Fig. 2: Binding potential in the dorsal raphe nucleus modulates social learning and competitive behavior.
From: Regulation of social hierarchy learning by serotonin transporter availability
A Statistical map of the average BPND revealed a large distribution in the striatum and DRN. The white shape represents the DRN ROI. The bar graph represents the mean binding potential extracted in the DRN, ventral striatum left and right, amygdala left and right, and anterior PFC for illustration purposes. All extractions were performed using the ROI defined with the AAL3. B Left. Participants’ choice frequency during the social dominance learning task (dots) when facing the Inferior (green), Intermediate (orange), and Superior (red) opponents and model choice probability estimated by the RL algorithm. Right. Same illustration for the RL task. task. C Negative correlation between the BPND DRN, and participants’ learning rate in the social task. No correlation was observed between BPND, DRN and learning rate in the non-social task. D Competitive behavior related to the SERT level in the DRN. Competitive choices in the High and Low BPND groups. Individuals with lower BPND, in the DRN tended to increase their competitive choices, i.e. they chose to play against the stronger of the two opponents, in later trials. Interaction between trial bins and group (Low vs high BPND resulting from the median split) (F(1,5) = 4.41, p = 0.037). Post-hoc tests conducted on the last bin revealed that the high BPND group made less competitive choices in the last bin of the task (Median rank = 18.87) compared to the low BPND group (Median rank = 12.13) (p = 0.036). The bar graphs show a between-groups difference in BPND level in the DRN based on a median split of individuals. Errors bars represent SEM. ***p < 0.001. BPN non-displaceable binding potential, DRN dorsal raphe nucleus, RL reinforcement learning.
