In response to experimental results concerning
问题详情
In response to experimental results concerning IBMX, Snyder et al contended that it is not uncommon for psychoactive drugs to have______
A．mixed effects in the brain
B．inhibitory effects on enzymes in the brain
C．close structural relationships with caffeine
D．depressive effects on mouse locomotion
E．the ability to dislodge caffeine from receptors in the brain请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：A
解析：Aisthebestanswer.TheeffectsofIBMXarediscussedinthelastparagraphofthepassage.IBMXapparentlybindstoadenosine-specificreceptorsonneuronalmembranes,but,incontrasttotheothercaffeinederivativesthatSnyderetalexperimentedwith,IBMXdepressesratherthanstimulatesmouselocomotion.SnyderetalrespondtothisexperimentalresultbystatingthatIBMXhas“mixedeffectsinthebrain,anotunusualoccurrencewithpsychoactivedrugs”(line104-107)
