# Corticolimbic circuit and neuroimmune mechanisms of comorbid HIV and cocaine use

> **NIH NIH F32** · DREXEL UNIVERSITY · 2024 · $78,784

## Abstract

Project Summary/Abstract
Cocaine use disorders (CUDs) and human immunodeficiency virus (HIV) are persistent public health concerns
worldwide. Psychostimulants such as cocaine can facilitate viral replication and neuroinvasion into the central
nervous system, which can exacerbate HIV-associated neurocognitive dysfunction that is observed even among
those virally suppressed under antiretroviral therapy (ART). Unlike other addictive substances, cocaine does not
have effective FDA-approved medications for helping individuals reduce their cocaine use or maintain long-term
abstinence. Moreover, it is possible that comorbidities such as HIV may impair the efficacy of medications that
may be otherwise effective at treating CUDs (e.g., Namba et al., 2023, Addiction Neuro.). Taken together,
identifying the unique cellular- and circuit-specific mechanisms underlying drug seeking and relapse-like
behavior in the context of HIV is imperative for developing targeted and effective treatments for vulnerable
subpopulations of individuals, such as PLWH suffering from CUDs. This proposal aims to elucidate corticostriatal
and neuroimmune mechanisms underlying HIV-induced dysregulation of reward seeking, with the ultimate goal
of identifying novel CUD treatment targets for PLWH. My preliminary work has revealed that mice infected with
the chimeric HIV construct, EcoHIV, display potentiated cocaine-seeking behavior, impaired extinction learning,
as well as dysregulated peripheral and corticolimbic neuroimmune function. A wide breadth of studies
demonstrate that activity of neuronal projections from the infralimbic cortex (IL) region of the prefrontal cortex
(PFC) to the nucleus accumbens shell (NAcSh) are necessary for both the acquisition and expression of
extinction learning and facilitate refraining from drug seeking. As well, PFC dysfunction is also heavily implicated
in HIV at both the clinical and preclinical level. In Aim 1 of this proposal, I will use circuit-specific, closed-loop
optogenetics to stimulate the IL→NAcSh circuit to rescue EcoHIV-induced deficits in extinction learning in male
and female mice. Given the putative role of microglia in HIV-associated neuropathology, I will also explore
EcoHIV- and cocaine-induced plasticity of NAcSh microglia in Aim 2. Here, I will employ a combination of
designer receptors exclusively activated by designer drugs (DREADDs) expressed specifically in microglia with
quantitative microglial morphometry to 1) characterize how microglial morphology changes due to cocaine and
EcoHIV infection and 2) determine whether Gi-coupled DREADD stimulation on microglia suppresses EcoHIV-
induced potentiation of cocaine seeking. This research has the potential to reveal novel corticolimbic circuit and
neuroimmune mechanisms underlying HIV-induced dysregulation of reward-seeking behavior, which will
advance our understanding of, and identification of treatment targets for, comorbid HIV and CUDs. Throughout
the proposed training period...

## Key facts

- **NIH application ID:** 10924743
- **Project number:** 1F32DA060768-01
- **Recipient organization:** DREXEL UNIVERSITY
- **Principal Investigator:** Mark D Namba
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $78,784
- **Award type:** 1
- **Project period:** 2024-07-01 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10924743

## Citation

> US National Institutes of Health, RePORTER application 10924743, Corticolimbic circuit and neuroimmune mechanisms of comorbid HIV and cocaine use (1F32DA060768-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10924743. Licensed CC0.

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