Defensive responses: behaviour, the brain and the body

• Published in: Nature reviews. Neuroscience Vol. 24; no. 11; pp. 655 - 671
• Main Authors: Tseng, Yu-Ting, Schaefke, Bernhard, Wei, Pengfei, Wang, Liping
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.11.2023; Nature Publishing Group
• Subjects: 631/378/1457; 631/378/1959; 631/378/3920; Adaptation, Psychological; Animal Genetics and Genomics; Animals; Behavior; Behavior, Animal; Behavioral Sciences; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Brain; Brain research; Defensive behavior; Foraging behavior; Information processing; Mating; Mating behavior; Neurobiology; Neuroethology; Neurosciences; Predation; Predators; Predatory Behavior; Review Article; Reviews
• ISSN: 1471-003X; 1471-0048; 1469-3178
• DOI: 10.1038/s41583-023-00736-3

Most animals live under constant threat from predators, and predation has been a major selective force in shaping animal behaviour. Nevertheless, defence responses against predatory threats need to be balanced against other adaptive behaviours such as foraging, mating and recovering from infection. This behavioural balance in ethologically relevant contexts requires adequate integration of internal and external signals in a complex interplay between the brain and the body. Despite this complexity, research has often considered defensive behaviour as entirely mediated by the brain processing threat-related information obtained via perception of the external environment. However, accumulating evidence suggests that the endocrine, immune, gastrointestinal and reproductive systems have important roles in modulating behavioural responses to threat. In this Review, we focus on how predatory threat defence responses are shaped by threat imminence and review the circuitry between subcortical brain regions involved in mediating defensive behaviours. Then, we discuss the intersection of peripheral systems involved in internal states related to infection, hunger and mating with the neurocircuits that underlie defence responses against predatory threat. Through this process, we aim to elucidate the interconnections between the brain and body as an integrated network that facilitates appropriate defensive responses to threat and to discuss the implications for future behavioural research. Research has often considered defensive behaviour as entirely mediated by the brain processing threat-related information. In this Review, Tseng et al. elucidate the interconnected network between the brain and body that facilitates defensive responses to threats varying in imminence.