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Titolo:
Coupling and uncoupling of activity-dependent increases of neuronal activity and blood flow in rat somatosensory cortex
Autore:
Nielsen, AN; Lauritzen, M;
Indirizzi:
Univ Copenhagen, Dept Med Physiol, Copenhagen, Denmark Univ Copenhagen Copenhagen Denmark ept Med Physiol, Copenhagen, Denmark Glostrup Hosp, Dept Clin Neurophysiol, Copenhagen, Denmark Glostrup Hosp Copenhagen Denmark Clin Neurophysiol, Copenhagen, Denmark
Titolo Testata:
JOURNAL OF PHYSIOLOGY-LONDON
fascicolo: 3, volume: 533, anno: 2001,
pagine: 773 - 785
SICI:
0022-3751(20010615)533:3<773:CAUOAI>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
EXCITATORY SYNAPTIC ACTIVITY; LASER-DOPPLER MEASUREMENTS; OXIDE SYNTHASE INHIBITION; NON-NMDA RECEPTORS; NITRIC-OXIDE; BARREL CORTEX; EVOKED-POTENTIALS; CEREBELLAR CORTEX; ELECTRICAL-STIMULATION; WHISKER STIMULATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
54
Recensione:
Indirizzi per estratti:
Indirizzo: Nielsen, AN NeuroSearch, Pederstrupvej 93, DK-2750 Ballerup, Denmark NeuroSearch Pederstrupvej 93 Ballerup Denmark DK-2750 Denmark
Citazione:
A.N. Nielsen e M. Lauritzen, "Coupling and uncoupling of activity-dependent increases of neuronal activity and blood flow in rat somatosensory cortex", J PHYSL LON, 533(3), 2001, pp. 773-785

Abstract

1. Electrical stimulation of the infraorbital nerve was used to examine the coupling between neuronal activity and cerebral blood flow (CBF) in rat somatosensory cortex by laser Doppler flowmetry and extracellular recordingsof field potentials.2. The relationship between field potential (FP) and CBF amplitudes was examined as a function of the stimulus intensity (0-2.0 mA) at fixed frequency (3 Hz). FP amplitudes up to 2.0-2.5 mV were unaccompanied by increases ofCBF. Above this threshold, CBF and FP amplitudes increased proportionally.3. At fixed stimulus intensity of 1.5 mA, CBF increases were highly correlated to PP amplitudes at low frequencies of stimulation (< 2 Hz), but uncoupling was observed at stimulation frequencies of 2-5 Hz. The evoked responses were independent of stimulus duration (8-32 s).4. The first rise in CBF occurred within the first 0.2 s after onset of stimulation in the upper 0-250 <mu>m of the carter. Latencies were longer (1.0-1.2 s) in lower cortical layers in which CBF and FP amplitudes were larger.5. Local AMPA receptor blockade attenuated CBF and FP amplitudes proportionally.6. This study showed that activity-dependent increases in neuronal activity and CBF were linearly coupled under defined conditions, but neuronal activity was well developed before CBF started to increase. Consequently, the absence of a rise in CBF does not exclude the presence of significant neuronal activity. The CBF increase in upper cortical layers preceded the rise inlower layers suggesting that vessels close to or at the brain surface are the first to react to neuronal activity. The activity-dependent rise in CBFwas explained by postsynaptic activity in glutamatergic neurons.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 13/07/20 alle ore 13:04:34