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Researchers from the University of Tsukuba have discovered that estrogen receptor (ER) β, expressed in the lateral septum of the limbic system, plays a crucial role in suppressing anxiety-like behavior exhibited by male mice in social situations. They also discovered that the distribution and expression region of ERβ differs from that of ERα.

Tsukuba, Japan—Estradiol (E2), a sex steroid hormone, plays an essential role in social behavior, including regulating social anxiety, which is anxiety experienced when unknown individuals are encountered. In males, testosterone secreted by the testes is converted to E2 in the brain, and the E2 binds to two types of estrogen receptors (ERs), ERα and ERβ, to regulate social behavior. However, its neuroendocrine basis has not been understood. In this study, the role of ERα and ERβ expressed in the lateral septum (LS), which regulates social anxiety, was investigated using male mice.

The researchers first investigated the expression of ERα and ERβ in LS using genetically modified male mice. ERβ-expressing cells in the mice were labeled with red fluorescent protein, which revealed that the distributions of ERα and ERβ are different. Furthermore, the researchers investigated the knockdown effects of ERα or ERβ gene expression in the LS of male mice during situations of social and nonsocial anxiety. The results show that social anxiety increases with the inhibition of ERβ expression. Additionally, ERα- and ERβ-positive cells in the LS projected into different regions of the hypothalamus. Thus, the researchers concluded that ERα- and ERβ-expressing cells in LS are distinct cell populations with different localizations and neuronal projections, and the ERβ population plays a crucial role in neural circuitry that regulates anxiety-like behavior in social situations.

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This work was supported by grant-in-aid for Scientific Research 15H05724, 21K18547, and 22H02941 to SO.

Original Paper

Title of original paper:

Estrogen Receptor β in the Lateral Septum Mediates Estrogen Regulation of Social Anxiety-like Behavior in Male Mice

Journal:

Neuroscience

DOI:

10.1016/j.neuroscience.2023.11.019

Correspondence

Dr. OGAWA Sonoko
Laboratory of Behavioral Neuroendocrinology, Institute of Human Sciences, University of Tsukuba

HASUNUMA Kansuke
Doctoral Program in Neuroscience, Graduate School of Comprehensive Human Sciences, University of Tsukuba

Related Link

Institute of Human Sciences