Bringing natural behaviors into the laboratory: a tribute to Paul MacLean.

Paul MacLean's work has exemplified and encouraged an approach in which natural behaviors are elicited and investigated in laboratory settings. Our own experiences with bringing natural behaviors into the laboratory indicate that this is best achieved by providing the social and environmental stimuli necessary to support these behaviors and by an initial process of ethological/observational analysis of them. Examples discussed in support of these suggestions include the development of more natural habitats, including visible burrow systems (VBS), for fossorial rodents such as rats and mice; analysis of aggressive and defensive behaviors among social groups in such habitats and to introduced predators; and the development of defense test batteries in which individual defensive behaviors may be elicited through manipulations of threat and environmental stimuli. These situations have proved useful in analysis of the effects of drugs active against anxiety-related psychopathologies. However, an equally important use for them is in the analysis of normal defensive and aggressive behaviors. Detailed analysis of natural behaviors in socially and environmentally adequate situations provides an important link between molecular findings and both normal and pathological behavior patterns. Investigation of natural behaviors in adequate stimulus contexts does not represent an antiexperimental stance but one that supplements and enhances the generalizability of more conventional experimental laboratory approaches.