Comparison of rat brain membrane antigens by complement mediated release of neurotransmitters from brain fractions...

Synaptosomal, glial and neuronal fractions were prepared from rat brain and incubated to accumulate radioactively labelled neurotransmitters. Treatment of these fractions with antisera and complement showed that anti-(Thy-1) serum gave good release (50-75% of total uptake) of all neurotransmitters tested from synaptosomal and glial fractions. GABA and glutamate were released from neuronal perikarya, but not norepinephrine or serotonin. Anti-(S-100) serum gave no significant release of any neurotransmitter tested from any of the fractions, although all of them had previously been shown to contain this protein. These results are compatible with the membrane nature of Thy-1 and the mainly soluble nature of S-100 protein. They permit a selection for membrane antigens and neurotransmitters from different brain fractions. Antigenic differences between neuronal and glial plasma membranes were suggested by results with antiserum raised against bulk-isolated rat neuronal perikarya.