[Electromyographic studies of the musculus rectus nasalis in postnatal growing rabbits while turning the animal on...

In rabbits aged 1-15 days and in a comparative group of adult animals, the EMG of the musculus rectus nasalis was recorded during a turn after speed jumps from 0 degrees/sec to 30 degrees/sec, 60 degrees/sec and 144 degrees/sec, respectively, through a path of 360 degrees. From the first day of life, an electrical activity consistent with the rapid and slow phase of the nystagmus was found. The EMG potentials, the so-called bursts, underwent qualitative changes with age that can be taken to reflect increasing maturation both of centralnervous mechanisms of inhibition and a functional transformation of the eye-muscles. The number of bursts increased with age during the turn; the latency period from the onset of turning to the appearance of the bursts was reduced. The differences observed at the three turning speeds are discussed with regard to the age of the animals.