The Therapeutic Effect Of Deep Brain Stimulation On Anterior Insula In Drug Addiction And Its Related Mechanism

Part 1: Continuous high frequency deep brain stimulation of the rat anterior insula attenuates the relapse post withdrawal and strengthens the extinction of morphine seekingObjective Deep brain stimulation(DBS)modulates the neuronal activity in specific brain circuits and has been recently considered as a promising intervention for refractory addiction.The insula cortex is the hub of interoception and is known to be involved in different aspects of drug addiction.In the present study,we investigate the effects of continuous high frequency DBS in the anterior insula(AI)on drug-seeking behaviorsMethods Sprague-Dawley rats were trained to the morphine-conditioned place preference(CPP,day 1-8)followed by bilaterally implanted with DBS electrodes in the AI(Day 10)and recovery(Day 10-15).Continuous high-frequency(HF)-DBS(130Hz,150μA,90μs)was applied during withdrawal(Day 16-30)or extinction sessions.CPP tests were conducted on days 16,30,40 during withdrawal session.Following the complete extinction,morphine-CPP was reinstated by a priming dose of morphine infusion(2mg/kg).The open field and novel objective recognition tests were also performed to evaluate the DBS side effect on the locomotion and recognition memory.Results Continuous HF-DBS in the AI attenuated the expression of morphine-CPP post-withdrawal(Day 30),but morphine addictive behavior relapsed ten days after the cessation of DBS(Day 40).Continuous HF-DBS reduced the period to full extinction of morphine-CPP and blocked morphine priming-induced recurrence of morphine addiction.HF-DBS in the AI had no obvious effect on the locomotor activity and novel objective recognition and did not cause anxiety-like behavior.Conclusion Continuous HF-DBS in the bilateral anterior insula prevents the relapse of morphine place preference after withdrawal,facilitates its extinction,blocks the reinstatement induced by morphine priming.Our findings suggest that manipulation of insular activity by DBS could be a potential intervention to treat drug addiction,although future research is warranted.Part 2: iTRAQ proteomic analysis of the anterior insula in morphine-induced conditioned place preference rats with high frequency deep brain stimulation interventionObjective Morphine dependence or addiction is a serious global public health and social problem,and traditional treatments are very limited.Deep brain stimulation(DBS)has gradually become a new treatment for drug addiction.In view of repeated use of morphine leading to neuroadaptive and proteomic changes in the addiction-related brain regions or nuclei,proteomics and related proteins of insula and DBS intervention therapy in insula after morphine addiction withdrawal will be studied in this study.Methods The rats were trained to morphine conditioned palace preference and then implanted bilaterally with electrodes in anterior insula,recovered for 5 days.The morphine conditioned place preference(CPP)was also established in the rats without DBS device implanting.These rats underwent abstained from morphine for 14 days and chronic continuous high frequency electrical stimulation was applied during the withdrawal phase.On the fifteenth day post withdrawal,all animals conducted CPP tests and proteomics analysis of the rat anterior insula was performed using isobaric tags for relative and absolute quantitation labeling(iTRAQ)coupled with 2D-LC MS/MS and Parallel reaction monitoring(PRM).Results 8-day morphine injection in alternative induced morphine CPP and chronic continuous high frequency DBS prevented the relapse of morphine preference.A total of 5575 proteins were identified.Relative to the saline group,the morphine group showed 14 down-regulated and 3 up-regulated proteins.118 proteins increased and 87 proteins decreased between DBS implanted animals and morphine group.Based on Gene Ontology enrichment an KEGG pathway analyses the majority of these differentially expressed proteins(DEPs)were found related to protein metabolic process,G-protein coupled receptor signaling pathway,calcium-mediated signaling,neurotransmitter transport,dopaminergic synapse,m TOR signaling pathway.Importantly,6 down-regulated and 2 up-regulated proteins in morphine group versus saline group were reversed after DBS intervention therapy.Three interested proteins were confirmed by PRM.Conclusion Our study identifies several proteins and cellular signaling pathways potentially involved in the molecular mechanisms in the insula that underlie morphine addiction and provides a comprehensive understanding of the proteomic changes associated with morphine addiction and HF-DBS therapy in addicted animal models,which is helpful for the development of DBS intervention in drug addiction.Gnal,GLT-1 and Taco1 may be targets for the treatment of drug addiction.