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Updated: Apr 30, 2026
Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice
Published on: January 7, 2019
Transcranial Calcium Macro-Imaging From the Auditory Cortex of Thy1-Cre-Driven GCaMP8 Transgenic Rats
Manavu Tohmi1, Hisaaki Namba1, Meiko Kawamura2
1Department of Physiological Sciences, School of Pharmaceutical Sciences, Wakayama Medical University, Wakayama, Japan.
Background:
Genetically encoded calcium indicators such as GCaMP enable us to monitor neuronal activities from living animals at synaptic levels as well as at whole-brain levels. However, the genetic variation of GCaMP transgenic rats is limited compared with the various demands for neuroscience studies on rats.
Method:
We established two transgenic rat lines: one expressing Cre recombinase under the control of the Thy1 promoter and another knock-in line carrying a floxed STOP cassette followed by GCaMP8 inserted into the β-actin locus. We mated these two transgenic rats and produced the Thy1-Cre-driven GCaMP8-expressing rats.
Results:
Approximately 80% of cortical neurons were positive for the GCaMP immunoreactivity. The GCaMP8-expressing rats were subjected to transcranial calcium imaging from the auditory cortex under anesthesia. With this simple procedure, we were able to detect the maximum responses to 68 dB click sounds;ΔF/F0 = 1.2%. The rise time reaching the peak response was approximately 150 ms, and the half decay time was about 150 ms.
Conclusions:
These results suggest that the present GCaMP8-expressing rats as well as their parental transgenic rat strains offer a new tool for cortical macro-imaging and functional mapping with the transcranial approach.
