THE DISTINCT ROLE OF GLIA CELL IN DRUG ADDICTION

Background and Aim : Despite vast majority of clinical and preclinical research in the terms of addiction, drug abuse still remains an intractable and costly disorder affecting society as well as individuals. Although drug-induced alterations in neuronal function remain prominent theory of addiction, accumulating evidence suggests undeniable role of glia cells in brain plasticity related to substance abuseMethods : Recent studies have to dissect the role of glial cells in addiction. Initial in vitro studies on the effects of opiates on oligodendroglial cells found that not only do oligodendroglial cells express the opioid receptors, but opiates have differential effects on cellular processes, including mitogenesis, DNA synthesis, and chromatin remodeling. oligodendrocyte progenitor cell has been reduced through short and longterm access of amphetamines in mPFC, whereas increases the expression of oligodendrocyte lineage genes has been seen in opiate addiction.Results : Microglia have been considered the resident immune cells of the brain and spinal cord. Drugs of abuse could influence glia directly through interactions at surface receptors sensitive to these natural or synthetic compounds, or indirectly through their effects on neighboring neurons surveyed by microglia or astrocytes. Using positron emission tomography(PET) and the radioligand to measure microglial activity, the brains of abstinent methamphetamine abusers showed evidence of reactive microgliosis in the midbrain, striatum, thalamus, and the orbitofrontal and insular cortices Astrocytes have been characterized as supportive cells in the brain. The astrocytic role in addiction appears to involve altered d-serine and l-lactate signaling, which in turn perturbs physiological synaptic plasticity and memory. cocaine alters glutamatergic function in the NAc by modifying the AMPA receptor/NMDA receptor currents ratio and by impairing LTP and LTD. As astrocytes influence glutamatergic transmission in the NAc, they could participate in these changes. Cannabis-induced disruption of working memory also appears to be astrocyte-mediated. Study on Δ 9-tetrahydrocannabinol has been revealed that astrocytic, not neuronal, CB1Rs are essential mediators of both the plasticity and behavioral memory effects of THC. Conclusion : In conclusion, this renewed focus on glia represents a necessary step in the continued elaboration of the deeply complex network of cells involved in motivation and addiction

کلیدواژه ها:

drug abuse ، glia ، astrocyte ، microglia