Origins of blood volume change due to glutamatergic synaptic activity at astrocytes abutting on arteriolar smooth muscle cells.
J Theor Biol
; 250(1): 172-85, 2008 Jan 07.
Article
em En
| MEDLINE
| ID: mdl-17920632
ABSTRACT
The cellular mechanisms that couple activity of glutamatergic synapses with changes in blood flow, measured by a variety of techniques including the BOLD signal, have not previously been modelled. Here we provide such a model, that successfully accounts for the main observed changes in blood flow in both visual cortex and somatosensory cortex following their stimulation by high-contrast drifting grating or by single whisker stimulation, respectively. Coupling from glutamatergic synapses to smooth muscle cells of arterioles is effected by astrocytes releasing epoxyeicosatrienoic acids (EETs) onto them, following glutamate stimulation of the astrocyte. Coupling of EETs to the smooth muscle of arterioles is by means of potassium channels in their membranes, leading to hyperpolarization, relaxation and hence an increase in blood flow. This model predicts a linear increase in blood flow with increasing numbers of activated astrocytes, but a non-linear increase with increasing glutamate release.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sinapses
/
Volume Sanguíneo
/
Astrócitos
/
Modelos Cardiovasculares
/
Músculo Liso Vascular
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Theor Biol
Ano de publicação:
2008
Tipo de documento:
Article