[Decrease of the slow phase velocities of postrotatory nystagmi as a result of the otolith organs stimulation].
Intact pigeons were rotated in darkness in a horizontal plane at various orientations relative to axis of rotation, which passed between labyrinths, or was displaced relative to them. Trapezoidal (tests 1) and triangular (tests 2) rotation programs were used. In the tests 1, positive and negative angular accelerations were separated by two-minute periods of rotation with constant angular velocity. Such periods were absent in the tests 2. Results of the canal-otolith interactions in the tests 1 and 2 were different only in postrotatory nystagmi: the peak velocities of the slow phases decreased in both postrotatory nystagmi in the tests 1, but only in one of them in the tests 2. Apparently, at oppositely directed postrotatory nystagmi, decrease of peak velocities in the tests 1 is provided with different mechanisms. At one of them the decrease of nystagmus velocity reflects a result of a summation of canal and otolithic signals on the interneurones of the semicircular canal reflex arches, whereas at another one it is related with long-lasting activity imbalance of these interneurones which is supported by otolithic afferentation during rotation at constant angular velocity.
Stolbkov
Iu K
IuK
Orlov
I V
IV
D000818:Animals; D010856:Columbidae / Q000502:physiology*; D009760:Nystagmus, Physiologic; D010037:Otolithic Membrane / Q000502:physiology*; D012399:Rotation / Q000009:adverse effects*