Defense against environmental threats is essential for animal survival. However, the neural circuits responsible for transforming unconditioned sensory stimuli and generating defensive behaviours remain largely unclear. Here, we show that corticofugal neurons in the auditory cortex (ACx) targeting the inferior colliculus (IC) mediate an innate, sound-induced flight behaviour. Optogenetic activation of these neurons, or their projection terminals in the IC, is sufficient for initiating flight responses, while the inhibition of these projections reduces sound-induced flight responses. Corticocollicular axons monosynaptically innervate neurons in the cortex of the IC (ICx), and optogenetic activation of the projections from the ICx to the dorsal periaqueductal gray is sufficient for provoking flight behaviours. Our results suggest that ACx can both amplify innate acoustic-motor responses and directly drive flight behaviours in the absence of sound input through corticocollicular projections to ICx. Such corticofugal control may be a general feature of innate defense circuits across sensory modalities.
Bibliographical noteFunding Information:
This work was supported by grants to L.I.Z. from the US National Institutes of Health (R01DC008983) and the David and Lucile Packard Foundation (Packard Fellowships for Science and Engineering). H.W.T. was supported by the US National Institutes of Health grant R01EY019049. F.L. was also supported by a grant from The National Natural Science Foundation of China (31200831). We thank Xiaolin Chou for his assistance in the experiments.
© 2015 Macmillan Publishers Limited.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)