The Selective RhoA Inhibitor Rhosin Promotes Stress Resiliency Through Enhancing D1-Medium Spiny Neuron Plasticity and Reducing Hyperexcitability

T. Chase Francis, Alison Gaynor, Ramesh Chandra, Megan E. Fox, Mary Kay Lobo

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Background: Nucleus accumbens dopamine 1 receptor medium spiny neurons (D1-MSNs) play a critical role in the development of depression-like behavior in mice. Social defeat stress causes dendritic morphological changes on this MSN subtype through expression and activation of early growth response 3 (EGR3) and the Rho guanosine triphosphatase RhoA. However, it is unknown how RhoA inhibition affects electrophysiological properties underlying stress-induced susceptibility. Methods: A novel RhoA-specific inhibitor, Rhosin, was used to inhibit RhoA activity following chronic social defeat stress. Whole-cell electrophysiological recordings of D1-MSNs were performed to assess synaptic and intrinsic consequences of Rhosin treatment on stressed mice. Additionally, recorded cells were filled and analyzed for their morphological properties. Results: We found that RhoA inhibition prevents both D1-MSN hyperexcitability and reduced excitatory input to D1-MSNs caused by social defeat stress. Nucleus accumbens–specific RhoA inhibition is capable of blocking susceptibility caused by D1-MSN EGR3 expression. Lastly, we found that Rhosin enhances spine density, which correlates with D1-MSN excitability, without affecting overall dendritic branching. Conclusions: These findings demonstrate that pharmacological inhibition of RhoA during stress drives an enhancement of total spine number in a subset of nucleus accumbens neurons that prevents stress-related electrophysiological deficits and promotes stress resiliency.

Original languageEnglish (US)
Pages (from-to)1001-1010
Number of pages10
JournalBiological Psychiatry
Issue number12
StatePublished - Jun 15 2019

All Science Journal Classification (ASJC) codes

  • Biological Psychiatry

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