The changes of AgNOR parameters of anterior cingulate pyramidal neurons are region-specific in suicidal and non-suicidal depressive patients

Abstract

The anterior cingulate cortex (AC) is consistently implicated in the pathophysiology of depression. While suicide has been shown in previous reports to be closely related to depression, it is still a distinct phenomenon. The aim to differentiate between depression and suicide was approached by the karyometric analysis of AC pyramidal neurons. The study was performed on paraffin-embedded brains from 20 depressive patients (10 of whom had committed suicide) and 24 matched controls. The karyometric parameters of the layer III and V pyramidal neurons of the dorsal and ventral AC were evaluated bilaterally by Argyrophilic Nucleolar Organiser (AgNOR) silver staining method. Control-specific was the increased nuclear area in ontogenetically younger pyramidal neurons layer III in the left dorsal compared with ventral AC (Wilcoxon test, P<0.01). The decreased AgNOR number per nucleus in these cells in the right ventral AC was depression-specific compared with controls (t-test, P=0.047). On the other hand, the diffuse decrease in AgNOR ratio throughout pyramidal neurons on the left side was specific for suicidal depressive patients compared with non-suicidal patients and controls (ANOVA, P=0.028). The results suggest that regionally differentiated depression- and suicide-specific disturbed function of the most important AC output cells exists in depressive patients.

Differences between unipolar and bipolar I depression in the quantitative analysis of glutamic acid decarboxylase-immunoreactive neuropil

“…We have recently revealed in a series of publications that processes leading to suicide have an outstanding impact on the observed neurohistological abnormalities independent from the main Axis I diagnosis [18–22, 39]. This impact was also accentuated in our previous quantitative study on GAD-ir neuropil in the same cohort [21], where we found an increase in its density specific for depressed suicidal patients from the MDD and BD diagnostic groups.…”

Ribosomal DNA transcription in prefrontal pyramidal neurons is decreased in suicide

“…These are: AgNOR area (representing the nucleolus), AgNOR number (i.e. the number of AgNOR areas within one nucleus) and AgNOR ratio defined as the quotient of total AgNOR area in the nucleus and nuclear area [9][10][11][12][13][14][15][16][17][18][19][20][21][22] (for reviews see: [23,24]).…”

Post-mortem-Untersuchungen zu neuronalen Aktivierungsmustern bei depressiven Patienten

“…Wir haben diese Technik in der Depressionsforschung angewandt, um histologisch Veränderungen der transkriptionalen Aktivität von rDNA in Neuronen darzustellen (ǠTab. ; 6,21,22,24,25,27). Der Grundgedanke unserer AgNOR-Studien war, dass diese Analysetechnik hilfreich für eine vergleichende Interpretation von Post-mortem-und funktionellen In-vivo-PET-und Kernspinstudien sein könnte.…”

“…Diese waren vorwiegend suizidassoziiert und in geringerem Maß auf Unterschiede zwischen Fällen mit unipolarer bzw. bipolarer Depression zurückzuführen (21,24). Der OFK war die einzige untersuchte Hirnregion, in der suizidassoziierte AgNOR-Veränderungen geringer ausfielen, wenn die Patienten in den letzten drei Monaten vor dem Todeszeitpunkt eine Psychopharmakotherapie erhielten.…”