fMRI response to blue light delivery in the naïve brain: implications for combined optogenetic fMRI studies.
Neuroimage
; 66: 634-41, 2013 Feb 01.
Article
in En
| MEDLINE
| ID: mdl-23128081
ABSTRACT
The combination of optogenetics and functional magnetic resonance imaging (fMRI) is referred to as opto-fMRI. Optogenetics utilises genetic engineering to introduce light sensitive actuator proteins into cells. Functional MRI (fMRI) is a specialist form of magnetic resonance imaging concerned with imaging changes in blood flow and oxygenation, linked to regional variation in metabolic activity, in the brain. This study describes a methodological concern regarding the effects of light delivery into the brain for the purposes of opto-fMRI. We show that blue light delivery to the naïve rat brain causes profound fMRI responses, despite the absence of optogenetic activation. We demonstrate that these fMRI responses are dependent upon laser power and show that the laser causes significant heating. We identify how heating impacts upon the MR signal causing NMR frequency shifts, and T1 and T2* changes. This study brings attention to a possible confounder which must be taken into account when opto-fMRI experiments are designed.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain
/
Brain Mapping
/
Magnetic Resonance Imaging
/
Optogenetics
Limits:
Animals
Language:
En
Journal:
Neuroimage
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2013
Type:
Article
Affiliation country:
United kingdom