Developing Henna‐Haematoxylin stain as alternative to Nissl stain in delineating the cytoarchitecture of the neocortex and archicortex of the cerebrum

Demonstration of neuronal distribution patterns such as cerebral cortical layers or zones of neuronal cell loss usually requires specific stains such as Nissl stains which are not easily obtainable in developing countries. This study aims at testing henna as a counterstain to haematoxylin in delineating the cortical layers in the cerebrum. Paraffin‐embedded serial sections (5μm) of cerebral cortex of Wistar rat fixed in Bouin's fluid and stained with haematoxylin and henna (0.5% w/v aqueous crude extract of Lawsonia inermis leaves dissolved in 5% aqueous alcohol and mordanted with potassium alum) was observed to be effective in mapping out the six cortical layers of the neocortex and the three layers of the archicortex distinctly. It also stained the cytoplasm of the perikarya and glial cells brown and in addition demonstrated the thalamic nucleus in the central core of the cerebrum as a dense aggregation of neuronal cell bodies criss‐crossed by bundles of fibres. Thus, henna used as a counterstain to haematoxylin demonstrated reliability as a neurological stain to delineate the cellular layers in the archicortex (hippocampus) and the neocortex and therefore could serve as a readily available and cheaper alternative to Nissl stains for developing or third world countries. Grant Funding Source : Ahmadu Bello University Research Grant