Theoretical local freezing times of small rodent brains submerged in situ in liquid nitrogen

Abstract

In situ freezing is a standard procedure, typically applied in neuroscience, to stop post-mortem metabolism and diffusion. However, the concentration of a compound under study may well change before the tissue is completely frozen. Knowing the approximate local freezing time should make it possible to control this problem. A mathematical model of in situ freezing in liquid nitrogen has recently been introduced, and freezing times derived from this model are presented here. The hope is that this information will be considered useful when in situ freezing of small rodent brains is applied.