David G Wheeler | PubMed Health

PubMed2006

Localised reductions in gyrification in the posterior cingulate: schizophrenia and controls.

UNLABELLED: Several authors report changes in the volume and degree of cortical folding in several presumptive regions of schizophrenia patients. However, no research, to our knowledge, has looked for schizophrenia related differences in cortical volume and degree of cortical folding in post-mortem posterior cingulate cortex (PCCx). METHOD: Brain tissues from 9 people who suffered from schizophrenia (DSM-IV) and 9 controls were cut into 3 mm coronal slices. Three alternative PCCx blocks were available for research. The 3 PCCx blocks were cut into 50 microm sections. The volume and gyrification index (GI) were measured in 15 tissue sections per brain (5 sections per block). RESULTS: People who suffered with schizophrenia showed significant reductions in GI in rostral PCCx, trend reductions were seen in medial and caudal PCCx. In addition, the average volume of the rostral tissue sections was significantly lower in the schizophrenia cohort, suggesting that schizophrenia is associated with reduced volume in the rostral PCCx. However, a true volumetric assessment of the whole PCCx, rather than a limited number of sections from three alternative blocks, is needed to confirm such a hypothesis.

Adult↗

PubMed2006

No differences in calcium-binding protein immunoreactivity in the posterior cingulate and visual cortex: schizophrenia and controls.

UNLABELLED: Schizophrenia-specific alterations in the densities of interneurons immunoreactive (ir) to the calcium binding proteins are reported for several cortical regions. However, no reported studies have searched for such differences within the posterior cingulate cortex using antibodies to a specific calcium binding protein, calbindin (Cb). AIMS: Compare the (a) relative density of Cb-ir neurons (ratio of labeled neurons to total neurons), (b) relative width of cortical layers II/III and (c) somal areas of Cb-ir neurons in people with schizophrenia and non-psychiatric age-, gender- and postmortem index-matched controls (9 per group). METHOD: Tissue from Brodmann's area (BA) 30 and 23 and an internal control region, the visual cortex (BA 18) were labeled with polyclonal Cb antibodies then Nissl counter-stained. Cb-ir neurons as well as counter-stained neurons with clearly visible nucleoli were plotted and counted within their area 1 and laminar boundaries. RESULTS: No qualitative or statistical differences in the relative density of Cb-ir neurons were observed. A trend towards a significant effect was detected in BA 30, the relative density of Cb-ir neurons for controls was greater than for schizophrenics (P=0.0518). There were no significant differences in the relative cortical widths or somal areas. The data from this study suggest that the posterior cingulate cortex may not be involved in schizophrenia, at least not as far as Cb-ir neurons are concerned.

Adult↗