The effect of different anesthetics on neurovascular coupling.
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.
Franceschini
Maria Angela
MA
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA. mari@nmr.mgh.harvard.edu
Radhakrishnan
Harsha
H
Thakur
Kiran
K
Wu
Weicheng
W
Ruvinskaya
Svetlana
S
Carp
Stefan
S
Boas
David A
DA
D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001808:Blood Vessels / Q000187:drug effects* / Q000294:innervation*; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004558:Electric Stimulation; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects; D005552:Forelimb / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D006935:Hypercapnia / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D008297:Male; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D013788:Thalamus / Q000187:drug effects / Q000502:physiology
D000777:Anesthetics; D006454:Hemoglobins