Figure 2: Comparison between the fluorescence emissions in brain cross-sections (about 15 slices) obtained after 24 hours following 1, 2 and 3 administrations of intranasal FITC-insulin in aqueous solution or microemulsion to rats (n=11). A comparison was also made with the corresponding systemic IV administrations of FITCinsulin solution (n=3). All photographs were taken at the same magnification and light conditions. Also are shown the averaged fluorescence levels as processed by MATLAB software. Significant difference between intranasal microemulsion and both nasal aqueous solution and intravenous injections is denoted as **, and between intranasal microemulsion and nasal aqueous solution only is denoted as * (see also Table 1).