Acute Effect Of Buprenorphine On Brain FMRI Response To Drug-Related Cues Of Heroin Addicts

Functional MRI (fMRI) is a study technology which can be used to observe functional and metabolic activity in living subject with MRI , it has been widely applied in neuroscience research . In fact , the extensive conception of functional MRI includes not only BOLD technology,but also contains multiple techniques which can be used to observe functional and metabolic activity in vivo ,sunch as CBF , CBV , MRS , DWI/DTI , MEMRI and so on .Pharmacological MRI (phMRI) is a special application of functional MRI , which primarily investigates the pharmacological mechanism in living animal model and human . The application of pharmacological MRI is broad , including Neurotransmitter systems , neurology and psychiatry , drug abuse and addiction , inspecting progress of disease , evaluation of curative effect , discovery of new drug , individuality of medication .Drug addiction is a chronic disease , and now the main treatment to it is the substitutable medication . But these medication can not thoroughly heal drug addiction at present , by reason of the persistence of relapse . So it is necessary to find new targets of the clinical treatment of drug addiction . To this aim , it is essential to disclose the neurobiological mechanism of drug addiction .This study employs the phMRI model combining drug with cognitive task , to investigate acute effect of buprenorphine on brain fMRI response to drug-related cues of heroin addicts .The outcome of this study will be meaningful to guide clinical crue and new drug discovery of heroin addiction .The results of this study show , comparing the two courses between the prophase(10-45minutes after medication ) and the anaphase (60-100minutes after medication )after sublingually of buprenorphine( 0.5mg ) , the brain fMRI response to drug-related cues of heroin addicts is bipolar .The activation intensity of left cingulate gyrus and left midbrain in the anaphase after sublingually of buprenorphine is lower than the prophase . These two brain regions are the chief component of midbrain- limbic(mesocorticolimbic)system ,which has important role in reward circuit ,motivation circuit ,control circuit . On the contrary , the activation intensity of right prefrontal lobe in the anaphase after sublingually of buprenorphine is stronger than the prophase . The prefrontal lobe is the vital brain region in charge of advanced cognitive function ,and it is also involved in decision making and in inhibitory control .The mesocorticolimbic system is potentially involved in the first level"craving"derived from malfunction of motivation and control ,and it mainly avoid negative withdrawal syndrome . So the first level"craving"is just a kind of inferior neural activity .The prefrontal lobe is potentially involved in malfunction of motivation and control about the second level"craving", which primarily aimed at pursuing euphoria , demanding more advanced cognitive neural function .