Figure 2-S3

Figure 2-S3

(a) Time plot showing LPS level changes in different regions as a ratio of injected fluorescent LPS. Injected LPS level was determined by the relative saturation level of fluorescence in the hindbrain ventricle as it is the immediate site filled in by LPS at time of injection. Both hindbrain and telencephalon ventricles reach 100% maximum LPS level based on fluorescence, while hindbrain interstitial space reaches around 30% of maximum and the periphery based on accumulation in the pronephros as a proxy reaches less than 15% of maximum. This plot illustrates a small fraction of maximum LPS that does get passed onto the periphery. Plot shows average and s.e.m. (standard error of means) of data from three independent LPS-injected animals. See Figure 2 for related analysis of tracing LPS from brain microinjection. (b) Still images of key events from tracing LPS-Alexa 594 after brain injection by high-resolution time-lapse stereomicroscopy, taken from a different LPS-injected animal than the example shown in Figure 2. Injection occurred at the 4s timepoint. Some injected animals such as this one, LPS is detected to also move anteriorly from midbrain/hindbrain ventricle into telencephalon ventricle. By 48 min post injection, we detected broad distribution of LPS in circulation at a low intensity. FL, facial lymphatics; blec, brain lymphatic endothelial cells; hbv, hindbrain ventricle; mb, midbrain; hb, hindbrain; tele, telencephalon; m, minute; s, second.