When the researchers silenced the NMB-neurons, both basal sighing and stress-induced sighing drastically decreased in the mice. When they silenced only the HCRT-neurons, however, only the stress-induced sighing decreased while basal sighing was unaffected.
The researchers found that HCRT-neurons also were responsible for an increased breathing rate when the mice were under confinement stress. Since NMB-neurons only control sighing, and not regular breathing, this finding indicates that the HCRT-neurons are sending signals to other parts of the brain simultaneously to activate different stress-induced behaviors.
“So we’ve found the circuit that regulates all types of sighing, but activates sighs for different reasons using input signals from different parts of the brain. And we found another group of neurons that induces sighing in response to this claustrophobic stress, but also regulates other claustrophobia-related outputs,” said Li, who is also an assistant professor at the U-M School of Dentistry and Medical School.
“These findings give us clues about how the brain is wired to control various behavioral and physiological responses to emotions.”
Funding: The research was supported by the Howard Hughes Medical Institute, U-M, the Walter V. and Idun Berry Foundation and the Francis Family Foundation. In addition to Li, study authors were Xuenan Wang and Chrystian Phillips of U-M and Shi-Bin Li, Lindsay Schwarz, Liqun Luo, Luis de Lecea and Mark Krasnow of Stanford University and Howard Hughes Medical Institute.
The work performed for this study was approved by the U-M Institutional Animal Care & Use Committee and the Stanford University Administrative Panel on Laboratory Animal Care.
University of Michigan
Emily Kagey – University of Michigan
The image is in the public domain.
Original Research: Open access
“Brain circuit of claustrophobia-like behavior in mice identified by upstream tracing of sighing”. by Peng Li, Shi-Bin Li, Xuenan Wang, Chrystian D. Phillips, Lindsay A. Schwarz, Liqun Luo, Luis de Lecea, Mark A. Krasnow.
Cell Reports doi:10.1016/j.celrep.2020.107779