SENSORIMOTOR ASPECTS OF FLIGHT CONTROL IN BIRDS - SPECIALIZATIONS IN THE SPINAL-CORD

Avian bipedal locomotion and flight suggest specializations in sensori motor integration as compared to quadrupedal vertebrates. Specializati ons at the level of the spinal cord were studied with neuroanatomical tracing experiments in pigeons. Bird-specific connections were found i n the exteroreceptive system (receptors associated with feathers) and in the proprioreceptive system (spinocerebellar pathways). These speci alizations seem to be related to flight control. Neurons of the margin al nuclei (accessory lobes) in the lumbosacral cord, which are unique to birds, have propriospinal connections mainly to the contralateral v entral cord. The functional role of these nuclei remains enigmatic.