A molecularly defined amygdala-independent tetra-synaptic forebrain-to-hindbrain pathway for odor-driven innate fear and anxiety

• Published in: Nature neuroscience 2024-03, Vol.27 (3), p.514-526
• Main Authors: Wang, Hao, Wang, Qin, Cui, Liuzhe, Feng, Xiaoyang, Dong, Ping, Tan, Liheng, Lin, Lin, Lian, Hong, Cao, Shuxia, Huang, Huiqian, Cao, Peng, Li, Xiao-Ming
• Format: Article
• Language: English
• Subjects: 13/51; 14/19; 38/32; 631/378/2624; 631/378/3920; 631/378/87; 9/74; Amygdala; Animal Genetics and Genomics; Anxiety; Behavioral Sciences; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Cholecystokinin; Fear; Fear & phobias; Forebrain; Hindbrain; Neurobiology; Neurons; Neurosciences; Odor; Odors; Olfaction; Olfactory bulb; Olfactory stimuli; Parabrachial nucleus; Public health; Pyramidal cells; Sensory evaluation; Somatosensory cortex; Substrates; Tachykinin; Tachykinin receptors
• ISSN: 1097-6256; 1546-1726
• DOI: 10.1038/s41593-023-01562-7

Fear-related disorders (for example, phobias and anxiety) cause a substantial public health problem. To date, studies of the neural basis of fear have mostly focused on the amygdala. Here we identify a molecularly defined amygdala-independent tetra-synaptic pathway for olfaction-evoked innate fear and anxiety in male mice. This pathway starts with inputs from the olfactory bulb mitral and tufted cells to pyramidal neurons in the dorsal peduncular cortex that in turn connect to cholecystokinin-expressing ( Cck + ) neurons in the superior part of lateral parabrachial nucleus, which project to tachykinin 1-expressing ( Tac1 + ) neurons in the parasubthalamic nucleus. Notably, the identified pathway is specifically involved in odor-driven innate fear. Selective activation of this pathway induces innate fear, while its inhibition suppresses odor-driven innate fear. In addition, the pathway is both necessary and sufficient for stress-induced anxiety-like behaviors. These findings reveal a forebrain-to-hindbrain neural substrate for sensory-triggered fear and anxiety that bypasses the amygdala. Wang et al. identify a molecularly defined tetra-synaptic pathway for olfaction-evoked innate fear and anxiety in mice. These findings reveal a forebrain-to-hindbrain neural substrate for sensory-triggered fear and anxiety that bypasses the amygdala.