In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

 The dopamine D1 dopamine receptor antagonist SCH 23390 dose dependently ( 7 . 5 - 30 micrograms / kg s . c . ) antagonized the stimulant locomotor effect on both drugs but did not prevent their antiimmobility effect on the behavioral despair test .
dopamine receptor

 7 - Nitroindazole ( 7NI ) , a relatively selective neuronal nitric oxide synthase ( nNOS ) inhibitor . was intraperitoneally administered to the guinea pigs 30 minutes before the onset of local anoxia .
nitric oxide synthase

 Thus , the mutants are deficient in production of the O - antigen polymerase and were termed rfc mutants .

rfc mutants