Impairment of value-based decision-making in morphine-dependent rats is partly related to neural connectivity between the anterior cingulate cortex and basolateral amygdala.

Abstract

Previous studies have established that the amygdala specifically the basolateral amygdala (BLA), has a fundamental role in decision-making. The present study aimed to investigate functional and neural synchronization between the BLA and anterior cingulate cortex (ACC) while making effort-choice decisions regarding pre-morphine dependence and morphine dependence times. A T-maze decision-making task with a differential outlay (great vs. small effort) and benefit (great vs. small reward) was done, and local field potentials from the BLA and ACC were assessed simultaneously. Results illustrated that in pre-morphine dependence time, when the animals made great reward/great effort decisions, there was a neural synchronization between both regions in beta and gamma frequency bands; and also, in delta, theta, beta, and gamma frequencies while expending effort and climbing the barrier. However, in morphine-dependent rats, during low reward/low effort choice and also during expending low effort, there was just a weak neural coherence in gamma frequency. Besides, there was neural synchronization in theta, beta, and gamma frequencies during reaching great reward in pre-morphine dependence time. Nevertheless, during reaching low reward in morphine dependence time, there was a weaker coherence in beta and gamma compared to pre-morphine dependence. These findings showed that functional and neural coherence between the BLA and ACC has a fundamental role in making the effort-based decision and expending effort. Preference for low reward/low effort, and decrease in expending effort in morphine-dependent rats is partly associated with the changes in the neural coherence between the BLA and ACC.