Dopamine and serotonin in two populations of synaptosomes isolated by percoll gradient centrifugation.
A technique has recently been developed for the isolation of synaptosomes by centrifugation through percoll gradients. Utilizing this procedure, striatal synaptosomes were separated into two fractions, termed fractions 3 and 4, by their different sedimentation characteristics in percoll. The aim of this investigation was to determine whether there were any neurotransmitter differences between these fractions. The content of endogenous neurotransmitters dopamine (DA) and serotonin (5-HT) significantly differed between these fractions. Fraction 3 contained greater levels of 5-HT, while fraction 4 was enriched for DA. Both fractions were capable of releasing DA or 5-HT upon K(+) depolarization. The results raise the possibility that a relative enrichment of dopaminergic synaptosomes in fraction 4 and of serotonergic synaptosomes in fraction 3 has been achieved.
Robinson
P J
PJ
Merrell Dow Research Institute, 2110 E. Galbraith Road, Cincinnati, OH 45215, U.S.A.
Lovenberg
W
W