Increased glutamic acid decarboxylase expression in the hypothalamic suprachiasmatic nucleus in depression.
In depression, disrupted circadian rhythms reflect abnormalities in the central circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN). Although many SCN neurons are said to be GABAergic, it was not yet known whether and how SCN GABA changes occur in the SCN in depression. We, therefore, studied GABA in the SCN in relation to the changes in arginine vasopressin (AVP), which is one of the major SCN output systems. Postmortem hypothalamus specimens of 13 subjects suffering from depression and of 13 well-matched controls were collected. Quantitative immunocytochemistry was used to analyze the protein levels of glutamic acid decarboxylase (GAD)65/67 and AVP, and quantitative in situ hybridization was used to measure transcript levels of GAD67 in the SCN. There were a significant 58% increase of SCN GAD65/67-ir and a significant 169% increase of SCN GAD67-mRNA in the depression group. In addition, there were a significant 253% increase of AVP-ir in female depression subjects but not in male depression patients. This sex difference was supported by a re-analysis of SCN AVP-ir data of a previous study of our group. Moreover, SCN-AVP-ir showed a significant negative correlation with age in the control group and in the male, but not in the female depression group. Given the crucial role of GABA in mediating SCN function, our finding of increased SCN GABA expression may significantly contribute to the disordered circadian rhythms in depression. The increased SCN AVP-ir in female-but not in male-depression patients-may reflect the higher vulnerability for depression in women.
['Wu|Xueyan|X|', 'Balesar|Rawien|R|', 'Lu|Jing|J|', 'Farajnia|Sahar|S|', 'Zhu|Qiongbin|Q|', 'Huang|Manli|M|', 'Bao|Ai-Min|AM|', 'Swaab|Dick F|DF|']
D000368:Aged D000369:Aged, 80 and over D001127:Arginine Vasopressin D003863:Depression D005260:Female D005968:Glutamate Decarboxylase D006801:Humans D008297:Male D012333:RNA, Messenger D012737:Sex Factors D018709:Statistics, Nonparametric D013493:Suprachiasmatic Nucleus D005680:gamma-Aminobutyric Acid
Suprachiasmatic nucleus Depression GABA Arginine vasopressin Sex difference