Cell bodies and axons of the mesencephalic

trigeminal nucleus in a 4 day old chick embryo. The trigeminal nucleus is made up of scatered neurons along the midline of the optic tectum. This picture shows the optic tectum from the back. The axons were labelled on one side only. Mesencephalic trigeminal neurons are unusual in that they are primary sensory neurons (probably derived from neural crest) that develop within the central nervous system. Biomedical Image Awards 1999.