EmbryoName HK026- chicken embryo- Stage 16.5 - 5.1.15
Objective To inject the youngest embryo I could find in the hopes of imaging a VIII/VII nerve complex where afferents haven't come into the hindbrain yet. Dyes of different colours on Trigeminal (DiO) vs 7/8th nerve complex (DiI) but only unilaterally because I had trouble dissecting the nerves out as they were very breakable and not as discrete branches as older ages. Procedure
- Trigeminal nerve unilaterally DiO crystals
- 7th/8th nerve unilaterally DiI crystals
Notes very poorly dissected nerve on both sides, tiny 8th nerve and very big trigeminal which I wasn't even sure whether it was attached to the hindbrain anymore, but i'm hoping that the tissue is a lot thinner and the dyes dissociate quicker on younger embryos so even if a tiny bit is attached to the hindbrain there might still be a chance that it diffuses down. Am thinking of trying to inject the otic vesicle on my next young embryo to see how that works.
Only the VII nerve on the L dyed and only 2 axons/cells were labelled. The whole nerve stub looked like the dye had diffused down it however, so that could either mean that only a very small number of efferents had left the hindbrain at that stage (16.5) however this is later than reported in the literature which indicates that it is usually around stage 14+ that the efferents exit the hindbrain. It is more likely that the dye only got through to two small cell bodies.