[Radioautographic study of the in vitro incorporation of tritiated noradrenaline into central catecholaminergic fibers in active and hibernating hedgehogs].

After in vitro incubation for 15 min at 38 degrees C with tritiated noradrenaline (3H-NA) of pieces of brain, including cortex and hypothalamus, from active hedgehogs, significant radioautographic reactions were observed on thick and thin sections where they overlaid catecholaminergic varicosities. Such reactions were severely decreased in the same in vitro conditions using brains from hibernating animals. After reserpine treatment they disappeared in active animals and could not be observed during hibernation. There were no reactions in these two cases following incubation at 6 degrees C. Incorporation of 3H NA at 6 degrees C in central catecholaminergic fibers does not there fore differ in homeotherms and in this hibernating animal. Its reduction during hibernation, even after (rapid) warming up at 38 degrees C, might be related to the impairment of energetic metabolic processes during this period.