nf022 - chicken sb embryo - Stage 26 - 2006.10.09
Objective Facial nerve
- Right side: DiI on posterior branch of VII, DiO on VII ganglion
- Left side: DiI on gVII anglion
Notes Looks like nice labelling on both sides.
- nf022_Series006 z00-17
- nf022_Series007 z00-17
- nf022_Series014 z00-24
- nf022_Series016 z00-24
- nf022_Series022 z00-24
- nf022_Series023 z00-24
- nf022_Series038 z00-15
- nf022_Series041 z00-15
- nf022_Series048 z00-15
- nf022_Series049 z00-15
Facial Ganglion LEFT
Both rostral and caudal bundles are labelled, with caudal bundle in a more medial position. Caudal bundle seems to show a bit of a separation with a more lateral group of axons and a more medial group which is larger. In the caudal bundle, I can see the main bundle, but there are clearly axons straying towards the mdiline. the staining is also quite granular and it may be just filling pattern or the presence of growth cones or varicosities from where side branches may eventually emerge. The rostral bundle seems thinner, more fasciculated into more than one fascile and some stray axon(s) that seem to be more medial having lost their way.
Both groups of motoneurons are well labelled
Facial Ganglion RIGHT
Caudal afferents more labelled, though still some labelling on rostral afferents. Rostral afferents appear to project at least to the entry of V. Caudal axons seem to stop at the entry of IX, although some few solitary axons are seen beyond that point. Caudal afferent bundle seems to be positioned more medially, and axons show a good degree of fasciculation. There is some indication that this medial bundle might be subdivided into a larger more medial portion and a thinner more lateral portion. The lateral portion is more labelled with DiO than with DiI - and this could be a loading issue or simply a different topography. the two bundles of the caudal bundle seem to come together to criss-cross each other at the level of about r7. It reminds me of the embryonic lumbar plexus.
Both motoneuron groups are labelled quite well.
In the merged image of ganglion and posterior branch, ti seems that there is a good deal of overalp between green and red in the medial side of the caudal afferent bundle, whereas more laterally it looks like there is more segregation between read and green. They seem less segregated in the rostral afferent bundle.
Posterior facial branch (RIGHT)
Don't seem to have much afferent label, there might be some, but nothing compared to when the ganglion is labelled. The caudal bundle axons are very varicose.
Both groups of motoneurons seem to be labelled. There seems to be some sort of disorganisation of the efferent axons towards the border of r5/r6 (see nf022_FreeProjMax_05_ch00.tif. There is something definitely going on at that border, but cannot make out what that is.