Immunohistochemistry of neural markers for the study of the laminar architecture in celloidin sections from the human cerebral cortex.

Morphometric studies of the cerebral cortex in celloidin sections provide reliable quantitative estimates of cytoarchitectural features in individual brain regions. To increase our knowledge about the morphology and distribution of neuronal and glial cell types using specific cellular markers, we compared two methods of celloidin removal/antigen recovery, and subsequent immunohistochemical staining of free floating sections with specific antibodies. The method based on methanol and NaOH for celloidin removal was the most adequate for optimal recovery of immunoreactivity of the neural markers NF200, MAP2, GFAP, calretinin, parvalbumin, calbindin-D28kD, and synaptophysin. The other method, based on a treatment with ethanol/ether and formic acid, gave good results in the immunostaining of NF200, GFAP and MAP2, but not the other markers named above. The immunostained sections were compared with nearby sections stained with cresyl violet in order to assign the immunoreactive structures to individual layers in the prefrontal cortex. Sections from blocks not embedded in celloidin showed a comparable distribution of all the antigens included in the present study. The present paper provides an antigen recovery technique for celloidin sections that can be applied to optimize studies on the cytoarchitecture and distribution of specific neural elements in the human cerebral cortex.