RRC ID 4144
Author Gilland E, Baker R.
Title Evolutionary patterns of cranial nerve efferent nuclei in vertebrates.
Journal Brain Behav. Evol.
Abstract All vertebrates have a similar series of rhombomeric hindbrain segments within which cranial nerve efferent nuclei are distributed in a similar rostrocaudal sequence. The registration between these two morphological patterns is reviewed here to highlight the conserved vs. variable aspects of hindbrain organization contributing to diversification of efferent sub-nuclei. Recent studies of segmental origins and migrations of branchiomotor, visceromotor and octavolateral efferent neurons revealed more segmental similarities than differences among vertebrates. Nonetheless, discrete variations exist in the origins of trigeminal, abducens and glossopharyngeal efferent nuclei. Segmental variation of the abducens nucleus remains the sole example of efferent neuronal homeosis during vertebrate hindbrain evolution. Comparison of cranial efferent segmental variations with surrounding intrinsic neurons will distinguish evolutionary changes in segment identity from lesser transformations in expression of unique neuronal types. The diversification of motoneuronal subgroups serving new muscles and functions appears to occur primarily by elaboration within and migration from already established segmental efferent pools rather than by de novo specification in different segmental locations. Identifying subtle variations in segment-specific neuronal phenotypes requires studies of cranial efferent organization within highly diverse groups such as teleosts and mammals.
Volume 66(4)
Pages 234-54
Published 2005
DOI 10.1159/000088128
PII 88128
PMID 16254413
MeSH Animals Biological Evolution* Cranial Nerves / growth & development Cranial Nerves / physiology* Efferent Pathways / growth & development Efferent Pathways / physiology* Female Humans Neurons, Efferent / physiology Pregnancy Rhombencephalon / growth & development Rhombencephalon / physiology Vertebrates / physiology*
IF 1.542
Times Cited 37
Zebrafish NA