Dear Natacha,

I have not tried this myself but since I have thought about it I may suggest you to try it. I dont know any marker for the parallel fibers, but what you can use is DAPI which works at very dilute concentrations of around 1:10000 and labels all the nuclei, within 10 minutes or so. Once you label the cellular nuclei that may give you a differential idea about the fiber tracts. Just an idea anyway.

I would imagine that the parasagittal sections would be better for parallel fibers. Parasagittal sections will give you nice image of Purkinje cells and their processes (check the parasagittal images in papers below). In JCN paper in Fig 2, you can compare parasagittal vs transverse images of cerebellar sections in the adult rat. In NeuroReport paper in Fig2I, and 12c in JCN paper you can almost make up the parallel fibers at the distal dendrites of Purkinje cells.

best wishes,

Refik

Article Localization of ATP-gated ion channels in cerebellum using P...

Article Distribution of the P2X2 receptor subunit of the ATP-gated i...

thanks a lot for your reply and your suggestions.

Dear Natacha,

If you want to see a long stretch of PF (intervaricosity distance study ?) a coronal or transversal section seems more appropriate than parasagital. As for marker, you probably do not want to label ALL the PFs, it would become too messy to see anything. I would suggest to place a very small DiI crystal on the GL or inject the GL of your fixed slice with a bolus of Fast-red (slightly less lipophilic than DiI). If the crystal/bolus is small enough and you if you leave your slices rest at 10C long enough (w/ azide?) you should get a subset of brightly stained PF. I hope this helps. Good luck