Die Lage- und Bewegungsreflexe der Vögel

Abstract

Frfihere Untersuchungen 1 hatten gezeigt, daG am Zustandekommen der kompensatorischen Halss~ellung und an ihrer StSrung nach Labyrinthentfernung die yon den Cristae ausgehenden Erregungen beteiligt sein mfissen. Da diese Befunde der Auffassung der Magnusschen Schule 2 widersprechen, babe ich die Frage untersucht, ob bei den /raglichen Erseheinungen die Maculae i~berhaupt eine RolIe spielen und wit im Experiment die E//elcte der Cristae und Maculae voneinander trennen ~6nnen. I. Versuchanordnung und Beschreibung der Be/uncle. Als Methode wiihlte ich die zweizeitige Labyrinthoperation. Es wurde zunachst ~uf einer Seite operiert (Operation I), bis zum Eintritt der Degeneration im ZI~S. gewartet und dann die Operation am anderen Labyrinth angesehlossen (Operation II). Die Operationen waren entweder auf beidenSeiten gleich oder ungleich und bestanden in der Wegnahme der Bogeng~nge, der Bogengi~nge mit Ampullen oder des ganzen Labyrinths in allen Kombinationen. Durch die getroffene Anordnung war es mSglich, einmal festzustellen, ob und wieweit die dutch die erste Operation eingetretenen Stgrungen dutch die zweite verdindert werden, zweitens zu ermitteln, ob zwischen den E//e]cten ein-und zweizeitig vorgenom~ener doppelseitiger Eingri//e Unterschiede bestehen.

Pigeons (C. livia) Follow Their Head during Turning Flight: Head Stabilization Underlies the Visual Control of Flight

“…Similarly, reflexes related to cervical and vestibular systems in normal and labyrinthectomized hand-held pigeons led to comparing the flight control system of birds to the autopilot of an airplane. From such studies, Groebbels ( 1926 , 1929 ) proposed that birds control body motion by tracking head motion, essentially “following their turning heads.” In support of this hypothesis, certain wing and tail muscles in the pigeon react to vestibular stimulation, angular visual stimulation, and passive or active lateral head deflections when under simulated flight conditions (Bilo and Bilo, 1978 , 1983 ). Observations of maneuvering pigeons, zebra finches, and lovebirds provide further evidence that head stabilization likely plays a role in flight control (Bilo et al, 1985 ; Davies and Green, 1988 ; Warrick et al, 2002 ; Eckmeier et al, 2008 ; Kress et al, 2015 ).…”

The Labyrinthine and Postural Mechanisms.

“…From Bechterew's results we should then have to conclude also that the slow phase cannot be of vestibular origin. So far as I can see, the conclusion to be drawn from his results should be that in that type of nystagmus both phases, the quick and the slow, are of central origin, produced by unbalanced activities of the central neural mechanisms, just as is any nystagmus which is elicited by some means in an animal which is bilaterally labyrinthectomized [lesion of the vestibular nuclei in the brain-stem (Spiegel and Sato, 1926) or galvanization of the head (Groebbels, 1922)]. The main objection to Maupetit's thesis is the fact that on habitual rotation the quick phase disappears gradually, whereas the slow phase, expressing itself then as a slow deviation, remains (Dodge,192U).…”

“…Breuer (1874) showed that this is true also if visual stimuli are excluded. Later observations were made by Trendelenburg (1906a, 19064), Trendelenburg and Kiihn (1908), Huxley (1913), andGroebbels (1922).…”

Vestibular sensations and the mechanisms of balance.

“…Davis and Pollock (11) have used the method of decerebration to study the tone of neck and limb muscles under various types of intra-oral destruction of the labyrinth on one and on both sides. Groebbels (40), in particular, has made elaborate studies of posture and tonus in pigeons under various types of labyrinthine stimulation. He has succeeded in gaining objective measures of changes in tonus and has described these changes as they stand related to each of the three ampullae.…”