OBJECTIVE To study the neural circuits involved in regulating the strong drug-taking motivation in susceptible mice,and provide novel insights into the intervention and treatment of drug addiction.METHODS A heroin intermittent-access(Int A)self-administration model was established.Mice were divided into susceptible,unsusceptible,and non-learnt subgroups based on parameters,such as the number of times of drug infusions,effective lever presses,and breakpoints(BP)in the progres-sive ratio schedule during the drug acquisition phase.Using chemogenetic techniques,the neural projection from the orbitofrontal cortex(OFC)to the dorsomedial striatum(DMS)was selectively manipulated in the progressive ratio schedule,and its impact on drug motivation was assessed across the three subgroups.RESUITS Selectively inhibiting the OFC-DMS circuit significantly reduced the BP in susceptible mice,with no significant effect on the other two subgroups.Conversely,selective activation of this pathway significantly increased BP in susceptible mice,but had no impact on the other subgroups.CONCLU-SION The OFC-DMS circuit specifically modulates drug motivation behavior in susceptible mice,but not in the unsusceptible,and non-learnt subgroups.

OBJECTIVE To study the neural circuits involved in regulating the strong drug-taking motivation in susceptible mice,and provide novel insights into the intervention and treatment of drug addiction.METHODS A heroin intermittent-access(Int A)self-administration model was established.Mice were divided into susceptible,unsusceptible,and non-learnt subgroups based on parameters,such as the number of times of drug infusions,effective lever presses,and breakpoints(BP)in the progres-sive ratio schedule during the drug acquisition phase.Using chemogenetic techniques,the neural projection from the orbitofrontal cortex(OFC)to the dorsomedial striatum(DMS)was selectively manipulated in the progressive ratio schedule,and its impact on drug motivation was assessed across the three subgroups.RESUITS Selectively inhibiting the OFC-DMS circuit significantly reduced the BP in susceptible mice,with no significant effect on the other two subgroups.Conversely,selective activation of this pathway significantly increased BP in susceptible mice,but had no impact on the other subgroups.CONCLU-SION The OFC-DMS circuit specifically modulates drug motivation behavior in susceptible mice,but not in the unsusceptible,and non-learnt subgroups.