B. Best was one of the initiators of the Hippocampal Slice Cryopreservation Project (HSCP). For work at this project, Dr. Yuri Pichugin was specially invited from Ukraine. The aim of the project was vitrification (cooling accompanied with liquid vitrescence without formation of ice crystals) of hippocampal slice obtained from the rat brain. That hippocampal slice was firstly frozen to −130 С, then it was heated up and tested for vitality. Though great attention is now given to cryopreservation of immature neurons for the needs of following therapeutic intracerebral transplantation, there is no scientific publications devoted to cryopreservation of mature arranged brain tissues which have potential interest for pharmaceutical industry. Y. Pichugin’s group has reported about first experiments in cryopreservation of cross sections of mature rats’ hippocamps. Microscopic examination has shown serious damages in frozen thawed slices; however, the state of their ultrastructural and histological preservation was evaluated as good and perfect. Research results have firstly shown that complicated neuronal networks can be well preserved by vitrification. Moreover, vitrification mixture, that has appropriate K/Na ratio and causes minimal damages, was developed. Those results can help in psychoneurological drug development and transplantation of complex brain areas for cure of brain diseases and injuries.