Sex and chronic stress alter delta opioid receptor distribution within rat hippocampal CA1 pyramidal cells following behavioral challenges.

TitleSex and chronic stress alter delta opioid receptor distribution within rat hippocampal CA1 pyramidal cells following behavioral challenges.
Publication TypeJournal Article
Year of Publication2020
AuthorsRubin BR, Johnson MA, Berman JM, Goldstein E, Pertsovskaya V, Zhou Y, Contoreggi NH, Dyer AG, Gray JD, Waters EM, McEwen BS, Kreek MJeanne, Milner TA
JournalNeurobiol Stress
Volume13
Pagination100236
Date Published2020 Nov
ISSN2352-2895
Abstract

Following oxycodone (Oxy) conditioned place preference (CPP), delta opioid receptors (DORs) differentially redistribute in hippocampal CA3 pyramidal cells in female and male rats in a manner that would promote plasticity and opioid-associative learning processes. However, following chronic immobilization stress (CIS), males do not acquire Oxy-CPP and the trafficking of DORs in CA3 pyramidal neurons is attenuated. Here, we examined the subcellular distribution of DORs in CA1 pyramidal cells using electron microscopy in these same cohorts.

CPP: Saline (Sal)-females compared to Sal-males have more cytoplasmic and total DORs in dendrites and more DOR-labeled spines. Following Oxy-CPP, DORs redistribute from near-plasmalemma pools in dendrites to spines in males.

CIS: Control females compared to control males have more near-plasmalemmal dendritic DORs. Following CIS, dendritic DORs are elevated in the cytoplasm in females and near-plasmalemma in males.

CIS plus CPP: CIS Sal-females compared to CIS Sal-males have more DORs on the plasmalemma of dendrites and in spines. After Oxy, the distribution of DORs does not change in either females or males.

Conclusion: Following Oxy-CPP, DORs within CA1 pyramidal cells remain positioned in naïve female rats to enhance sensitivity to DOR agonists and traffic to dendritic spines in naïve males where they can promote plasticity processes. Following CIS plus behavioral enrichment, DORs are redistributed within CA1 pyramidal cells in females in a manner that could enhance sensitivity to DOR agonists. Conversely, CIS plus behavioral enrichment does not alter DORs in CA1 pyramidal cells in males, which may contribute to their diminished capacity to acquire Oxy-CPP.

DOI10.1016/j.ynstr.2020.100236
Alternate JournalNeurobiol Stress
PubMed ID33344692
PubMed Central IDPMC7739044
Grant ListR01 HL136520 / HL / NHLBI NIH HHS / United States
F32 MH102065 / MH / NIMH NIH HHS / United States
R37 MH041256 / MH / NIMH NIH HHS / United States
R01 DA008259 / DA / NIDA NIH HHS / United States
R01 HL098351 / HL / NHLBI NIH HHS / United States
R01 MH041256 / MH / NIMH NIH HHS / United States