TY - JOUR
T1 - Temporal dynamics of brain tissue nitric oxide during functional forepaw stimulation in rats
AU - Buerk, Donald G.
AU - Ances, Beau M.
AU - Greenberg, Joel H.
AU - Detre, John A.
N1 - Funding Information:
This work was supported by EY09269, MH12078, MH59934, and NS337859 from the NIH.
PY - 2003
Y1 - 2003
N2 - We report the first dynamic measurements of tissue nitric oxide (NO) during functional activation of rat somatosensory cortex by electrical forepaw stimulation. Cortical tissue NO was measured electrochemically with rapid-responding recessed microelectrodes (tips <10 μm). Simultaneous blood flow measurements were made by laser-Doppler flowmetry (LDF). NO immediately increased, reaching a peak 125.5 ± 32.8 (SE) nM above baseline (P < 0.05) within 400 ms after stimulus onset, preceding any LDF changes, and then returned close to prestimulus levels after 2 s (123 signal-averaged trials, 12 rats). Blood flow began rising after a 1-s delay, reaching a peak just before electrical stimulation was ended at t = 4 s. A consistent poststimulus NO undershoot was observed as LDF returned to baseline. These findings complement our previous study (B. M. Ances et al., 2001, Neurosci. Lett. 306, 106-110) in which a transient decrease in rat somatosensory cortex tissue oxygen partial pressure was found to precede blood flow increases during functional activation.
AB - We report the first dynamic measurements of tissue nitric oxide (NO) during functional activation of rat somatosensory cortex by electrical forepaw stimulation. Cortical tissue NO was measured electrochemically with rapid-responding recessed microelectrodes (tips <10 μm). Simultaneous blood flow measurements were made by laser-Doppler flowmetry (LDF). NO immediately increased, reaching a peak 125.5 ± 32.8 (SE) nM above baseline (P < 0.05) within 400 ms after stimulus onset, preceding any LDF changes, and then returned close to prestimulus levels after 2 s (123 signal-averaged trials, 12 rats). Blood flow began rising after a 1-s delay, reaching a peak just before electrical stimulation was ended at t = 4 s. A consistent poststimulus NO undershoot was observed as LDF returned to baseline. These findings complement our previous study (B. M. Ances et al., 2001, Neurosci. Lett. 306, 106-110) in which a transient decrease in rat somatosensory cortex tissue oxygen partial pressure was found to precede blood flow increases during functional activation.
KW - Cerebral blood flow
KW - Functional activation
KW - Laser-Doppler flowmetry
KW - Nitric oxide
KW - Nitric oxide microelectrode
KW - Nitric oxide synthase
UR - http://www.scopus.com/inward/record.url?scp=0037227492&partnerID=8YFLogxK
U2 - 10.1006/nimg.2002.1314
DO - 10.1006/nimg.2002.1314
M3 - Article
C2 - 12507439
AN - SCOPUS:0037227492
VL - 18
SP - 1
EP - 9
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
IS - 1
ER -