Role of the vestibular commissure in gaze-holding in the cat

Nitric oxide facilitates GABAergic neurotransmission in the cat oculomotor system: a physiological mechanism in eye movement control

“…However, the results obtained following pharmacological modification of the inhibitory neurotransmission systems reveal a large variability, which makes it difficult to understand comprehensively how neurotransmitters work in the generation of velocity and position signals in the PH nucleus. Thus, strychnine, which in our experiments caused velocity imbalance, has been reported to produce either velocity imbalance, gaze‐holding deficit, or no effect on eye movements (Mettens et al 1994 b ; Arnold et al 1999). Furthermore, Arnold et al (1999) have shown that bicuculline produced gaze‐holding deficits when administered in the PH nucleus of monkeys, whereas in the present study, similar doses did not produce signs of eye position alteration in the cat, except for an increase in phase lead when VOR was induced at 0.1 Hz.…”

“…Drug injections in the PH nucleus produced nystagmus with either straight or curved slow phases separated by quick resetting movements. The significance of these two types of eye movement alteration has been well established (Cannon & Robinson, 1987; Godaux et al 1993; Mettens et al 1994 a, b, c ; Godaux & Cheron, 1996; Moreno‐López et al 1998). Velocity imbalance, such as that produced when the tonic inputs from both vestibular nuclei are not identical, produces nystagmus with straight slow phases.…”