Locus Coeruleus Is Associated with Higher Openness to Experience and IQ: Implications for the Noradrenergic System for Novelty Seeking in Daily Life

Novelty exposure and the upregulation of the noradrenergic (NA) system have been suggested as crucial for developing cognitive reserve and resilience against neurodegeneration. Openness to experience (OE), a personality trait associated with interest in novel experiences, may play a key role in facilitating this process. High-OE individuals tend to be more curious and encounter a wider range of novel stimuli throughout their lifespan. To investigate the relationship between OE and the main core of the NA system, the locus coeruleus (LC), as well as its potential mediation of IQ—a measure of cognitive reserve—MRI structural analyses were conducted on 135 healthy young adults. Compared with other neuromodulators' seeds, such as dorsal and median raphe-5-HT, ventral tegmental area-DA-, and nucleus basalis of Meynert-Ach-, the results indicated that higher LC signal intensity correlated with greater OE and IQ. Furthermore, mediation analyses revealed that only the LC played a mediating role between OE and IQ. These findings shed light on the neurobiology of personality and emphasize the importance of LC-NA system integrity in a novelty-seeking behavior. They provide a psychobiological explanation for how OE expression can contribute to the maintenance of the NA system, enhancing cognitive reserve and resilience against neurodegeneration.