PET neuroimaging of clomipramine challenge in humans: focus on the thalamus.
PET neuroimaging of serotonin responsivity relied previously mainly on fenfluramine, but that drug has been withdrawn from the market. Therefore, we determined whether clomipramine, which stimulates serotonergic mechanisms by inhibiting serotonin reuptake, has reliable effects in the healthy human brain as measured by [15O]H2O PET. The clomipramine challenge markedly reduced the relative rate of blood flow in the selected region of interest, namely the dorsomedial nucleus of the thalamus, a limbic region rich in serotonin uptake sites. These findings show similarities between effects of fenfluramine and clomipramine in the healthy human brain, and support the use of the clomipramine challenge in conjunction with PET for studying cerebral serotonergic mechanisms.
Smith
D F
DF
Institute for Basic Research in Psychiatry, Department of Biological Psychiatry, Psychiatric Hospital of Aarhus University, 8240 Risskov, Denmark. dfsmith@inet.uni2.dk
Geday
J
J
D000368:Aged; D002997:Clomipramine / Q000494:pharmacology*; D006801:Humans; D020645:Mediodorsal Thalamic Nucleus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D010104:Oxygen Radioisotopes / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013788:Thalamus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D014055:Tomography, Emission-Computed / Q000379:methods*; D014867:Water
D002997:Clomipramine; D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors; D014867:Water