How to recover single cells from CNS tissue ?

[Berend Rah]

Hello,

I have a problem; I would like to isolate single cells from CNS-tissue 
(medulla/upper spine) to isolate RNA from them. I am looking for a special 
group of neurons which can only be reliably identified after staining a tissue 
section. Therefore, I would like to know the following: 

I. Which staining techniques do not (much) deteriorate the quality of RNA ?
II. Shall/can the tissue be fixed beforehand or is pure freezing preferable ?
III. How to isolate the identified cells from the tissue slices ?

If anyone should know a better way to tackle this issue please let me also 
know. I will highly appreciate any suggestions and ideas regarding my problem.

Best regards, Berend