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Original Article

Exp Neurobiol 2022; 31(6): 376-389

Published online December 31, 2022

https://doi.org/10.5607/en22024

© The Korean Society for Brain and Neural Sciences

Lateral Septum Somatostatin Neurons are Activated by Diverse Stressors

Myungmo An1,2†, Hyun-Kyung Kim1,2†, Hoyong Park3†, Kyunghoe Kim1,2, Gyuryang Heo1, Han-Eol Park1, ChiHye Chung3* and Sung-Yon Kim1,2*

1Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, 2Department of Chemistry, Seoul National University, Seoul 08826, 3Department of Biological Sciences, Konkuk University, Seoul 05029, Korea

Correspondence to: *To whom correspondence should be addressed.
Sung-Yon Kim, TEL: 82-2-880-4994
e-mail: sungyonkim@snu.ac.kr
ChiHye Chung, TEL: 82-2-450-0432
e-mail: cchung@konkuk.ac.kr
These authors contributed equally to this article.

Received: June 17, 2022; Revised: October 31, 2022; Accepted: December 27, 2022

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

The lateral septum (LS) is a forebrain structure that has been implicated in a wide range of behavioral and physiological responses to stress. However, the specific populations of neurons in the LS that mediate stress responses remain incompletely understood. Here, we show that neurons in the dorsal lateral septum (LSd) that express the somatostatin gene (hereafter, LSdSst neurons) are activated by diverse stressors. Retrograde tracing from LSdSst neurons revealed that these neurons are directly innervated by neurons in the locus coeruleus (LC), the primary source of norepinephrine well-known to mediate diverse stress-related functions in the brain. Consistently, we found that norepinephrine increased excitatory synaptic transmission onto LSdSst neurons, suggesting the functional connectivity between LSdSst neurons and LC noradrenergic neurons. However, optogenetic stimulation of LSdSst neurons did not affect stress-related behaviors or autonomic functions, likely owing to the functional heterogeneity within this population. Together, our findings show that LSdSst neurons are activated by diverse stressors and suggest that norepinephrine released from the LC may modulate the activity of LSdSst neurons under stressful circumstances.

Graphical Abstract


Keywords: Stress, Norepinephrine, Somatostatin, Lateral septum, Locus coeruleus