HDAC9 and cocaine dependence: In another study, to explore the effect of selective degradation of HDAC4 and HDAC5 on cocaine addiction–like behaviors, 0.5 mg/kg MC1568 was administered i.p. daily for 10 consecutive days demonstrating 35% decrease in HDACs class IIa activity in the n. accumbens and no inhibition of HDAC class I enzymes69.