The effect of different anesthetics on neurovascular coupling

Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA.
NeuroImage (Impact Factor: 6.36). 03/2010; 51(4):1367-77. DOI: 10.1016/j.neuroimage.2010.03.060
Source: PubMed

ABSTRACT

To date, the majority of neurovascular coupling studies focused on the thalamic afferents' activity in layer IV and the corresponding large spiking activity as responsible for functional hyperemia. This paper highlights the role of the secondary and late cortico-cortical transmission in neurovascular coupling. Simultaneous scalp electroencephalography (EEG) and diffuse optical imaging (DOI) measurements were obtained during multiple conditions of event-related electrical forepaw stimulation in 33 male Sprague-Dawley rats divided into 6 groups depending on the maintaining anesthetic - alpha-chloralose, pentobarbital, ketamine-xylazine, fentanyl-droperidol, isoflurane, or propofol. The somatosensory evoked potentials (SEP) were decomposed into four components and the question of which best predicts the hemodynamic responses was investigated. Results of the linear regression analysis show that the hemodynamic response is best correlated with the secondary and late cortico-cortical transmissions and not with the initial thalamic input activity in layer IV. Baseline cerebral blood flow (CBF) interacts with neural activity and influences the evoked hemodynamic responses. Finally, neurovascular coupling appears to be the same across all anesthetics used.

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    • "Electrical excitation results not only in sensory but also in proprioceptive input due to feeble muscle and joint movements. On the other hand, if we consider that the ESI activity correlates with the fMRI, then a small shift of the former toward M1 is possible, especially around 25ms and 65ms, as previous studies suggest (Franceschini et al., 2010Franceschini et al., , 2008). These reveal that the components of the SEPs that most correlate with diffuse optical imaging (DOI) of hemodynamic responses are N1 and P2, rather than P1. "
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    • "iction by neural metabolites , such as Co 2 , K + , and NO . For example , arterial diameters are sensitive to the regulation of smooth muscle membrane potential through activation or inhibition of K + channel activity ( Nelson et al . , 1990 ; Nelson and Quayle , 1995 ) . Different anesthetics can affect neurovascular coupling in different ways ( Franceschini et al . , 2010 ) and also affect functional connectivity measured with rs - fMRI ( Williams et al . , 2010 ; Pan et al . , 2013 ; Grandjean et al . , 2014 ) . Many of the earliest fMRI and rs - fMRI studies used α - chloralose , a typical GABAergic anesthetic popular for functional imaging studies because of its relatively minor influence on neurovasc"

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