Dopaminergic abnormalities in amygdaloid nuclei in major depression: a postmortem study.
BACKGROUND
A deficiency of mesolimbic dopamine (DA) is a leading candidate for the etiology of certain symptoms of depression (e.g., anhedonia and loss of motivation). Here we show amounts of dopaminergic proteins in the amygdala, a key brain structure involved in the integration of emotions and stress, in subjects with major depression and in psychiatrically normal control subjects.


METHODS
The specific binding of [(125)I]RTI 55 to the DA transporter, [(3)H]SCH 23390 to the D1 receptor and [(125)I]epidepride to D2/D3 receptors were measured in the right amygdaloid complex in postmortem brains from 11 subjects with major depression and 11 matched control subjects.


RESULTS
The binding of [(125)I]RTI 55 to DA transporter was significantly lower in the basal and central amygdaloid nuclei, whereas the binding of [(125)I]epidepride to D2/D3 receptors was significantly higher in the basal, central, and lateral amygdaloid nuclei in major depression compared with control subjects. No difference in the binding of [(3)H]SCH 23390 to D1 receptors was observed.


CONCLUSIONS
Given that DA depletion in rats can induce a reduction in the DA transporter and an upregulation of D2/D3 receptors, our data are consistent with the hypothesis that major depression is associated with a deficiency of mesolimbic DA.
Klimek
Violetta
V
Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson 39216, USA.
Schenck
Jane E
JE
Han
Hui
H
Stockmeier
Craig A
CA
Ordway
Gregory A
GA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000679:Amygdala / Q000378:metabolism* / Q000473:pathology; D001345:Autoradiography; D003865:Major Depressive Disorder / Q000378:metabolism* / Q000473:pathology; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D011869:Radioligand Assay; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D050637:Receptors, Dopamine D3
C493593:DRD3 protein, human; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D004298:Dopamine