Sagittal Sections of an E10.5 Stage 36 Chick Embryo

 This atlas depicts sagittal sections through the developing brain and head of a Hamburger and Hamilton stage 36 (Embryonic day 10.5 or E10.5) white leghorn chick embryo.  The work was carried out under ethical approval from the University of New South Wales Animal Ethical Committee.

The embryo was fixed by immersion in room temperature Bouin’s fluid for 24 hours before dehydration in graded ethanol and xylene and embedding in paraffin.  The block was sectioned in a sagittal plane at a thickness of 10 µm and the sections mounted on glass slides.  Sections were stained with hematoxylin and eosin and coverslipped with DePeX.

 Six equally spaced sections through the embryo’s head and neck were photographed with the aid of a Zeiss Axiophotphotomicrographic system and a Canon EOS 400D body.  Images were placed in Adobe Illustrator 2021 and delineated.

Developmental segmentation (neuromeres) of the rhombencephalon (rhombomeres, r1, r2 etc) have been depicted where visible.  Delineation of the telencephalon is based on zones identified for the adult chicken brain by Puelles et al. (2007).

Large font names (e.g. Telen, Mesen, Myelen,) indicate large-scale regions.

Scale bars indicate distances on the dehydrated and embedded embryo.

References

Puelles L, Martinez-de-la-Torre M, Paxinos G, Watson C, Martínez S. (2007) The Chick Brain in Stereotaxic Co-ordinates. An Atlas featuring Neuromeric Subdivisions and Mammalian Homologies. Academic Press.