Morphological maturation and survival of chicken and rat embryonic neurons on different culture substrata.

Neuronal cells from chicken and rat embryonic cerebral hemispheres were plated at a low cell concentration and cultured either on collagen or on a supporting continuous glial layer for periods of up to 21 days. The glial layer was either homologous or heterologous with regard to the animal species; the survival and maturation of the neuronal cells in these different conditions were investigated by light and electron microscopy. Neuronal cells cultured on collagen formed aggregates similar to those formed by neuronal cells plated at high cell density as described in a previous paper; a few aggregated neurons formed processes after 24 h and, only after 48 h of culture, more fibres had developed; the majority of the cells progressively degenerated between days 7 and 21 of culture.

Chemically defined medium for rat astroglial cells in primary culture.

We have developed a serum-free defined medium that supports the growth in primary culture of rat astroglial cells. Cells dissociated from cerebral hemispheres of newborn rats were maintained for 4 days in a basal medium (Waymouth's medium) containing 10% fetal calf serum, which was substituted by a serum-free medium. The basal medium was supplemented with insulin (5 μg/ml) and fatty acid free bovine serum albumin (0.

Influence of brain extract and dibutyryl cyclic AMP on the amount of carbonic anhydrase in primary glial cell cultures from newborn rat brain.

The effect of brain extracts from rat and beef, and of 2',5'-dibutyryl cyclic AMP on the CAII content was investigated in rat primary glial cultures maintained in serum-containing or serum-free medium. All cultures contained a mixed population of oligodendroglial and astroglial cells, but under certain conditions the cultures were highly enriched in oligodendroglial cells. An immunocytochemical positive reaction to CAII was observed in oligodendrocytes, while astrocytes were not stained.

Amino acid and carbohydrate compositions of human serum dopamine-β-hydroxylase.

Dopamine-β-hydroxylase has been purified from human serum. The amino acid composition has been determined and found to be similar to that of the enzyme purified from human pheochromocytoma. Human serum dopamine-β-hydroxylase is a glycoprotein, containing 13.

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We have shown the existence in rat liver of free light cytoplasmic particles containing a stable, rapidly labelled RNA. These particles differ from the 45 S ribosomal fraction by several characters.The buoyant density and sedimentation properties suggest that these particles are similar to dRNA ribonucleoprotein particles released from polysomes and to those present in rat liver nuclei.