LONG-TERM SURVIVAL OF CORTICAL-NEURONS FROM ADULT GUINEA-PIG MAINTAINED IN LOW-DENSITY CULTURES

IN vitro survival of neurones isolated from adult mammalian brain is n ormally scarce and the postnatal age limit for obtaining viable cultur es of cortical, hippocampal and diencephalic neurones is commonly two weeks. Here we describe a novel procedure for the establishment and lo ng-term maintenance of cortical neurones of the adult mammalian brain in low-density cultures. Neurones isolated from the piriform cortex of 30- to 90-day-old guinea-pigs were initially grown in a chemically de fined medium enriched with basic fibroblast growth factor (bFGF); late r, a small quantity of foetal bovine serum (FBS) was added to facilita te cell differentiation. Under these conditions cells could be maintai ned in culture for at least 3 weeks, when indirect immunocytochemistry and whole-cell patch-clamp recordings were performed. Cells exhibitin g neuronal morphology expressed the neuronal marker microtubule associ ated protein-2 (MAP2) and generated action potentials. Moreover, about 70% of the MAP2-immunoreactive cells were simultaneously labelled wit h anti-gamma-aminobutyric acid (GABA) antibody. Cells expressing neuro nal antigens were never labelled by antibody raised against the glial marker glial fibrillary acidic protein (GFAP). These results indicate that long-term survival of adult neurones can be achieved under defini te culture conditions.