CBF change evoked by somatosensory activation measured by laser-Doppler flowmetry: independent evaluation of RBC velocity and RBC concentration.
Jpn J Physiol
; 49(3): 289-96, 1999 Jun.
Article
em En
| MEDLINE
| ID: mdl-10529490
ABSTRACT
The purpose of this study was to examine the timing and magnitude of cerebral blood flow (CBF) responses to neuronal activation. We measured the changes in local CBF (LCBF), red blood cell (RBC) velocity and RBC concentration by laser-Doppler flowmetry (LDF) as well as field potential recordings during activation of the somatosensory cortex of the rat in response to electrical stimulation of the hind paw. Electrical stimuli, 0.1 ms pulses of 1-1.5 mA for 5 s, were applied at 0.2, 0.5, 5, 10 and 50 Hz under alpha-chloralose anesthesia. LCBF showed the maximum increase at 5 Hz, and rose approximately 0.5 s after the onset of stimulation regardless of the frequency. The maximum frequency of the field potentials was also obtained at 5 Hz. During activation of the somatosensory cortex, the onset of rise in RBC concentration did not precede that of RBC velocity, and the peak RBC concentration was noted earlier than that of both LCBF and RBC velocity, suggesting that both arteriolar diameter and active changes in the capillary contributed to the LCBF response.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
/
Circulação Cerebrovascular
/
Potenciais Somatossensoriais Evocados
Limite:
Animals
Idioma:
En
Revista:
Jpn J Physiol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Japão