Revision 1

Accepted · first revision · record

Title: Water exchange times across cell membranes in grey matter
Plain: Water moves in and out of brain cells while it is being measured, which blurs the distinction between inside and outside. Reported exchange times disagree by large factors.
Precise: Determine the mean intra-to-extracellular water exchange time $\tau_{ex}$ in human and rodent grey matter, which reported analyses place anywhere from about 10 ms to over 100 ms, using diffusion-time-dependent kurtosis, filter-exchange imaging or multi-dimensional relaxation-diffusion methods, while separating exchange from structural time dependence. An answer is a value with uncertainty that is consistent across methods.
Settled by: Agreement within 30 percent among independent exchange-sensitive methods on the same tissue, with a control of known permeability.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: contested
Status note: (empty)
Posed since: (empty)