1.Probabilistic Tractography Between Nucleus Accumbens and Other Reward-related Brain Areas in Malay Female Adolescents
Siti Hajar Zabri ; Asma Hayati Ahmad ; Rahimah Zakaria ; Aimi Nadhiah Abdullah ; Siti Fatimah Mukhtar ; Jafri Malin Abdullah
Malaysian Journal of Medicine and Health Sciences 2023;19(No.2):61-68
Introduction: Studies show that adolescents are more reward sensitive compared to other age groups. The nucleus accumbens (NAcc) has been identified as a key brain area involved in reward through its connectivity to other
reward-related brain areas. Our study aimed to characterise the white matter structural connectivity of nucleus accumbens with brain areas that are most often associated with reward in female adolescents. Methods: Fifteen healthy
female Malay adolescents were recruited and underwent diffusion-weighted brain scanning. Two behaviour scales
were also given to verify typical reward responsiveness. Then, probabilistic tractography and NAcc segmentation
were performed on the data using FMRIB Software Library (FSL). Probabilistic tractography was performed to determine the relative connection probability of nucleus accumbens (NAcc) to areas shown to be associated with reward,
namely amygdala, anterior cingulate cortex (ACC), medial orbitofrontal cortex (mOFC), hippocampus, ventrolateral
prefrontal cortex (vlPFC) and dorsolateral prefrontal cortex (dlPFC). Connectivity-based segmentation of NAcc was
performed to determine the spatial distribution of its connectivity with the target brain areas according to the highest
connection probability. Results: The highest relative connection probability was found between NAcc to mOFC,
while the NAcc parcellation showed the widest distribution of connection to mOFC compared to the other five targets on both sides of the brain. Conclusion: Our findings demonstrated the strongest structural connectivity and widest distribution between NAcc and mOFC compared with other brain areas related to reward. This study’s findings
could be used as baseline to compare with people with atypical reward circuit problems.