Scanning laser-Doppler flowmetry of rat cerebral circulation during cortical spreading depression

TY - JOUR

T1 - Scanning laser-Doppler flowmetry of rat cerebral circulation during cortical spreading depression

AU - Nielsen, Alexander Norup

AU - Fabricius, Martin

AU - Lauritzen, Martin

PY - 2000/12/1

Y1 - 2000/12/1

N2 - Scanning laser-Doppler flowmetry (SLDF) generates two-dimensional images of blood flow. This study compared SLDF to conventional laser-Doppler flowmetry (LDF) in the cerebral circulation. Test stimuli were episodes of cortical spreading depression (CSD) elicited in brains of halothane anaesthetised rats (n = 9). The LDF instrument used two wavelengths of laser light to record relative changes of cerebral blood flow (CBF) up to an approximate depth of 250 μm (543 nm) and 500 μm (780 nm). Under resting conditions, SLDF images showed a heterogeneous pattern of flow in pial vessels with high flow rates in arterioles, and lower rates in venules and small vessels (<30 μm). Arterioles constituted about 6%, venules 12% and small vessels 2% of the image area, while approximately 80% were background with a laser-Doppler signal corresponding to zero calibration. During CSD, the relative increase of area was largest for small vessels and less for venules and arterioles. Similar changes were observed for blood flow in the three vessel structures. For both wavelengths of LDF, flow changes correlated with SLDF (r ≈ 0.7). In conclusion, SLDF provides images of flow in pial vessels and capillaries at, or just beneath the cortical surface. SLDF and LDF are complementary, but cannot substitute for one another as they measure flow in different layers of the cortex.

AB - Scanning laser-Doppler flowmetry (SLDF) generates two-dimensional images of blood flow. This study compared SLDF to conventional laser-Doppler flowmetry (LDF) in the cerebral circulation. Test stimuli were episodes of cortical spreading depression (CSD) elicited in brains of halothane anaesthetised rats (n = 9). The LDF instrument used two wavelengths of laser light to record relative changes of cerebral blood flow (CBF) up to an approximate depth of 250 μm (543 nm) and 500 μm (780 nm). Under resting conditions, SLDF images showed a heterogeneous pattern of flow in pial vessels with high flow rates in arterioles, and lower rates in venules and small vessels (<30 μm). Arterioles constituted about 6%, venules 12% and small vessels 2% of the image area, while approximately 80% were background with a laser-Doppler signal corresponding to zero calibration. During CSD, the relative increase of area was largest for small vessels and less for venules and arterioles. Similar changes were observed for blood flow in the three vessel structures. For both wavelengths of LDF, flow changes correlated with SLDF (r ≈ 0.7). In conclusion, SLDF provides images of flow in pial vessels and capillaries at, or just beneath the cortical surface. SLDF and LDF are complementary, but cannot substitute for one another as they measure flow in different layers of the cortex.

KW - Cerebral blood flow

KW - Cortical spreading depression

KW - Laser-Doppler flowmetry

KW - Laser-Doppler perfusion imaging

KW - Scanning laser-Doppler flowmetry

UR - http://www.scopus.com/inward/record.url?scp=0034515078&partnerID=8YFLogxK

U2 - 10.1159/000054084

DO - 10.1159/000054084

M3 - Journal article

C2 - 11146405

AN - SCOPUS:0034515078

SN - 1018-1172

VL - 37

SP - 513

EP - 522

JO - Journal of Vascular Research

JF - Journal of Vascular Research

IS - 6

ER -