Location and structure of the nuclei of epithalamus in hedgehog.

Studies were carried out on series of paraffin scraps stained by Nissl and Klüver-Barrera methods. Habenular complex in hedgehog divides into nucleus habenularis medialis (hm) and lateralis (hl). These centers are located between anterior edge of commissura posterior and about 180 microns in front of posterior edge of corpus callosum. Length of hm is about 2.75 mm. The medial habenular nucleus is compact, well formed and outlined group of heavily stained mainly round cells. It has diveresely placed a drop-like shape, for long distance. On the dorsal side of hm there are a small more intensively stained neurons that vary from the remaining ones. The lateral habenular nucleus is shorter and less demarcated than hm. On the cross-sections, area of hlisat least twice larger than hm but its cells are very dispersed among strong myelinated fibers This nucleus most often has the shape of vertical or oblique band of neurons that generally are larger, paler stained and heteromorphic.