Investigation of markers to estimate numbers of neurons and glial cells in human myenteric ganglia

An important requirement in pathological diagnostics in the human enteric nervous system (ENS) is the estimation of the total numbers of neurons and glial cells.While myenteric ganglia wholemounts are the best preparations for total cell counting, archivial wax-embedded samples are often the only available material. In order to obtain valid counting of myeteric ganglia cells on paraffin sections, detailed morphological studies are required taking into account some technical notes. To examine the number of myenteric neurons and glial cells in paraffin sections in human colon. Normal colon specimens were obtained from 8 controls undergoing surgery for colon cancer.The myenteric ganglia were evaluated in paraffin serial cross-sections: CB, HuC/D and NFL or S100 and GFAP stainings were used to examine body numbers of neural and glial cells, respectively.The suitability of two neuronal markers, CB and HuC/D, was compared for staining and counting human myenteric neurons: 89.5% of all neurons were HuC/D-reactive (85.6% double-labelled, 3.9% immunostained only with HuC/D) whereas 10.5% were stained only for CB.The expression of NFL was correlated with HuC/D: 50.0% of all neurons were NFL-reactive and only 39.5% were NFL/HuC/D double stained. Thus both markers, CB and HuC/D, were comparably reliable in representing the total myenteric neurons and S100 detection allowed a better evaluation of glial cell bodies than GFAP did.The number of estimated myenteric cells is comparable to that reported in wholemount preparations thus confirming the validity of these evaluations on sections from archivial colon paraffin-wax blocks.