(+)-Naloxone blocks Toll-like receptor 4 to ameliorate deleterious effects of stress on male mouse behaviors

Eva M. Medina-Rodriguez, Kenner C. Rice, Eléonore Beurel, Richard S Jope

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Depression is a leading cause of disability worldwide and current treatments are often inadequate for many patients. Increasing evidence indicates that inflammation contributes to susceptibility to depression. We hypothesized that targeting Toll-like receptor 4 (TLR4), one of the main signaling pathways for triggering an inflammatory response, would lessen stress-induced depression-like behaviors in male mice. TLR4 inhibition with the CNS-penetrating drug (+)-naloxone that is a TLR4 antagonist but is inactive at opiate receptors increased resistance to the learned helplessness model of depression and provided an antidepressant-like effect in the tail suspension test. (+)-Naloxone administration also reversed chronic restraint stress-induced impairments in social behavior and novel object recognition. These effects involved blockade of stress-induced activation of glycogen synthase kinase 3β (GSK3β), NF-κB, IFN regulatory factor 3 (IRF3) and nitric oxide production, and reduced levels of the cytokines tumor necrosis factor-α (TNFα) and interferon-β (IFNβ). These findings demonstrate that blocking TLR4 with (+)-naloxone effectively diminishes several detrimental responses to stress and raise the possibility that (+)-naloxone may be a feasible intervention for depression.

Original languageEnglish (US)
Pages (from-to)226-234
Number of pages9
JournalBrain, Behavior, and Immunity
StatePublished - Nov 2020


  • (+)-naloxone
  • Depression
  • Inflammation
  • Toll-like receptor-4

ASJC Scopus subject areas

  • Immunology
  • Endocrine and Autonomic Systems
  • Behavioral Neuroscience


Dive into the research topics of '(+)-Naloxone blocks Toll-like receptor 4 to ameliorate deleterious effects of stress on male mouse behaviors'. Together they form a unique fingerprint.

Cite this