Ribosomal DNA transcription in dorsal raphe nucleus neurons is increased in residual schizophrenia compared to depressed patients with affective disorders. Issue 2 (15th December 2015)

• Record Type: Journal Article
• Authors: Krzyżanowska, Marta; Steiner, Johann; Brisch, Ralf; Mawrin, Christian; Busse, Stefan; Braun, Katharina; Jankowski, Zbigniew; Bernstein, Hans-Gert; Bogerts, Bernhard; Gos, Tomasz
• Is Part Of: Psychiatry research. Voume 230:Issue 2(2015)
• Page Start: 233
• Page End: 241
• Publication Date: 2015-12-15
• Subjects: Post-mortem -- Schizophrenia -- Depression -- Dorsal raphe -- AgNOR staining; Psychiatry -- Periodicals; Psychiatry -- periodicals; Psychiatrie -- Périodiques; 616.89
• DOI: 10.1016/j.psychres.2015.08.045
• Languages: English
• ISSNs: 0165-1781

Abstract

Abstract: The central serotonergic system is implicated differentially in the pathogenesis of depression and schizophrenia. The dorsal raphe nucleus (DRN) is the main source of serotonergic innervation of forebrain limbic structures disturbed in both disorders. The study was carried out on paraffin-embedded brains from 27 depressed (15 major depressive disorder, MDD and 12 bipolar disorder, BD) and 17 schizophrenia (9 residual and 8 paranoid) patients and 28 matched controls without mental disorders. The transcriptional activity of ribosomal DNA (rDNA) in DRN neurons was evaluated by the AgNOR silver staining method. A significant effect of diagnosis on rDNA activity was found in the cumulative analysis of all DRN subnuclei. Further analysis revealed an increase in this activity in residual (but not paranoid) schizophrenia compared to depressed (both MDD and BD) patients. The effect was most probably neither confounded by suicide nor related to antidepressant and antipsychotic medication. Our findings suggest that increased activity of rDNA in DRN neurons is a distinct phenomenon in residual schizophrenia, related presumably to differentially disturbed inputs to the DRN and/or their local transformation compared with depressive episodes in patients with affective disorders. Highlights: The dorsal raphe nucleus (DRN) is the main source of serotonergic innervation of forebrain limbic structures disturbed in schizophrenia and depression. The transcriptional activity of ribosomal DNA (rDNA) in DRN neurons was evaluated by the AgNOR silver staining method. The statistical analysis revealed an increased rDNA activity specific for residual schizophrenia versus depressed patients ( U -test, P =0.003). The observed effect could have potential diagnostic value for the differentiation between residual schizophrenia and depression if further research confirms the present results.