Nerves and taste-buds degeneration in the cat-fish Ictalurus melas.

After nerve transection, external taste-buds remain apparently normal for more than 3 weeks, become round, then disappear. Cryonecrosis of the cranial ganglia V and VII induces a loss of polarity of the buds, which, though keeping up their form for 50 and even 150 days, are progressively deprived of sensory cells. This shows a dissociation of the actions of nerve factors.