Regulation of neural circuit of ejaculation via metabotropic glutamate receptors.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K09420
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56030:Urology-related
• Research Institution: Shiga University of Medical Science
• Principal Investigator: Miwako Masugi-Tokita (馬杉美和子) 滋賀医科大学, 医学部, 客員講師 (10420712)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: mGluR7 / 射精 / 性行動 / シナプス / グルタミン酸受容体

Outline of Final Research Achievements

Metabotropic glutamate receptor subtype 7 (mGluR7) is a member of the group III mGluRs, which localize to presynaptic active zones. We previously reported that mGluR7 knockout (KO) mice exhibit ejaculatory disorders, although they have normal sexual motivation. We hypothesized that mGluR7 regulates ejaculation by potentiating the excitability of the neural circuit in the lumbosacral spinal cord. In the present study, to elucidate the mechanism of impaired ejaculation in mGluR7 KO mice, we eliminated the influence of the brain by spinal transection. Unexpectedly, sexual responses of mGluR7 KO mice were stronger than those of wild-type mice after spinal transection. Histological examination indicated that mGluR7 controls sympathetic neurons as well as parasympathetic neurons. mGluR7 might control ejaculation by multi-level and multi-modal mechanisms. Our study provides insight into the mechanism of ejaculation as well as a strategy for future therapies to treat ejaculatory disorders.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

近年、不妊外来において射精障害の男性が増加している。しかしながら、アモキサピンなどの三環系抗うつ薬が逆行性射精を改善させる例を除き、射精障害に有効な薬物療法はない。
射精のメカニズムは不明な点が多い。mGluR7が射精調節に関与する神経回路を明らかにするために、免疫組織化学的解析を行い、その調節機構について考察した。mGluR7はシナプス前膜の伝達物質放出部位近傍に存在し、グルタミン酸放出の調節をしていると考えられている。今後、早漏や膣内射精障害を含めた遅漏などの射精障害の薬物ターゲットとしてのmGluR7の可能性を探索したい。