SNc DA neurons mainly project to the striatum to regulate motor activity.[4, 5, 6] We conducted the cylinder turning test to study the motor impairment after knocking out SN oxytocin receptors and observed that mice with unilateral Cre virus injection displayed more contralateral circling and the degree of motor impairment increased with the time elapsed following Cre virus infection (Figure S4B, Supporting Information). This evidence concerns the gene OXTR and viral infectious disease.