Somal size of prefrontal cortical pyramidal neurons in schizophrenia: differential effects across neuronal subpopulations.
BACKGROUND
Cognitive dysfunction in schizophrenia may be related to morphologic abnormalities of pyramidal neurons in the dorsal prefrontal cortex (dPFC) and the largest pyramidal neurons in deep layer 3 may be most affected. Immunoreactivity (IR) for the nonphosphorylated epitopes of neurofilament protein (NNFP) identifies a subset of large dPFC deep layer 3 pyramidal neurons. We tested the hypotheses that the average size of NNFP-IR neurons is smaller in schizophrenia and that the decrease in size of these neurons is greater than that observed in the general population of deep layer 3 pyramidal neurons.


METHODS
We estimated the mean somal volume of NNFP-IR neurons in deep layer 3 of 9 in 13 matched pairs of control and schizophrenia subjects and compared the differences in somal size of NNFP-IR neurons to the differences in size of all deep layer 3 pyramidal neurons identified in Nissl-stained material.


RESULTS
In subjects with schizophrenia, the somal volume of NNFP-IR neurons was nonsignificantly decreased by 6.6%, whereas that of the Nissl-stained pyramidal neurons was significantly decreased by 14.2%.


CONCLUSIONS
These results suggest that the NNFP-IR subpopulation of dPFC pyramidal neurons are not preferentially affected in schizophrenia. Thus, a subpopulation of dPFC deep layer 3 pyramidal neurons, other than those identified by NNFP-IR, may be selectively vulnerable in schizophrenia.
Pierri
Joseph N
JN
Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Volk
Christine L E
CL
Auh
Sungyoung
S
Sampson
Allan
A
Lewis
David A
DA
D000328:Adult; D000368:Aged; D001344:Autopsy; D016022:Case-Control Studies; D002452:Cell Count; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016900:Neurofilament Proteins / Q000032:analysis; D017397:Prefrontal Cortex / Q000473:pathology*; D017966:Pyramidal Cells / Q000473:pathology*; D012559:Schizophrenia / Q000473:pathology*
D016900:Neurofilament Proteins