Kajo van der Marel1, Judith R. Homberg2, Willem M. Otte1, Rick M. Dijkhuizen1
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Donders Centre for Neuroscience, UMC St. Radboud, Nijmegen, Netherlands
Genetic variation in the serotonin transporter gene (5-HTTLPR) has been linked to various neuropsychiatric disorders, including depression and drug addiction. In this study we combined resting-state fMRI (rs-fMRI) with pharmacological fMRI (phMRI) in the serotonin transporter knock-out rat, to study the effects of disrupted serotonin homeostasis on functional organization during baseline and psychoactive stimulation. With rs-fMRI we observed positive functional connectivity among ROIs within the limbic system, but no difference with controls. With phMRI we found stronger activation responses to cocaine in knock-outs in specific limbic areas, which is in agreement with previously reported cocaine supersensitivity.