CTBP1 and amnesia: However, this post-retrieval amnesia for learned fear only became apparent when (a) the amnesic drug passed the blood–brain barrier, thereby targeting the centrally located β-ARs; (b) the amnesic drug was given within a specific time-window that spanned the time before, during, and after memory reactivation; and (c) the participants were tested 12 or 24 h later and that this delay included a night of sleep.