This dataset supports the Cell Reports publication entitled 'Optogenetic activation of striatal D1/D2 medium spiny neurons differentially engages downstream connected areas beyond the basal ganglia' (https://doi.org/10.1016/j.celrep.2021.110161). Please refer to this publication for detailed information. The dataset contains functional (GE-BOLD) and anatomical (T1-weighted) scans of a total of 34 subjects (Cre-mouse lines Drd1-Cre, Drd2-Cre, A2A-Cre, and wildtype mice) in NIFTI format, multiplied by 10. The 'StimulationProtocol' text file specifies the precise onset (in seconds) and duration (in seconds) of the optogenetic stimulation during a 480 seconds functional scan. The 'SubjectDetails' file lists the subject IDs, their gender, their genotype, the number of functional scans, and whether they have an associated anatomical scan.