An evaluation of the role of the noradrenergic system in the neurobiology of depression: a review

✍ Scribed by Anna M. Redmond; Brian E. Leonard

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 275 KB
• Volume: 12
• Category: Article
• ISSN: 0885-6222
• DOI: 10.1002/(sici)1099-1077(199709/10)12:5<407::aid-hup918>3.0.co;2-1

✦ Synopsis

With increased understanding of the neurobiology of depression, the role of the noradrenergic system is achieving greater signi®cance. Unfortunately, the exact role of noradrenaline in depressive disorders is dicult to determine due to contradictory and inconsistent results from metabolite (MHPG) and receptor (a-and b-adrenoceptors) binding studies which appear to be due to dierences in experimental methods and variations between the age of tissue samples and the patient groups being studied. The role of tyrosine hydroxylase, the rate-limiting enzyme in the synthesis of noradrenaline has only recently been explored. A downregulation of tyrosine hydroxylase mRNA expression seems to be a common mechanism of action of antidepressant treatments and indicates that the site of action of antidepressants may occur at the level of gene expression. Evidence suggest that corticotrophin releasing factor (CRF) may regulate tyrosine hydroxylase activity and so may provide a link between the monoamine and endocrine theories of depression. Glutamate and sigma receptors have also been implicated in having a role to play in aective disorders and will be discussed in this review as these receptors may be indirectly involved in modulating the activity of the noradrenergic system.