Scopolamine interacts with reactions to cat and genotypic emotional reactivity in rat.

In the presence or absence of a cat the effects of scopolamine hydrobromide were investigated on approach, freezing and defecation behaviors of the bidirectionally selectively bred rat strains for emotional reactivity. Compared to the baseline behavior (absence of cat and scopolamine), both the genetic lines showed decrease in approach and increase in freezing in the presence of cat. Scopolamine in the absence of cat did not affect any of the behaviors of the nonreactive strain but increased approach and decreased freezing in the reactive strain. The presence of both cat and scopolamine affected both the strains but differently, i.e., showing no significantly change in the nonreactive, but increase in freezing and decrease in approach in the reactive strain, as compared to the respective baselines.