Metabolic characterization of the rat motor cortex with fMRS upon chemogenetic excitation

Motivation: To complement previous fMRI studies of interhemispheric pathways, we propose to characterize the interhemispheric metabolism using functional magnetic resonance spectroscopy (1H-fMRS). Goal(s): To demonstrate the feasibility of chemogenetic 1H-fMRS in the rat brain at 7T. Approach: DREADDs and Sham viruses were injected in the right motor cortex of rat. Neural activation was induced by a 1mg/kg IP bolus of Clozapine-N Oxide (CNO). Spectra were acquired continuously prior and following CNO injection and quantified with a temporal resolution of 5 minutes. Results: Relative concentration changes were found for myo-Inositol, Taurine, Glutamate and NAA in the motor cortex of chemo-induced rats following CNO injection. Impact: Functional metabolic findings will greatly complement our knowledge of interhemispheric pathway allowing a better understanding of long-distance circuits known to initiate both excitation and inhibition.