Format

Send to

Choose Destination
J Cereb Blood Flow Metab. 2015 Jun;35(6):922-32. doi: 10.1038/jcbfm.2015.10. Epub 2015 Feb 11.

Neural and hemodynamic responses to optogenetic and sensory stimulation in the rat somatosensory cortex.

Author information

1
Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
2
1] Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA [2] Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
3
1] Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA [2] Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA [3] Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea [4] Departments of Biomedical Engineering and Biological Sciences, Sungkyunkwan University, Suwon, Korea.

Abstract

Introducing optogenetics into neurovascular research can provide novel insights into the cell-specific control of the hemodynamic response. To generalize findings from molecular approaches, it is crucial to determine whether light-activated circuits have the same effect on the vasculature as sensory-activated ones. For that purpose, rats expressing channelrhodopsin (ChR2) specific to excitatory glutamatergic neurons were used to measure neural activity, blood flow, hemoglobin-based optical intrinsic signal, and blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) during optogenetic and sensory stimulation. The magnitude of the evoked hemodynamic responses was monotonically correlated with optogenetic stimulus strength. The BOLD hemodynamic response function was consistent for optogenetic and sensory stimuli. The relationship between electrical activities and hemodynamic responses was comparable for optogenetic and sensory stimuli, and better explained by the local field potential (LFP) than the firing rate. The LFP was well correlated with cerebral blood flow, moderately with cerebral blood volume, and less with deoxyhemoglobin (dHb) level. The presynaptic firing rate had little impact on evoking vascular response. Contribution of the postsynaptic LFP to the blood flow response induced by optogenetic stimulus was further confirmed by the application of glutamate receptor antagonists. Overall, neurovascular coupling during optogenetic control of glutamatergic neurons largely conforms to that of a sensory stimulus.

PMID:
25669905
PMCID:
PMC4640245
DOI:
10.1038/jcbfm.2015.10
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center