Study Report
Reference
| Citation | Agren, 1994 PubMed |
| Full Info | Agren, H. and Reibring, L. (1994) PET studies of presynaptic monoamine metabolism in depressed patients and healthy volunteers. Pharmacopsychiatry, 27, 2-6.
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Study
| Hypothesis or Background |
No deranged presynaptic monoamine metabolism in the brain has been directly demonstrated in mood disorders, in spite of the rich but indirect pharmacological evidence for a decreased efficacy of monoaminergic synaptic transmission in depression, especially as for serotonin.
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| Sample Information | 8 healthy volunteers and 6 patients suffering from unipolar depression |
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| Method Detail | The availability of 11C-labelled 5-hydroxytryptophan (5-HTP) and L-DOPA, the direct precursors in the synthetic pathways to serotonin and dopamine, has allowed positron emission tomographic (PET) studies in 8 healthy volunteers and 6 patients suffering from unipolar depression. |
| Method Keywords | positron emission tomography (PET) |
| Result | Main results indicate (1) decreased uptake of [11C]5-HTP and [11C]L-DOPA over the blood-brain barrier in depression (which is not altered by dietary tryptophan depletion in healthy volunteers), and (2) an increased utilization of [11C]5-HTP (but not [11C]L-DOPA), in the lower region of the medial prefrontal cortex, mainly of the left side. |
| Conclusions | This phenomenon presumably mirrors an increased synthesis of serotonin in this area and might represent a local compensatory increase in a situation of a general serotonergic hypometabolism. Analyses of interactions of both ligands between striatal and prefrontal areas suggest significantly stronger positive correlations in depression than in health, that could be interpreted as a less pronounced autonomy between brain regions in depression. |
Relationships reported by
Agren, 1994
| Component A Approved Name (Name in Paper) |
Component A Type |
Component B Approved Name (Name in Paper) |
Component B Type |
Statistical Result |
Relationship Description |
Result Category (Positive/Negative)) |
|
MDD
|
syndrome |
Serotonin (serotonin) |
molecule |
|
Decreased uptake of [11C]5-HTP (the direct precursors in the synthetic pathways to serotonin) over the blood-brain barrier in depression (which is not altered by dietary tryptophan depletion in healthy volunteers). |
Positive
|
|
MDD
|
syndrome |
Dopamine (dopamine) |
molecule |
|
Decreased uptake of [11C]L-DOPA (the direct precursors in the synthetic pathways to dopamine) over the blood-brain barrier in depression (which is not altered by dietary tryptophan depletion in healthy volunteers). |
Positive
|
|
medial prefrontal cortex (MPFC) (medial prefrontal cortex)
|
brain morphology and function |
Serotonin (serotonin) |
molecule |
|
An increased utilization of [11C]5-HTP (the direct precursors in the synthetic pathways to serotonin), in the lower region of the medial prefrontal cortex, mainly of the left side. |
Positive
|
