ISOLATION OF SYNAPTIC COMPLEXES IN A CAESIUM CHLORIDE DENSITY GRADIENT - ELECTRON MICROSCOPIC AND IMMUNOHISTOCHEMICAL STUDIES

A technique is described for the improved isolation of synaptic complexes. Homogenates of guinea pig cerebellum and cerebral cortex were subjected to centrifugation, first in a discontinuous sucrose gradient, and secondly in a continuous caesium chloride gradient. Of the six bands that were obtained, band four contained a high proportion of synaptic complexes showing both pre‐ and postsynaptic elements attached to each other; myelin and free mitochondria were not contaminants of this fraction. Fluorescein‐labelled γ‐globulin prepared against band four reacted with synaptic regions of cerebellum and cerebral cortex, but not with cervical cord. Copyright © 1969, Wiley Blackwell. All rights reserved