[Neurosecretory activity during regeneration in the oligochaete annelid Tubifex tubifex].

Abstract

Following amputation of the posterior half of Tubifex, all the nerve cells stainable by paraldehyde fuchsin (NF) immediately discharged. Fifteen minutes later, some stained NFs reappeared. Their number increased, reached a peak far above the normal level, then slowly decreased. This peak occurred 8 hours after amputation in the brain, after 3-4 days in the ventral ganglia. A similar cycle took place during the anterior regeneration of Tubifex whose four anterior segments were previously cut away. Following a double amputation (behind the first or fourth segment and at half length), the stimulation of the neurosecretory activity was even clearer, the number of NFs reaching a higher and earlier peak. Correlatively, the regenerative histogenesis was accelerated in the caudal blastema.