Quote from Wikipedia:
Aniracetam (Draganon, Sarpul, Ampamet, Memodrin, Referan), also known as N-anisoyl-2-pyrrolidinone, is an ampakine nootropic of the racetam chemical class purported to be considerably more potent than piracetam. It is lipid-soluble and has possible cognition-enhancing effects. It has been tested in animals extensively, Alzheimer's patients, and temporarily impaired healthy subjects. It has shown potential as an anxiolytic in three clinical animal models. It is sold in Europe as a prescription drug, but it is not approved by the Food and Drug Administration for use in the United States.
Aniracetam has also been shown to positively modulate the AMPA receptor and was used as the parent compound to derive a class of drugs known as theampakines that are being investigated as nootropics and neuroprotective drugs for the treatment of Alzheimer's disease and other neurodegenerative conditions.
After a confirmed test of the anxiolytic efficacy in a mouse model, haloperidol, mecamylamine, and ketanserin were applied to determine the pathways aniracetam depends on to exert its anti-anxiety effects. Haloperidol completely reversed the anxiolytic effects, and mecamylamine and ketanserin nearly completely reversed the effects. This shows that aniracetam's anxiolytic mechanism is possibly mediated through D2, nACh, or 5-HT2A receptor activity.