We found significantly increased tyrosine hydroxylase (TH) in the LC of MDD patients-thus validating the method-but not in BD patients, and we did not find significant changes in the receptor tyrosine-protein kinase ErbB4 in the LC in MDD or BD patients.
Lower DAT levels (and tyrosine hydroxylase) in the putamen of MDD compared with healthy controls were replicated in postmortem analyses (Cohen d range, -0.92 to -1.15).
Our results suggest that the biosynthetic pathways of the monoamine neurotransmitters that are mediated by TH and GCH might be associated with the CFS clinical findings, because persistence is one of the typical personality traits observed in CFS and patients with major depressive disorder exhibit a higher harm avoidance score.
Our results suggest that the biosynthetic pathways of the monoamine neurotransmitters that are mediated by TH and GCH might be associated with the CFS clinical findings, because persistence is one of the typical personality traits observed in CFS and patients with major depressive disorder exhibit a higher harm avoidance score.
Long-term changes in catecholamine levels and expression of their biosynthetic enzymes are associated with several stress-related disorders such as elevated plasma norepinephrine in posttraumatic stress disorder and increased postmortem tyrosine hydroxylase in the locus coeruleus with major depression.
In our study, medication-free subjects with fully remitted major depression underwent a paradigm of catecholamine depletion, via use of the tyrosine hydroxylase inhibitor alpha-methylparatyrosine.
In the light of data that major depression is associated with an activation of brain CRH and LC-NE systems, the time-dependent effect of long-term imipramine administration on decreasing the gene expression of CRH in the hypothalamus and TH in the LC may be relevant to the therapeutic efficacy of this agent in depression.