B. Schreiber

Risposte differenziali del piccione viaggiatore e normale alla sollecitazione rotatoria

Summary The : variations in the electric activity of the cerebellum during and after rotation of the animals have been recorded in domestic and homing pigeons, as well as stationary and migratory turtle doves. Various types of electrodes were used: 1) external, 2) inserted into the sides of the vermen, 3) bifilar microelectrodes and 4) concentrical electrodes laid on the vermen. Electrical recordings were effected simultaneously with those of the tangential and centripetal acceleration forces determined by the rotation. In all cases a rimareable increase in the amplitude of the cerebellar potential during the action of tangential and centripetal acceleration was noted. A higly characteristic reaction in the form of rhylmical prolonged « after discharges » was found to be present whit homing pigeons and migratory turtle doves, while it was absent in domestic pigeons and stationary doves.

Sulla percentuale di comparsa di una reazione cerebellare propria del piccione viaggiatore in altre razze domestiche e semidomestiche di piceioni

Summary Homing pigeons alwais show, after an appropriate rotatory stimulation, a peculiar electric activity of cerebellar origin represented by prolonged rhytmic after discharges. In non orienting domestie races the after discharges are found in same individuals with frequencies that range from 10% in rock-pigeons of the squares to 40% in one peculiar italian race (Piacentini). The appearance of after discharges in non homing pigeons may be the result of hybridation with homing pigeons, or the persistence of the ancestral trait.