ArticleBrain research2011
Age- and hormone-regulation of opioid peptides and synaptic proteins in the rat dorsal hippocampal formation.
Article in Brain research, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 19 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
19 citing papers in PubMed, 31 citations in OpenAlex.
- Estradiol Replacement Modulates Synaptic Transmission-Related Proteins in the Hippocampus of Ovariectomized Rats: An Exploratory Proteomic Approach.Journal of neurochemistry · 2026Article
- Beyond Estrogen: Unraveling the Complexities of Hormonal Signaling Pathways in Alzheimer's Disease and Their Implications for Precision Therapy.Molecular neurobiology · 2025Review
- Proteomic analysis of plasma proteins during fentanyl withdrawal in ovariectomized female rats with and without estradiol.Journal of neuroendocrinology · 2025Article
- The role of estrogen in Alzheimer's disease pathogenesis and therapeutic potential in women.Molecular and cellular biochemistry · 2025Review
- Sex differences in the rodent hippocampal opioid system following stress and oxycodone associated learning processes.Pharmacology, biochemistry, and behavior · 2022Review
- Regulation of Opioid Receptors by Their Endogenous Opioid Peptides.Cellular and molecular neurobiology · 2021Article
- From adolescence to late aging: A comprehensive review of social behavior, alcohol, and neuroinflammation across the lifespan.International review of neurobiology · 2019Review
- Ovarian Function Modulates the Effects of Long-Chain Polyunsaturated Fatty Acids on the Mouse Cerebral Cortex.Frontiers in cellular neuroscience · 2018Article
- Female rats are resistant to developing the depressive phenotype induced by maternal separation stress.Metabolic brain disease · 2016Article
- Re-Opening the Critical Window for Estrogen Therapy.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2015Article
- Mouse model of OPRM1 (A118G) polymorphism has altered hippocampal function.Neuropharmacology · 2015Article
- Estrogen Effects on Cognitive and Synaptic Health Over the Lifecourse.Physiological reviews · 2015Review
- Opioid receptor-dependent sex differences in synaptic plasticity in the hippocampal mossy fiber pathway of the adult rat.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2015Article
- Decreased insulin-like growth factor-I and its receptor expression in the hippocampus and somatosensory cortex of the aged mouse.Neurochemical research · 2014Article
- Stress differentially alters mu opioid receptor density and trafficking in parvalbumin-containing interneurons in the female and male rat hippocampus.Synapse (New York, N.Y.) · 2013Article
- Factors influencing the cognitive and neural effects of hormone treatment during aging in a rodent model.Brain research · 2013Review
- Effects of long-term treatment with estrogen and medroxyprogesterone acetate on synapse number in the medial prefrontal cortex of aged female rats.Menopause (New York, N.Y.) · 2012Article
- Effects of estrogen and aging on the synaptic distribution of phosphorylated Akt-immunoreactivity in the CA1 region of the female rat hippocampus.Brain research · 2011Article
- Hormonal regulation of delta opioid receptor immunoreactivity in interneurons and pyramidal cells in the rat hippocampus.Neurobiology of learning and memory · 2011Article
Corrections and comments
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Authors and funding
8 authors at 4 institutions in 1 country.
Funding
Abstract
Circulating estrogen levels and hippocampal-dependent cognitive functions decline with aging. Moreover, the responses of hippocampal synaptic structure to estrogens differ between aged and young rats. We recently reported that estrogens increase levels of post-synaptic proteins, including PSD-95, and opioid peptides leu-enkephalin and dynorphin in the hippocampus of young animals. However, the influence of ovarian hormones on synaptic protein and opioid peptide levels in the aging hippocampus is understudied. Here, young (3- to 5-month-old), middle-aged (9- to 12-month-old), and aged (about 22-month-old) female rats were ovariectomized and then, 4 weeks later, subcutaneously implanted with a silastic capsule containing vehicle or 17β-estradiol. After 48 h, rats were subcutaneously injected with progesterone or vehicle and sacrificed 1 day later. Coronal sections through the dorsal hippocampus were processed for quantitative peroxidase immunohistochemistry of leu-enkephalin, dynorphin, synaptophysin, and PSD-95. With age, females showed opposing changes in leu-enkephalin and dynorphin levels in the mossy fiber pathway, particularly within the hilus, and regionally specific changes in synaptic protein levels. 17β-estradiol, with or without progesterone, altered leu-enkephalin levels in the dentate gyrus and synaptophysin levels in the CA1 of young but not middle-aged or aged females. Additionally, 17β-estradiol decreased synaptophysin levels in the CA3 of middle-aged females. Our results support and extend previous findings indicating 17β-estradiol modulation of hippocampal opioid peptides and synaptic proteins while demonstrating regional and age-specific effects. Moreover, they lend credence to the "window of opportunity" hypothesis during which hormone replacement can modulate hippocampal structure and circuitry to improve cognitive outcomes.
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Registered trials
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