Blueprints for measuring natural behavior

Abstract

Until recently laboratory tasks for studying behavior were highly artificial, simplified, and designed without consideration for the environmental or social context. Although such an approach offers good control over behavior, it does not allow for researching either voluntary responses or individual differences. Importantly for neuroscience studies, the activity of the neural circuits involved in producing unnatural, artificial behavior is variable and hard to predict. In addition, different ensembles may be activated depending on the strategy the animal adopts to deal with the spurious problem. Thus, artificial and simplified tasks based on responses, which do not occur spontaneously entail problems with modeling behavioral impairments and underlying brain deficits. To develop valid models of human disorders we need to test spontaneous behaviors consistently engaging well-defined, evolutionarily conserved neuronal circuits. Such research focuses on behavioral patterns relevant for surviving and thriving under varying environmental conditions, which also enable high reproducibility across different testing settings.

Keywords: Behavioral neuroscience; Biological sciences; Neuroscience.

Graphical abstract

Figure 1

Issues arising from testing behavior under rigid laboratory conditions lead to notorious irreproducibility of results obtained in the field of behavioral neuroscience

Figure 2

A contrived environment leads to rigid behaviors (A) Stereotypic behaviors, such as pacing the fence, are often observed in captive wild animals living under conditions far more simplistic than those of their natural habitats. (B) By the means of extensive shaping, it is feasible to teach laboratory animals to perform very elaborate behaviors, which never spontaneously occur in nature. Here a laboratory rat is taught to “play basketball” (see also: https://www.youtube.com/watch?v=drnnulHw5CM).

Figure 3

The behavior of the individuals depends on the environmental and social constraints The diagrams illustrate differing social interactions under varying housing conditions. (A) Mice amicably interact in the enriched, socially-adequate environment. (B) Animals of the same strain present aggressive behaviors and isolate themselves as a result of being subjected to overcrowding and impoverished conditions.

Figure 4

Graphic representation of social networks in humans (A) and mice (B) illustrating varying within-group positions and relations Social network structures in both species are visualized as node-edge graphs. The nodes represent subgroups (A) or individuals (B). (B) The bigger the node, the higher the position within the social structure. The thickness of the edges between the nodes represents the strength of the social connections—the thicker the lines, the more frequent the interactions.