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Published on: September 23, 2015
Extra-nuclear estrogen receptor GPR30 regulates serotonin function in rat hypothalamus
1Department of Pharmacology and Experimental Therapeutics, Loyola University Chicago School of Medicine, Maywood, IL 60153, USA.
Neuroscience
|December 20, 2008
Summary
Selective serotonin reuptake inhibitors (SSRIs) take weeks to treat mood disorders. Estradiol may accelerate SSRI effects by targeting the GPR30 receptor in the hypothalamus, potentially speeding mood disorder treatment.
Area of Science:
- Neuroendocrinology
- Pharmacology
- Molecular Psychiatry
Background:
- Selective serotonin reuptake inhibitors (SSRIs) are standard treatments for mood disorders, but their therapeutic effects manifest after 1–2 weeks.
- SSRIs function by attenuating serotonin 1A (5-HT(1A)) receptor signaling, leading to reduced oxytocin and adrenocorticotropin hormone (ACTH) release.
- Estradiol also attenuates 5-HT(1A) receptor signaling, but its effects occur more rapidly (within 2 days in rats).
Purpose of the Study:
- To investigate the role of the G-protein-coupled estrogen receptor, GPR30, in the hypothalamus.
- To determine if GPR30 mediates estradiol's rapid attenuation of 5-HT(1A) receptor signaling.
- To explore the potential of targeting GPR30 to accelerate SSRI therapeutic effects in mood disorders.
Main Methods:
- Localization of GPR30 in the hypothalamic paraventricular nucleus (PVN) of rats using immunohistochemistry.
- Assessment of co-localization of GPR30 with 5-HT(1A) receptors, corticotrophin-releasing factor (CRF), and oxytocin.
- Experimental manipulation using pertussis-toxin (PTX) and selective GPR30 agonist (G-1) to evaluate effects on oxytocin and ACTH responses to a 5-HT(1A) receptor agonist.
Main Results:
- High levels of GPR30 were found in the rat PVN, co-localizing with 5-HT(1A) receptors and key neuroendocrine hormones.
- PTX pretreatment blocked estradiol's attenuation of the oxytocin response to 5-HT(1A) receptor stimulation.
- Treatment with the GPR30 agonist G-1 significantly attenuated oxytocin (29%) and ACTH (31%) responses to 5-HT(1A) receptor agonist stimulation.
Conclusions:
- The study identifies GPR30 as a putative extranuclear estrogen receptor involved in estradiol-mediated attenuation of 5-HT(1A) receptor signaling in the PVN.
- GPR30 activation can rapidly attenuate 5-HT(1A) receptor signaling, suggesting a mechanism for accelerating SSRI effects.
- Targeting GPR30 may offer a novel strategy to expedite the therapeutic benefits of SSRIs for mood disorders.
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