Ephrin-B3-EphA4 interactions regulate the growth of specific thalamocortical axon populations in vitro.
The role was studied of ephrin-B3, a ligand of the Eph family of tyrosine kinase receptors, in the formation of cortical connectivity. In situ hybridization and immunohistochemistry showed that EphA4, a receptor of ephrin-B3, was expressed in the lateral thalamus (visual and somaotosensory thalamus) of the developing rat brain, but not in the medial thalamic nuclei which project to the limbic cortex. Correspondingly, ephrin-B3 was expressed strongly in the developing limbic cortex including amygdala, entorhinal cortex and hippocampus. To examine the action of ephrin-B3 on thalamic axons, either lateral or medial thalamic explants were cultured on membranes obtained from ephrin-B3-expressing COS cells. Axonal growth was inhibited for cells from the lateral thalamus but not from the medial thalamus. These results suggest that ephrin-B3 contributes to regional specificity by suppressing axonal growth of lateral thalamic neurons.
Takemoto
Makoto
M
Neuroscience Laboratories, Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Fukuda
Tsuyoshi
T
Sonoda
Rie
R
Murakami
Fujio
F
Tanaka
Hideaki
H
Yamamoto
Nobuhiko
N
D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000648:ultrastructure; D019556:COS Cells; D002450:Cell Communication / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D018920:Coculture Techniques; D036389:Ephrin-B3 / Q000235:genetics*; D005333:Fetus; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D009434:Neural Pathways / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D009924:Organ Culture Techniques; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D036122:Receptor, EphA4 / Q000235:genetics*; D013788:Thalamus / Q000166:cytology / Q000196:embryology / Q000378:metabolism*
D036389:Ephrin-B3; D012333:RNA, Messenger; D036122:Receptor, EphA4