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Updated: Feb 27, 2026
Simultaneous fMRI and Electrophysiology in the Rodent Brain
Published on: August 19, 2010
Simultaneous GCaMP6-based fiber photometry and fMRI in rats
Zhifeng Liang1, Yuncong Ma2, Glenn D R Watson3
1Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States; The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, 16802, United States; Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031 China.
Background:
Understanding the relationship between neural and vascular signals is essential for interpretation of functional MRI (fMRI) results with respect to underlying neuronal activity. Simultaneously measuring neural activity using electrophysiology with fMRI has been highly valuable in elucidating the neural basis of the blood oxygenation-level dependent (BOLD) signal. However, this approach is also technically challenging due to the electromagnetic interference that is observed in electrophysiological recordings during MRI scanning.
New Method:
Recording optical correlates of neural activity, such as calcium signals, avoids this issue, and has opened a new avenue to simultaneously acquire neural and BOLD signals.
Results:
The present study is the first to demonstrate the feasibility of simultaneously and repeatedly acquiring calcium and BOLD signals in animals using a genetically encoded calcium indicator, GCaMP6. This approach was validated with a visual stimulation experiment, during which robust increases of both calcium and BOLD signals in the superior colliculus were observed. In addition, repeated measurement in the same animal demonstrated reproducible calcium and BOLD responses to the same stimuli.
Comparison With Existing Method(S):
Taken together, simultaneous GCaMP6-based fiber photometry and fMRI recording presents a novel, artifact-free approach to simultaneously measuring neural and fMRI signals. Furthermore, given the cell-type specificity of GCaMP6, this approach has the potential to mechanistically dissect the contributions of individual neuron populations to BOLD signal, and ultimately reveal its underlying neural mechanisms.
Conclusions:
The current study established the method for simultaneous GCaMP6-based fiber photometry and fMRI in rats.
