Effects of the beta-blocker propranolol on cued and contextual fear conditioning in humans.

Rationale: Beta-adrenergic receptors are involved in the consolidation of emotional memories. Yet, a number of studies using Pavlovian cued fear conditioning have been unable to demonstrate an effect of beta-adrenergic blockade on acquisition or retention of fear conditioning. Evidence for the involvement of beta-adrenergic receptors in emotional memories comes mostly from studies using fear inhibitory avoidance in rodents.

Anxiolytic effects of a novel group II metabotropic glutamate receptor agonist (LY354740) in the fear-potentiated startle paradigm in humans.

Rationale: LY354740, a structural analogue of glutamate that shows specificity at the mGluR2/3 receptor, has anxiolytic effects in animal models.

Objective: This study investigated the anxiolytic effects of LY354740 in humans using the fear-potentiated startle reflex methodology.

Methods: Subjects were given either placebo (n=16), 20 mg LY354740 (n=15), or 200 mg LY354740 (n=13).