Demonstration of decreased activity of dorsal raphe nucleus neurons in depressed suicidal patients by the AgNOR staining method.
BACKGROUND
Suicide and depression are closely related yet distinct phenomena. In both these phenomena, research has focused on central serotonergic system disturbances. The dorsal raphe nucleus (DRN) is the main source of serotonergic innervation of limbic structures crucial for the regulation of emotionally influenced behaviour.


METHODS
The study was carried out on paraffin-embedded brains from 23 depressed patients (12 suicides and 11 non-suicides) and 26 matched controls without mental disorders. The karyometric parameters of DRN neurons were evaluated by the AgNOR silver staining method.


RESULTS
The significant effect of suicide on the nuclear area was found in the cumulative analysis of all DRN subnuclei (ANOVA, P=0.032). A decreased mean value of this parameter was observed in the suicides group versus controls (t-test, P=0.032). This effect was especially pronounced in the violent suicide victims (t-test, P=0.001), who also demonstrated a decreased AgNOR area versus controls (t-test, P=0.007). No significant effect of depression or polarity on AgNOR parameters was found.


CONCLUSIONS
A major limitation of this study is relatively small case number. A further limitation is given by the lack of data on drug exposure across the whole life span.


CONCLUSIONS
Our findings suggest that hypoactivity of DRN neurons is a distinct phenomenon in depression, specific only for suicidal subgroup of depressed patients.
Gos
Tomasz
T
Institute of Forensic Medicine, Medical University of Gdańsk, Poland; Department of Psychiatry, Otto-von-Guericke-University, Magdeburg, Germany. gost@amg.gda.pl
Krell
Dieter
D
Brisch
Ralf
R
Bielau
Hendrik
H
Trübner
Kurt
K
Steiner
Johann
J
Bernstein
Hans-Gert
HG
Bogerts
Bernhard
B
D000328:Adult; D000368:Aged; D001344:Autopsy; D002423:Cause of Death; D035061:Control Groups; D003866:Depressive Disorder / Q000145:classification / Q000473:pathology*; D005260:Female; D006801:Humans; D007620:Karyometry / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000473:pathology*; D009697:Nucleolus Organizer Region / Q000473:pathology*; D011903:Raphe Nuclei / Q000473:pathology*; D016622:Silver Staining / Q000379:methods*; D013405:Suicide / Q000706:statistics & numerical data*; D014754:Violence / Q000706:statistics & numerical data