Although most people usually focus on the brain cells when discussing brain preservation techniques, extracellular space is also worthy of consideration. In vivo, extracellular space makes up around 1/5th of overall brain volume, although this varies based on brain region, developmental stage, and surely many other factors. Over the past few months, Pallotto et al and Korogod et al both published articles relevant to the preservation and importance of the extracellular space.