fMRI detects bilateral brain network activation following unilateral chemogenetic activation of direct striatal projection neurons.

Abnormal structural and functional connectivity in the striatum during neurological disorders has been reported using functional magnetic resonance imaging (fMRI), although the effects of cell-type specific neuronal stimulation on fMRI and related behavioral alterations are not well understood. In this study, we combined DREADD technology with fMRI ("chemo-fMRI") to investigate alterations of spontaneous neuronal activity. These were induced by the unilateral activation of dopamine D1 receptor-expressing neurons (D1-neurons) in the mouse dorsal striatum (DS). After clozapine (CLZ) stimulation of the excitatory DREADD expressed in D1-neurons, the fractional amplitude of low frequency fluctuations (fALFF) increased bilaterally in the medial thalamus, nucleus accumbens and cortex. In addition, we found that the gamma-band of local field potentials was increased in the stimulated DS and cortex bilaterally. These results provide insights for better interpretation of cell type-specific activity changes in fMRI.