The reticular formation of the brainstem contains premotor systems for various musculomotor systems. In this paper, the bulbar premotor systems for jaw and tongue movements, head and neck movements, locomotion, and respiration and vocalization in birds are reviewed and compared to premotor systems in mammals. Roughly, the bulbar reticular formation can be subdivided in three longitudinal zones: a dorsolateral (RPcdl) and a ventromedial (RPcvm) parvocellular zone and a gigantocellular zone (RGc). RPcdl contains premotor neurons for the jaw and neck system, RPcvm for the @entity89 , and RGc for the @entity5773 . RPcdl receives input from the descending sensory trigeminal system, parts of RPcvm and RGc from vestibular nuclei, whereas the tectum has a projection to the contralateral RGc. RPcdl and RPcvm receive substantial telencephalic input through the occipitomesencephalic tract. The bulbar part of the respiratory system consists of a series of cell groups in the ventrolateral reticular formation and has connections with motor centers of the vocalization system. The similarities and differences between the avian and @entity1 situation are discussed. Musculomotor systems participate in various activities. It is argued that a premotor system should possess sufficient @entity8364 to control the participation of a motor system in the different activities. This @entity8364 may permit the occurrence of learning processes in terms of refining basically existing motor patterns. The emergence of new and more complex motor patterns as in vocalization requires the involvement of hierarchically higher brain centers.

The neural substrate for 'learned' and 'nonlearned' activities in birds: a discussion of the organization of bulbar reticular premotor systems with side-lights on the XXXX situation.

@entity1 :: ('9606', 'Species') :: ['mammalian'] @entity5773 :: ('MESH:D014060', 'Disease') :: ['tongue and locomotory system'] @entity89 :: ('MESH:D007571', 'Disease') :: ['jaw, tongue and neck system'] @entity8364 :: ('MESH:D002375', 'Disease') :: ['flexibility']
@entity1 :: (9606,Species) :: ['mammalian']
