A novel cortico-intrathalamic circuit for flight behavior

• Published in: Nature neuroscience Vol. 22; no. 6; pp. 941 - 949
• Main Authors: Dong, Ping, Wang, Hao, Shen, Xiao-Fan, Jiang, Ping, Zhu, Xu-Tao, Li, Yue, Gao, Jia-Hao, Lin, Shan, Huang, Yue, He, Xiao-Bin, Xu, Fu-Qiang, Duan, Shumin, Lian, Hong, Chen, Jiadong, Li, Xiao-Ming
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-06-2019; Nature Publishing Group
• Subjects: 13/1; 13/51; 14/19; 38/35; 45/77; 631/378/1457/1601; 631/378/1595/2636; 631/378/3920; 64/60; 9/74; Activation; Alarm reaction; Animal Genetics and Genomics; Animals; Behavior; Behavioral Sciences; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Brain research; Cerebral cortex; Cerebral Cortex - physiology; Circuits; Cortex (cingulate); Cortex (somatosensory); Escape Reaction - physiology; Flight behavior; Freezing; Glutamatergic transmission; Information processing; Inhibition; Laboratories; Male; Mice; Mice, Inbred C57BL; Neural circuitry; Neural Pathways - physiology; Neurobiology; Neurons - physiology; Neurosciences; Noise; Parvalbumin; Physiological aspects; Risk assessment; Thalamic Nuclei - physiology; Thalamic reticular nucleus; Thalamus; Tonic immobility
• ISSN: 1097-6256; 1546-1726
• DOI: 10.1038/s41593-019-0391-6

Flight, an active fear response to imminent threat, is dependent on the rapid risk assessment of sensory information processed by the cortex. The thalamic reticular nucleus (TRN) filters information between the cortex and the thalamus, but whether it participates in the regulation of flight behavior remains largely unknown. Here, we report that activation of parvalbumin-expressing neurons in the limbic TRN, but not those in the sensory TRN, mediates flight. Glutamatergic inputs from the cingulate cortex (Cg) selectively activate the limbic TRN, which in turn inhibits the intermediodorsal thalamic nucleus (IMD). Activation of this Cg→limbic TRN→IMD circuit results in inhibition of the IMD and produces flight behavior. Conversely, removal of inhibition onto the IMD results in more freezing and less flight, suggesting that the IMD may function as a pro-freeze center. Overall, these findings reveal a novel corticothalamic circuit through the TRN that controls the flight response.
Dong, Wang et al. uncover a circuit linking Glu
+
cingulate inputs→PV
+
neurons in the limbic thalamic reticular nucleus→intermediodorsal thalamic nucleus, and show that this cortico-intrathalamic circuit is a component of the fear circuitry and controls flight behavior in mice.