Evidence for an intracerebellar acetylcholinesterase-rich but probably non-cholinergic flocculo-nodular projection in the rat.

A combination of a retrograde fluorescent dye tracing technique and staining for acetylcholinesterase (AChE) after di-isopropyl-phosphorofluoridate (DFP) pretreatment was used to identify cells which project to the nodulus, flocculus or cerebellar hemisphere. Spindle-shaped AChE-rich cells in the floccular stalk project to the flocculus, nodulus and uvula, but not to the cerebellar hemispheres. Bilateral removal of the flocculi and paraflocculi, however, decreased significantly only AChE, and not choline acetyltransferase, in nodulus or uvula.