Microglia are central to neuroimmune responses and undergo dynamic structural and functional changes in models of stress and addiction, and in response to pharmacological treatments. While transcriptomic and proteomic assays provide insights into molecular profiles, morphological analysis remains a valuable proxy for assessing region-specific microglial response. However, morphological features alone often fail to capture the full complexity of microglial function, underscoring the need for standardized methods and complementary approaches. Here, we describe a standardized imaging pipeline for analyzing microglia in the nucleus accumbens core (NAcore), integrating unbiased confocal image acquisition with precise anatomical reference points. We compare two widely used image analysis platforms—IMARIS and CellSelect-3DMorph—highlighting their workflows, output metrics, and utility in quantifying microglial morphology following treatment with adenosine triphosphate (ATP). Both tools detect well described features of microglial dynamics, though they differ in automation level, analysis speed, and output types. Our findings demonstrate that both platforms provide reliable morphological data, with CellSelect-3DMorph offering a rapid, open-access alternative for high-throughput analysis. Additionally, using software-derived parameters in principal component analysis clustering has proven useful for identifying distinct subpopulations of microglia separated by their morphology. This work provides a practical framework for morphological analysis and promotes reproducibility in microglial studies under environmental and pharmacological interventions.

Exposure to chronic stress creates vulnerability to drug misuse and presents a barrier to sustained recovery for many individuals experiencing substance use disorders (SUDs). Preclinical literature demonstrates that stress modulates psychostimulant intake and seeking, yet there are wide gaps in our understanding of the specific mechanisms by which stress promotes brain changes that may govern addiction-related behaviors. Recent data suggest that microglia, innate immune cells in the central nervous system, are highly responsive to chronic stressors, and several mechanistic links have been explored highlighting the critical role microglia play in stress-related brain adaptation. Importantly, psychostimulants may engage similar microglial machinery, which opens the door for investigation into how microglia may be involved in shaping motivation for psychostimulants, especially in the context of stress exposure. The aims of this review are threefold: 1. Offer a brief overview of microglial biology in the adult brain. 2. Review current methods of interrogating microglial function with a focus on morphometric analyses. 3. Highlight preclinical research describing how microglia contribute to brain changes following chronic stress and/or psychostimulant exposure. Ultimately, this review serves to prime investigators studying the intersection of stress and SUDs to consider the relevant impacts of microglial actions.

Exposure to chronic stressors creates vulnerability to drug misuse and a barrier to sustained recovery for many individuals experiencing substance use disorders (SUDs). Preclinical literature demonstrates that stress modulates psychostimulant intake and seeking, yet there are wide gaps in our understanding of the specific mechanisms by which stress promotes brain changes that may govern addiction-related behaviors. Recent data suggest that microglia, innate immune cells in the central nervous system, are highly responsive to chronic stressors, and several mechanistic links have been explored highlighting the critical role microglia play in stress-related brain adaptation. Importantly, psychostimulants may engage similar microglial machinery, which opens the door for investigation into how microglia may be involved in shaping motivation for psychostimulants, especially in the context of stress exposure. The aims of this review are threefold: 1. Offer a brief overview of microglial biology in the adult brain; 2. Review current methods of interrogating microglial function with a focus on morphometric analyses; 3. Highlight preclinical research describing how microglia contribute to brain changes following chronic stress and/or psychostimulant exposure. Ultimately, this review serves to prime investigators studying the intersection of stress and SUDs to consider the relevant impacts of microglial actions.

The United States is currently facing a drug overdose epidemic. The nucleus accumbens core (NAcore), a brain region critical for reward and aversion behaviors, undergoes structural and functional synaptic adaptations in response to chronic drug exposure. However, the molecular mechanisms underlying these adaptations remain poorly understood. In this study, we investigate the role of dual-specificity phosphatase 5 (DUSP5), a phosphatase known to deactivate extracellular signal-regulated kinase (ERK), in cocaine-induced neuroplasticity. While prior research has linked other DUSP family members to various drugs of abuse, the specific role of DUSP5 in cocaine addiction remains unexplored. We hypothesized that lack of DUSP5 contributes to cocaine-induced maladaptive synaptic plasticity in NAcore. To test this, we employed a rat cocaine self-administration model and molecular analyses and mined publicly available single-cell RNA sequencing data from cocaine-treated NAcore. Our findings reveal a role for DUSP5 in cocaine-related synaptic and behavioral adaptations, highlighting DUSP5 and DUSP5-associated signaling pathways as potential mechanisms underlying substance use disorders and as candidates for therapeutic intervention.

Microglia are central to neuroimmune responses and undergo dynamic structural and functional changes in models of stress and addiction, and in response to pharmacological treatments. While transcriptomic and proteomic assays provide insights into molecular profiles, morphological analysis remains a valuable proxy for assessing region-specific microglial response. However, morphological features alone often fail to capture the full complexity of microglial function, underscoring the need for standardized methods and complementary approaches. Here, we describe a standardized imaging pipeline for ana-lyzing microglia in the nucleus accumbens core (NAcore), integrating unbiased confocal image acquisition with precise anatomical reference points. We compare two widely used image analysis platforms—IMARIS and CellSelect-3DMorph—highlighting their work-flows, output metrics, and utility in quantifying microglial morphology following treat-ment with adenosine triphosphate (ATP). Both tools detect well described features of mi-croglial dynamics, though they differ in automation level, analysis speed, and output types. Our findings demonstrate that both platforms provide reliable morphological data, with CellSelect-3DMorph offering a rapid, open-access alternative for high-throughput analysis. Additionally, using software-derived parameters in principal component analy-sis clustering has proven useful for identifying distinct subpopulations of microglia sepa-rated by their morphology. This work provides a practical framework for morphological analysis and promotes reproducibility in microglial studies under environmental and pharmacological interventions.