Abstract #3274

Styles P, Blamire A, Sharp T, Sibson N, Preece M

Few fMRI studies have directly investigated the serotonin (5-HT) neurotransmitter system, which is involved in various processes including CBF regulation, sleep, learning and mood. In this study, BOLD fMRI was use to investigate regional responses in the rat brain following administration of the 5-HT-releasing agent, d-fenfluramine, both in nave animals and after depletion of brain 5-HT levels. Significant reductions in BOLD signal were found in both cortical and subcortical regions that were mostly abolished by 5-HT depletion. In contrast, a significant increase in the BOLD response was observed in the motor cortex, which was not sensitive to 5-HT depletion.