Abstract #0708

Pharmacological MRI and Resting-State FMRI of Functional Brain Organization in the Serotonin Transporter Knock-Out Rat

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.