You want to ' know how long it could be in the brain cells' ok , you may see the presence of drug in blood-serum, CSF or you have to do tagging with radio isotope and observe the presence in imaging NMR, PET Scan.

Thank you Dr. Lavekar. idea looks great but I don't have NMR/PET facility. I am looking some easily doable experiments.

I appreciate your suggestion.

Dear Mohammad, Histology may be helpful, take advice of Pathologist

First you should consider T1/2 of the apamine, this might be helpful in providing insight of duration of action. For the correlation between brain content and behavioral effect you can take out CSF/plasma samples at different time intervals after i.p. administratio and can estimate its content using HPLC-UV method (http://www.jas.org.pl/pdf/63.pdf). Further you can utilize this information to calculate T1/2 and minimum threshold level etc. 

I hope this would be helpful. 

Thank you Dr. Awanish. Idea is good but we want to see the tamapin at cell/tissue level in the brain. CSF would not able to answer our questions.

Radio isotope idea was great but we don't have NMR facility here.

By the way, thank you again for your comments.

Thank you Dr. Laveka. Yes, you are right. we have plan to go with biotinated tamapin injection and IHC but it will long time.

Thanks for your suggestions.

Shahid