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Lucerne, K. E.

Publications and source records attributed to Lucerne, K. E..

4 recordsLinked to original sources

Granulocyte colony-stimulating factor acts through calcium-permeable AMPA receptors to potentiate cocaine reward

Neuroimmune interactions have emerged as critical modulators of substance use disorders and may represent promising translational therapeutic targets. In prior work, we demonstrated that the cytokine granulocyte colony stimulating factor (G-CSF) is elevated in mice following cocaine exposure, with circulating levels correlating with cocaine intake and locomotor sensitization. Additionally, exogenous G-CSF enhances cocaine reward and increases low-dose cocaine self-administration. We have further shown that repeated G-CSF administration alters expression of glutamatergic synapse-associated proteins following cocaine-seeking behavior. Building on these findings, the present studies examined the molecular consequences of repeated administration of G-CSF, cocaine, or their combination, with a focus on glutamatergic signaling pathways. We also tested whether altered glutamate receptor expression contributes to G-CSF-mediated enhancement of cocaine reward. Repeated combined administration of G-CSF and cocaine produced robust changes in glutamate-associated and synapse-related protein expression within the nucleus accumbens and medial prefrontal cortex. These molecular adaptations were accompanied by increased synaptic density in the nucleus accumbens. Finally, pharmacological inhibition of calcium-permeable AMPA receptors within the nucleus accumbens reversed the G-CSF-induced enhancement of cocaine conditioned place preference. Together, these findings indicate that G-CSF enhances cocaine reward at least in part by promoting glutamatergic synaptic remodeling in the nucleus accumbens, identifying a neuroimmune-glutamate mechanism that may be leveraged for therapeutic intervention.

neuroscience↗

Dietary polyphenols drive alterations in behavior, transcriptional regulation, and commensal microbiota in models of opioid use.

Opioid Use Disorder (OUD) is a neuropsychiatric condition associated with tremendous medical and social consequences. Despite this burden, current pharmacotherapies for OUD are ineffective or intolerable for many patients. As such, interventions aimed at promoting overall health and resilience against OUD are of immense clinical and societal interest. Recently, treatment with a Bioactive Dietary Polyphenol Preparation (BDPP) was shown to promote behavioral resilience and adaptive neuroplasticity in multiple models of neuropsychiatric disease. Here, we assessed effects of BDPP treatment on behavioral and molecular responses to repeated morphine treatment. We find that BDPP pre-treatment alters responses across the dose range for both locomotor sensitization and conditioned place preference. Most notably, polyphenol treatment consistently reduced formation of preference at low dose (5mg/kg) morphine but enhanced it at high dose (15mg/kg). In parallel, we performed transcriptomic profiling of the nucleus accumbens, which again showed a dose x polyphenol interaction. At high dose morphine, BDPP pre-treatment potentiated gene expression changes induced by morphine particularly for genes related to synaptic function. We also profiled microbiome composition and function, as polyphenols are metabolized by the microbiome and can act as prebiotics. The profile revealed polyphenol treatment markedly altered microbiome composition and function, particularly in the low dose morphine group. Finally, we investigated involvement of the SIRT1 histone deacetylase, and the role of specific polyphenol metabolites in these behavioral phenotypes. Taken together, these results demonstrate that polyphenols have robust dose-dependent effects on behavioral and physiological responses to morphine and lay the foundation for future translational work.

neuroscience↗

Granulocyte-colony stimulating factor (G-CSF) enhances cocaine effects in the nucleus accumbens via a dopamine release-based mechanism

Cocaine use disorder is associated with alterations in immune function including altered expression of multiple peripheral cytokines in humans - several of which correlate with drug use. Individuals suffering from cocaine use disorder show altered immune system responses to drug-associated cues, highlighting the interaction between the brain and immune system as a critical factor in the development and expression of cocaine use disorder. We have previously demonstrated in animal models that cocaine use upregulates expression of granulocyte colony stimulating factor (G-CSF) - a pleiotropic cytokine - in the serum and the nucleus accumbens (NAc). G-CSF signaling has been causally linked to behavioral responses to cocaine across multiple behavioral domains. The goal of this study was to define whether increases in G-CSF alter the pharmacodynamic effects of cocaine on the dopamine system and whether this occurs via direct mechanisms within local NAc microcircuits. We find that systemic G-CSF injection increases cocaine effects on dopamine terminals. The enhanced dopamine levels in the presence of cocaine occur through a release-based mechanism, rather than through effects on the dopamine transporter - as uptake rates were unchanged following G-CSF treatment. Critically, this effect could be recapitulated by acute bath application of G-CSF to dopamine terminals, an effect that was occluded by prior G-CSF treatment, suggesting a similar mechanistic basis for direct and systemic exposures. This work highlights the critical interaction between the immune system and psychostimulant effects that can alter drug responses and may play a role in vulnerability to cocaine use disorder.

neuroscience↗

Adolescent Social Isolation Increases Vulnerability to Cocaine.

Childhood and adolescent adversity is associated with a wide range of psychiatric disorders, including an increased risk for substance abuse. Despite this, the molecular mechanisms underlying how chronic stress during adolescence alters reward signaling remains largely unexplored. Understanding how adolescent stress increases addiction-like phenotypes could inform the development of targeted interventions both before and after drug use. The current study examined how adolescent-onset isolation stress affected behavioral, molecular, and physiological responses to cocaine in male and female mice. Adolescent-onset social isolation did not alter the ability of mice to learn an operant response for food, nor influence food self-administration or motivation for food on a progressive ratio schedule. However, male and female socially stressed mice exhibited an increase in motivation for cocaine and cocaine seeking during a cue-induced reinstatement session. Additionally, we demonstrated that adolescent-onset social isolation increased cocaine-induced neuronal activation, as assessed by Fos expression, within the nucleus accumbens core and shell, ventral pallidum, dorsal bed nucleus of the stria terminalis, lateral septum and basolateral amygdala. Taken together, the present studies demonstrate that social stress during adolescence augments the behavioral responses to cocaine during adulthood and alters the responsiveness of reward-related brain circuitry.

neuroscience↗