The purpose of this protocol is to compare the intake and clerance kinatics of JF dye systemic delivery using retro orbital injections.We image a mouse with a crenial window before and after systemic dye injection.We want to fit the clearance of the dye with a double exponanatial decay function:y = \textbf a*e^{-\frac{1}{\textbf b*x}}+\textbf c*e^{-\frac{1}{\textbf d*x}} + \textbf e