MPP+, sold as the chloride salt under the brand name cyperquat, was used briefly in the 1970s as an herbicide to protect crops against nutsedge, a member of the cyperus genus of plants.[1] MPP+ as a salt has much lower acute toxicity than its precursor MPTP due to the inability of the former to pass through the blood-brain barrier and ultimately access the only cells that will permit its uptake, the dopaminergic neurons.[2] While cyperquat is no longer used as an herbicide, a closely related compound named paraquat is.[3] Given the structural similarities, some[3] have raised concerns about paraquat's active use as an herbicide for those handling it.