Characteristics of slow and fast phases of the optocollic reflex (OCR) in head free pigeons (Columba livia): influence of flight behaviour
Version of Record online: 24 DEC 2001
© European Neuroscience Association
European Journal of Neuroscience
Volume 11, Issue 1, pages 155–166, January 1999
How to Cite
Gioanni, H. and Sansonetti, A. (1999), Characteristics of slow and fast phases of the optocollic reflex (OCR) in head free pigeons (Columba livia): influence of flight behaviour. European Journal of Neuroscience, 11: 155–166. doi: 10.1046/j.1460-9568.1999.00424.x
- Issue online: 24 DEC 2001
- Version of Record online: 24 DEC 2001
- Received 10 October 1997, revised 21 July 1998, accepted 5 August 1998
- head fast phases;
- head oscillations;
- optokinetic responses (OKR)
The effect of behavioural context on the properties of slow and fast phases of the horizontal optocollic reflex (OCR) were investigated in head free pigeons for two situations, i.e.: (i) animals were hung in a harness (‘resting condition’); (ii) animals were additionally submitted to a frontal airflow that provoked a flight posture (‘flying condition’) [Bilo & Bilo (1983) J. Comp. Physiol., 153, 111]. A ‘transient flight’ was also provoked in the ‘resting condition’ by tapping the breastbone region. Stimuli consisted either of velocity steps (30–300 °/s) or of an increasing velocity stimulus (0–300 °/s).
The amplitude of nystagmic beats and the OCR gain increased in the ‘flying condition’ and during ‘transient flight’ as compared to the ‘resting condition’. The OCR working range was considerably extended toward high velocities by the flying behaviour. In the ‘resting condition’, spontaneous head oscillations generally triggered a high-gain OCR, close to that obtained in the ‘flying condition’. One-third of the animals showed a higher gain in response to an increasing velocity stimulus than with step stimuli, in the high velocity range.
The linear relation between amplitude and peak velocity of OCR fast phases was independent of the stimulation velocity in the ‘resting condition’, whereas the amplitude and peak velocity increased with the stimulation velocity in the ‘flying condition’. In this condition, the fast phase velocity was correlated with the slow phase velocity, but not with the retinal slip velocity.
Thus, both the slow and fast phases of the OCR are dependent on the behavioural context.