Extended Data Fig. 5: The effect of advective flow on the time course of recovery of fluorescence after photobleaching.
From: Brain clearance is reduced during sleep and anesthesia
This was assessed in an in vitro experiment illustrated in a. A solution of 4 kDa FITC-dextran was passed through a gel (Methods) at a constant flow rate and the time course for the recovery of photobleaching recorded using an optical fiber, exactly as used in the experiments described in the text in vitro and in vivo. b, The observed half times were accurately predicted from equation [6] and reduced rapidly with increasing advective velocity. From the precision with which we could record changes in diffusion coefficients in vivo (Fig. 1d,e right panels) and their corresponding half times, we estimate that we would have been able to detect a change in advective flow of about 0.5 μm/s, or greater. Where error bars (SEM; n = 5 independent experiments) are not shown they were smaller than the size of the symbol.
