Functional characteristics of nerve endings isolated from the brain by Hajos' method

Abstract

A study was made of the functional potentialities of synaptosomes isolated from the brain cortex and lumbar enlargement of the spinal cord. The yield of synaptosomes from the brain cortex amounted to 10 mg (with reference to protein) from 1 g of wet tissue, and that of synaptosomes from the spinal cord was equal to 1/3 of the yield from the brain, with the preparation being strongly contaminated with myelin scraps. Brain synaptosomes were marked by high level of respiration whose magnitude was affected by the agents (ouabain, high concentrations of K+ and benzylpenicillin) that change ion membrane transport. Synaptosomes maintained higher GABA gradient across the plasmatic membrane. Ouabain and potassium depolarization produced a considerable release of GABA and 3H-GABA into the incubation medium. A conclusion is made that the method of Hajos should be rather used for rapid isolation of the synaptosomal fraction from the rat brain cortex.