Biochemical and morphological studies of the short and long term survival of isolated nerve-endings.

The respiratory rate, potassium, amino acid, ATP and phosphocreatine content of cortical synaptosomes were measured over periods from one hour to 5 days. Incubation medium or tissue culture medium at 37 degrees C was employed. In suspensions, synaptosomes show diminished levels of all these parameters after 3 or 4 h, but synaptosome beds showed no loss of potassium, ATP or phosphocreatine at this time. Morphologically the synaptosomes showed good preservation of structure during the first 24 h in tissue culture. Respiratory response to electrical pulses was detectable even after 24 h in culture when basal respiration was low.