Ephrin-A5 promotes the formation of terminal thalamocortical arbors.
Ephrins-A5 are expressed in the cortical target layer of thalamic afferents at the time when these axons form terminal arbors. Previous in-vitro studies provided evidence that ephrin-A5 supports the branching of thalamic axons, but there is no direct in-vivo evidence for such a growth-promoting effect. Here we examined thalamocortical projections in ephrins-A5 deficient mice. Our results demonstrate that the laminar specificity of thalamic afferents in ephrin-A5 mutants remains preserved, but axonal arbor formation is greatly reduced. Thus, ephrin-A5 specifically regulates branch formation of thalamic axons, but does not affect target layer selection. Ephrin-A5-mutant mice are, therefore, a unique model to study the effects of reduced thalamic innervation on the assembly of cortical circuits and sensory processing.
Uziel
Daniela
D
University of Jena, Institute for General Zoology, Erberstrasse 1, Jena, Germany.
Mühlfriedel
Sven
S
Bolz
Jürgen
J
D000344:Afferent Pathways; D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000502:physiology; D048430:Cell Shape; D002540:Cerebral Cortex / Q000166:cytology* / Q000196:embryology* / Q000502:physiology; D036386:Ephrin-A5 / Q000235:genetics / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009924:Organ Culture Techniques; D011247:Pregnancy; D013788:Thalamus / Q000166:cytology* / Q000196:embryology* / Q000502:physiology
D036386:Ephrin-A5