Formation of the Looming-evoked Innate Defensive Response during Postnatal Development in Mice

 Shanping Chen1,3 • Huiying Tan1,3 • Zhijie Wang1 • Yu-ting Tseng1 • Xiaotao Li1,2 • Liping Wang1
1 Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-ShenzhenFundamental Research Institutions, Shenzhen 518055, China 
2 Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 
3 University of Chinese Academy of Sciences, Beijing 100049, China
Environmental threats often trigger innate defensive responses in mammals. However, the gradual development of functional properties of these responses during the postnatal development stage remains unclear. Here, we report that looming stimulation in mice evoked flight behavior commencing at P14–16 and had fully developed by P20–24. The visual-evoked innate defensive response was not significantly altered by sensory deprivation at an early postnatal stage. Furthermore, the percentages of wide-field and horizontal cells in the superior colliculus were notably elevated at P20–24. Our findings define a developmental time window for the formation of the visual innate defense response during the early postnatal period and provide important insight into the underlying mechanism.
Innate defensive response; Postnatal stage;Superior colliculus