Synaptosomes plasma membranes prepared from

The protein yield of the synaptosomal plasma membrane preparation is interpolated from a plot of absorbance at 595 nm against protein concentration for the BSA standards. 

Decapitation without using anesthetics is preferable, because anesthetics may affect the biological properties of the synaptosomal plasma membrane preparation The brain should be dissected on ice immediately after decapitation. Brains from species other than rat can also be used to prepare synaptosomal plasma membranes using this protocol... 

For further dissection, prepare a chilled dissection surface by placing a circular Whatman filter paper, soaked with isotonic sucrose solution, on top of an inverted, ice-filled Petn dish (see Note 3). Dissect the brain, as required, on this ice-cold surface (e g., if preparing synaptosomal plasma membranes from forebrain only, set the brain on the filter paper and remove the brainstem and cerebellum). 

A similar mechanism of binding and cotranslocation of 5-HT", Na and Cl was demonstrated by using plasma membrane vesicles prepared from a synaptosomal fraction of mouse cerebral cortex [18,19]. The stoichiometry of transport in this case however was 5-HT Na Cr=l 2 l. 

Preparation of sub-synaptosomal fractions showed that after labelling vivo, phosphatidate of Fraction E which contains marker enzymes for endoplasmic reticulum and plasma membrane (but not in higher concentration than some other fractions) had the highest specific radioactivity (Table 1). The most active phosphatidylinositol was in the synaptic vesicle fraction. Electrical stimulation provoked loss of these particular pools of phospholipid, while there was little effect on either phospholipid in the remaining fractions, as can be seen from the Table. 

Recently, a specific antibody against the purified cytosolic sialidase from rat skeletal muscle was prepared and its immunoreactivity with other sialidases examined (Miyagi et al., 1990b). The antibody completely immunoprecipitates the cytosolic enzyme in rat liver and skeletal muscle, but not the synaptosomal and lysosomal enzymes in rat brain and liver. These results suggest that a single cytosolic sialidase species may exist in rat tissues which is immunologically distinct from the lysosomal and plasma membrane enzymes. 

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