The serotonin-dopamine interaction measured with positron emission tomography (PET) and C-11 raclopride in normal human subjects
- Brookhaven National Lab., Upton, NY (United States); and others
Our previous studies have shown that the interaction between serotonin and dopamine can be measured with C-11 raclopride and PET in the baboon brain. A series of studies was undertaken to extend dim findings to the normal human brain. PET studies were conducted in male control subjects (n=8) using the CTI 931 tomograph. Two C-11 raclopride scans were performed, prior to and 180 minutes following administration of the selective serotonin releasing agent, fenfluramine (60mg/PO). The neuroendocrine response to fenfluramine challenge is commonly used in psychiatric research as an index of serotonin activity. The C-11 raclopride data were analyzed with the distribution volume method. For the group of subjects, an increase was observed in the striatum to cerebellum ratio (specific to non-specific binding ratio), in excess of the test-retest variability of the ligand. Variability in response was observed across subjects. These results are consistent with our previous findings in the baboon that citalopram administration increased C-11 raclopride binding, consistent with a decrease in endogenous dopamine. In vivo microdialysis studies in freely moving rats confirmed that citalopram produces a time-dependent decrease in extracellular dopamine levels, consistent with the PET results. In vivo PET studies of the serotonin-dopamine interaction are relevant to the evaluation of etiologic and therapeutic mechanisms in schizophrenia and affective disorder.
- OSTI ID:
- 197956
- Report Number(s):
- CONF-940605--
- Journal Information:
- Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.5 Vol. 35; ISSN 0161-5505; ISSN JNMEAQ
- Country of Publication:
- United States
- Language:
- English
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