The striatum, especially the nucleus accumbens (NACC), is one of the key brain regions of the reward system accounting for emotion and motivation. It is also one of the hotspots correlating with anhedonia, the reduced capacity to experience pleasure, in patients with schizophrenia and other mental disorders. Genetic studies also suggest that activation of the NAcc is influenced by genetic factors. However, it is still not clearly understood which genetic factors influence NAcc and ventral striatal brain activations during the anticipation of rewards.
To investigate this issue, Professor Raymond Chan from the Neuropsychology and Applied Cognitive Neuroscience (NACN) Laboratory and the Chinese Academy of Sciences Key Laboratory of Mental Health and international collaborators have utilized a healthy twin study design to examine whether motivation-related NAcc activation and pleasure experience would exhibit significant heritability. They administered a functional magnetic resonance imaging-based Monetary Incentive Delay task to 86 healthy monozygotic twins and 88 dizygotic twins when they anticipated monetary incentives. Moreover, the participants were required to complete a set of self-reported measures of pleasure experience. Using a voxel-wise heritability mapping method, they found that activation of the bilateral NAcc during the anticipation of monetary gains was significantly heritable (h2 = 0.20-0.49). Moreover, significant shared genetic covariance was observed between pleasure experience and NAcc activation during the anticipation of monetary gain. Quantifying the heritability of brain activation in anticipating monetary incentives could facilitate the understanding of the influence of genetic factors on reward processing and the detection of associated genetic loci, which may further the understanding of the neurobiological basis of mental disorders such as schizophrenia.
This study was supported by grants from the National Basic Research Programme of China (Precision Psychiatry Programme), the National Science Foundation China, the Beijing Training Project for Leading Talents in S&T, the Beijing Municipal Science & Technology Commission Grant, and the CAS Key Laboratory of Mental Health, Institute of Psychology.
This study has been published online in Psychological Science:
Li, Z., Wang, Y., Yan, C., Cheung, E. F., Docherty A. R., Sham, P. C., Gur, R. E., Gur, R. C., Chan, R. C. K.* (2019). Inheritance of neural substrates for motivation and pleasure experience. Psychological Sciences. 30(8),1205-1217. DOI: 10.1177/0956797619859340
Institute of Psychology