DISSOCIATION OF BENZODIAZEPINE-INDUCED AMNESIA FROM SEDATION BY FLUMAZENIL PRETREATMENT

AThe human amnestic syndrome associated with lesions of the hippocampu s and amygdala is characterized by a selective impairment of recent (e xplicit, episodic) memory. Benzodiazepine (BZ) treated normal subjects demonstrate similar, marked impairments in episodic memory, but in ad dition, BZ also induces sedation and inattention. Thus, the amnestic e ffects of BZ may be secondary to drug-induced sedation. However, when subjects were pretreated with the specific BZ receptor antagonist, flu mazenil, the sedative and attentional effects of diazepam were blocked , but a marked impairment in episodic memory still occurred. This demo nstrates that, using neuropharmacological, methods, it is possible to produce a dissociation of memory impairment from inattention and sedat ion. Such distinct patterns of cognitive dysfunction may serve as mode ls for clinical cognitive syndromes.