The "Anxiety state" and its relation with rat models of memory and habituation

Rats selected as "anxious", "nonanxious," or normal according to their beha vior in an elevated plus maze were submitted to memory tasks and the densit ies of central benzodiazepine receptors in the amygdala and the hippocampus were studied. Anxious rats exibited better retention scores in the inhibit ory avoidance task while nonanxious rats exibited worse retention scores in inhibitory and two-way active avoidance tasks compared to normal rats. No significant differences were detected in the retention scores for habituati on to an open field. Nonanxious rats presented a lower benzadiazepine recep tor density in the hippocampus but not in the amygdala compared to the othe r groups. These data suggest that the benzodiazepine receptors are involved in the effect of "anxiety" or emotional states on memory storage processes . (C) 1999 Academic Press.