Comparative studies of fresh and postmortem isolated rat cortical synaptosomes: uptake and potassium-evoked release of gamma-aminobutyric acid.

Synaptosomal fractions were isolated from rat cerebral cortex immediately after decapitation and after 2 h and 4 h postmortem storage at room temperature. Uptake and release of [3H]GABA was compared between fresh and postmortem synaptosomal fractions. The results suggest that after a 2 h postmortem storage these functions are still comparable to those observed in fresh preparations, while a 4 h period of storage decreases them by about 50%. The present data are consistent with our previous findings that the 2 h postmortem fractions are comparable to freshly isolated fractions with respect to coupled respiration, potassium accumulation and capability of specific configurational changes.