I utilize a combination of behavioral pharmacology, behavioral neuroscience, and neuroimmunology approaches to examine how neuroimmune signaling within key corticolimbic brain structures, such as the mPFC and NAc, contributes to drug-seeking behavior. Currently, I am examining how HIV dysregulates corticostriatal microglia plasticity to contribute to impaired extinction of cocaine seeking behavior and enhanced relapse vulnerability.

Select Publications

1. *Namba, M.D., Phillips, M.N., Neisewander, J.L., & Olive, M.F. (2022). Nuclear Factor Kappa B Signaling within the Rat Nucleus Accumbens Core Regulates Cue-Induced Cocaine Seeking Sex-Dependently. Brain, Behavior, and Immunity, 102, 252-265. PMID: 35259426. Commentary by Reverte et al., 2022, Brain, Behavior, and Immunity, 104, 29-30. 

2. *Namba, M.D., Leyrer-Jackson, J.M., Nagy, E.K., Olive, M.F., & *Neisewander, J.L. (2021). Neuroimmune Mechanisms as Novel Treatment Targets for Substance Use Disorders and Associated Comorbidities. Frontiers Neuroscience, 15. PMID: 33935636

3. Namba, M.D., Kupchik, Y.M., Spencer, S.M., Garcia-Keller, C., Goenaga, J.G., Powell, G.L., Vicino, I.A., Hogue, I.B., & *Gipson, C.D. (2020). Accumbens neuroimmune signaling and dysregulation of astrocytic glutamate transport underlie conditioned nicotine seeking. Addiction Biology, e12797. PMID: 31330570

Another line of my work is investigating the contributions of corticostriatal astrocytes and microglia to HIV-induced reward learning impairments. Ongoing experiments include examining the impact of chemogenetic manipulation of mPFC astrocytes within the EcoHIV mouse model on extinction learning as well as the impact of EcoHIV infection on the morphology of corticostriatal microglia.

Select Publications

1. Namba, M.D., Xie, Q., Park, K., Jackson, J.G., & *Barker, J.M. (2025). EcoHIV Infection Modulates the Effects of Cocaine Exposure Pattern and Abstinence on Cocaine Seeking and Neuroimmune Signaling in Male Mice. Addiction Neuroscience, 15, 100208. 

2. Namba, M.D., Xie, Q., & *Barker, J.M. (2023). Advancing the Preclinical Study of Comorbid NeuroHIV and Substance Use Disorders: Current Perspectives and Methodological Considerations. Brain, Behavior, & Immunity, 113, 453-475. PMID: 37567486

A line of work that is currently under development is the integration of novel preclinical models of polysubstance use and HIV. Currently, I am examining the impact of HIV and/or cocaine co-exposure on opioid-related behaviors and associated neuroimmune mechanisms. Current preliminary data suggests that a history of cocaine co-exposure can potentiate oxycodone seeking under extinction conditions. Ongoing work will assess how HIV, which disrupts inhibitory learning, can modulate this effect.