No evidence for a role of the serotonin 4 receptor in five-factor personality traits: A positron emission tomography brain study

• Published in: PloS one Vol. 12; no. 9; p. e0184403
• Main Authors: Stenbæk, Dea Siggaard, Dam, Vibeke Høyrup, Fisher, Patrick MacDonald, Hansen, Nanna, Hjordt, Liv Vadskjær, Frokjaer, Vibe Gedsoe
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07.09.2017; Public Library of Science (PLoS)
• Subjects: Adult; Aged; Aged, 80 and over; Amygdala; Amygdala - metabolism; Analysis; Binding; Biology and Life Sciences; Brain; Brain architecture; Brain research; Cortex; Cortex (cingulate); Emission analysis; Emissions; Female; Females; Five-factor personality model; Genotype; Gyrus Cinguli - metabolism; Hippocampus - metabolism; Humans; Male; Medical imaging; Medicine; Medicine and Health Sciences; Metabolism; Middle Aged; Neocortex - metabolism; Neurobiology; Neuroimaging; Neurosciences; Personality; Personality - physiology; Personality traits; Positron emission; Positron emission tomography; Positron-Emission Tomography - methods; Psychological aspects; Psychopathology; Receptors, Serotonin, 5-HT4 - metabolism; Regional analysis; Regression analysis; Regression models; Research and Analysis Methods; Serotonin; Serotonin receptors; Serotonin S4 receptors; Social Sciences; Studies; Tomography; Young Adult; Denmark
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0184403

Serotonin (5-HT) brain architecture appears to be implicated in normal personality traits as supported by genetic associations and studies using molecular brain imaging. However, so far, no studies have addressed potential contributions to variation in normal personality traits from in vivo serotonin 4 receptor (5-HT4R) brain availability, which has recently become possible to image with Positron Emission Tomography (PET). This is particularly relevant since availability of 5-HT4R has been shown to adapt to synaptic levels of 5-HT and thus offers information about serotonergic tone in the healthy brain. In 69 healthy participants (18 females), the associations between personality traits assessed with the five-factor NEO Personality Inventory-Revised (NEO PI-R) and regional cerebral 5-HT4R binding in neocortex, amygdala, hippocampus, and anterior cingulate cortex (ACC) were investigated using linear regression models. The associations between each of the five personality traits and a latent variable construct of global 5-HT4R levels were also evaluated using latent variable structural equation models. We found no significant associations between the five NEO personality traits and regional 5-HT4R binding (all p-values > .17) or the latent construct of global 5-HT4R levels (all p-values > .37). Our findings indicate that NEO personality traits and 5-HT4R are not related in healthy participants. Under the assumption that global 5-HT4R levels index 5-HT tone, our data also suggest that 5-HT tone per se is not directly implicated in normal personality traits.