Effects of scopolamine on antipredator defense reactions in wild and laboratory rats

摘要: Abstract Two experiments were designed to investigate the effects of scopolamine hydrobromide (0.25–1.0 mg/kg), and its methyl derivative, on defensive reactions rats nonpainful threat stimuli. In first experiment, over dose range studied neither compound significantly altered avoidance, freezing, or attack in wild Rattus rattus confronted by experimenter other predator-related Scopolamine did, however, produce a dose-dependent increase flight distance; this effect was not seen with compound, confirming central cholinergic mediation. second no either behaviour Long-Evans prior cat exposure. During exposure, (but scopolamine) increased amount time spent vicinity cat, scanning rearing, reduced grooming behaviour. Although reliable, latter pronounced. Together, these data do support major involvement muscarinic receptor mechanisms regulation patterns laboratory rats.