Ovarian steroids alter mu opioid receptor trafficking in hippocampal parvalbumin GABAergic interneurons
| Autor: | Tanya J. Williams, Annelyn Torres-Reveron, Elizabeth M. Waters, Teresa A. Milner, Carrie T. Drake, Jeannette D. Chapleau, Bruce S. McEwen |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
endocrine system
medicine.medical_specialty Estrous cycle phase Interneuron Enkephalin medicine.drug_class Ovariectomy Receptors Opioid mu Estrous Cycle Hippocampal formation Article Rats Sprague-Dawley Developmental Neuroscience Interneurons Opioid receptor Internal medicine mental disorders medicine Animals Gonadal Steroid Hormones Microscopy Immunoelectron gamma-Aminobutyric Acid Endogenous opioid Estradiol biology Dentate gyrus Cell Membrane Ovary Dendrites Immunohistochemistry Endocytosis Rats Protein Transport Parvalbumins medicine.anatomical_structure Endocrinology Opioid Peptides nervous system Neurology Dentate Gyrus biology.protein Female hormones hormone substitutes and hormone antagonists Parvalbumin |
| Zdroj: | Experimental Neurology. 219:319-327 |
| ISSN: | 0014-4886 |
| DOI: | 10.1016/j.expneurol.2009.06.001 |
| Popis: | The endogenous hippocampal opioid systems are implicated in learning associated with drug use. Recently, we showed that ovarian hormones regulate enkephalin levels in the mossy fiber pathway. This pathway overlaps with parvalbumin (PARV)-basket interneurons that contain the enkephalin-activated mu opioid receptors (MORs) and are important for controlling the “temporal timing” of granule cells. Here, we evaluated the influence of ovarian steroids on the trafficking of MORs in PARV interneurons. Two groups of female rats were analyzed: cycling rats in proestrus (relatively high estrogens) or diestrus; and ovariectomized rats euthanized 6, 24 or 72 h after estradiol benzoate (10 μg, s.c.) administration. Dorsal hippocampal sections were dually immunolabeled for MOR and PARV and examined by light and electron microscopy. As in males, in females MOR-immunoreactivity (-ir) was in numerous PARV-labeled perikarya, dendrites and terminals in the dentate hilar region. Variation in ovarian steroid levels altered the subcellular distribution of MORs in PARV-labeled dendrites but not terminals. In normal cycling rats, MOR-gold particles on the plasma membrane of small PARV-labeled dendrites (area 2 ) had higher density in proestrus rats than in diestrus rats. Likewise, in ovariectomized rats MORs showed higher density on the plasma membrane of small PARV-labeled dendrites 72 h after estradiol exposure. The number of PARV-labeled cells was not affected by estrous cycle phase or estrogen levels. These results demonstrate that estrogen levels positively regulate the availability of MORs on GABAergic interneurons in the dentate gyrus, suggesting cooperative interaction between opioids and estrogens in modulating principal cell excitability. |
| Databáze: | OpenAIRE |
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