Sex and estrogen receptor expression influence opioid peptide levels in the mouse hippocampal mossy fiber pathway
| Autor: | Andreina D. Gonzalez, Sonoko Ogawa, Teresa A. Milner, Elizabeth M. Waters, Joanna L. Spencer-Segal, Mumeko C. Tsuda, Tracey A. Van Kempen, Sana Kahlid, Bruce S. McEwen |
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| Rok vydání: | 2013 |
| Předmět: |
Male
Mossy fiber (hippocampus) endocrine system medicine.medical_specialty Enkephalin Estrous Cycle Dynorphin Biology Dynorphins Article Mice chemistry.chemical_compound Internal medicine medicine Animals Estrogen Receptor beta Opioid peptide Estrogen receptor beta Hippocampal mossy fiber Mice Knockout Sex Characteristics Estradiol General Neuroscience Estrogen Receptor alpha Enkephalins CA3 Region Hippocampal Endocrinology chemistry Dentate Gyrus Mossy Fibers Hippocampal Estradiol benzoate Female Estrogen receptor alpha |
| Zdroj: | Neuroscience Letters. 552:66-70 |
| ISSN: | 0304-3940 |
| DOI: | 10.1016/j.neulet.2013.07.048 |
| Popis: | The opioid peptides, dynorphin (DYN) and enkephalin (L-ENK) are contained in the hippocampal mossy fiber pathway where they modulate synaptic plasticity. In rats, the levels of DYN and L-ENK immunoreactivity (-ir) are increased when estrogen levels are elevated (Torres-Reveron et al. 2008 and 2009). Here, we used quantitative immunocytochemistry to examine whether opioid levels are similarly regulated in wildtype (WT) mice over the estrous cycle, and how these compared to males. Moreover, using estrogen receptor (ER) alpha and beta knockout mice (AERKO and BERKO, respectively), the present study examined the role of ERs in rapid, membrane-initiated (6 hr), or slower, nucleus-initiated (48 hr) estradiol effects on mossy fiber opioid levels. Unlike rats, the levels of DYN and L-ENK-ir did not change over the estrous cycle. However, compared to males, females had higher levels of DYN-ir in CA3a and L-ENK-ir in CA3b. In WT and BERKO ovariectomized (OVX) mice, neither DYN- nor L-ENK-ir changed following 6 or 48 hrs estradiol benzoate (EB) administration. However, DYN-ir significantly increased 48 hours after EB in the dentate gyrus (DG) and CA3b of AERKO mice only. These findings suggest that cyclic hormone levels regulate neither DYN nor L-ENK levels in the mouse mossy fiber pathway as they do in the rat. This may be due to species-specific differences in the mossy fiber pathway. However, in the mouse, DYN levels are regulated by exogenous EB in the absence of ERα possibly via an ERβ-mediated pathway requiring new gene transcription. |
| Databáze: | OpenAIRE |
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