Journal
NEUROSCIENCE LETTERS
Volume 356, Issue 2, Pages 75-78Publisher
ELSEVIER IRELAND LTD
DOI: 10.1016/j.neulet.2003.08.069
Keywords
functional activity; laser Doppler flowmetry; neurovascular coupling; flicker stimulation; optic nerve blood flow
Categories
Ask authors/readers for more resources
Near-infrared laser Doppler flowmetry was applied in 15 normal volunteers to record the time course and magnitude of changes in the velocity (Vel), volume (Vol) and flow (F) of blood and tissue reflectance (R) at the optic disk in response to 40 and 50 s of increased retinal neural activity. This activity was evoked by diffuse luminance flicker of the retinal posterior pole. After 20 s of flicker, the group averages of Vel, Vol, and F were significantly higher than at baseline (pre-flicker) by 12, 24 and 38%. Time constants of the increases in Vel, Vol, and F were 3.4, 12.7 and 9.1 s, respectively. The group average change in R of 1% was not significant. However, in one subject, 15 recordings from the same site of the optic disk showed a significant increase in R of 8%, with a time course similar to that of Vol. Our findings show that, in the human optic nerve, a white matter tissue, the temporal dynamics and magnitude of the response of blood flow to an increase in retinal neural activity are similar to those reported for brain gray matter. Furthermore, although the R-response could be due, in part, to changes in blood volume, other factors, such as activity-evoked tissue scattering changes, may also affect this response. (C) 2003 Elsevier Ireland Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available