogenesis in the peri-infarct and infarct regions.
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