Temporal dynamics and magnitude of the blood flow response at the optic disk in normal subjects during functional retinal flicker-stimulation
Autor: | Eric Logean, Benedetto Falsini, Charles E. Riva |
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Rok vydání: | 2004 |
Předmět: |
Adult
Male medicine.medical_specialty Optic Disk Optic disk Hemodynamics Laser Doppler Blood volume chemistry.chemical_compound Ophthalmology Laser-Doppler Flowmetry medicine Humans Retina Imaging Funzionale Nervo Ottico Settore MED/30 - MALATTIE APPARATO VISIVO General Neuroscience Retinal Blood flow Middle Aged Laser Doppler velocimetry Surgery medicine.anatomical_structure chemistry Regional Blood Flow Optic nerve Female sense organs Photic Stimulation |
Zdroj: | Neuroscience Letters. 356:75-78 |
ISSN: | 0304-3940 |
DOI: | 10.1016/j.neulet.2003.08.069 |
Popis: | 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. |
Databáze: | OpenAIRE |
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