title: Long-term storage of functional, isolated nerve endings by slow freezing and rapid thawing.
abstract: Nerve endings (synaptosomes) were isolated from homogenized rat brain corpora striata following centrifugation on discontinuous sucrose gradients. The synaptosomes (in 0.8 M sucrose) were (i) slowly frozen by placing the tube containing the suspension in a freezer at -10 degrees C for 1 h followed by (ii) swirling in a mixture of acetone and dry ice for 15 min and (iii) were stored in liquid nitrogen for up to 6 weeks. Freshly isolated synaptosomes and synaptosomes from the same preparation that were frozen for 2, 4, or 6 weeks and rapidly thawed in a water bath at 37 degrees C were re-equilibrated with a physiological salt solution and assayed for their ability to accumulate Ca and to release transmitter (dopamine) upon depolarization in high K medium. K-dependent Ca uptake gradually declined to approximately 1/3 the value observed with freshly isolated synaptosomes after 6 weeks of storage. K-stimulated dopamine release (only from intact synaptosomes) was normal over the entire period of storage. It is concluded that synaptosomes retain their physiological properties when stored frozen for a few weeks and that cold storage may be a useful technique for experiments requiring lengthy or repeated assays or accumulation of material.
authors.affiliation: Department of Physiology, University of Maryland School of Medicine, Baltimore 20201.
authors.forename: P
authors.initials: P
authors.lastname: Drapeau
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D005615:Freezing; D066298:In Vitro Techniques; D009411:Nerve Endings / Q000378:metabolism; D011309:Preservation, Biological / Q000379:methods*; D013574:Synaptosomes / Q000378:metabolism; D013997:Time Factors
chemical_list: D002118:Calcium; D004298:Dopamine