Induction of ephrin-B1 and EphB receptors during denervation-induced plasticity in the adult mouse hippocampus.
Abstract It has been widely demonstrated that Eph receptors and their ephrin ligands play multiple pivotal roles in the development of the nervous system. However, less is known about their roles in the adult brain. Here we reported the expression of ephrin-B1 and its cognate EphB receptors in the adult mouse hippocampus at 3, 7, 15, 30 and 60 days after transections of the entorhinal afferents. In situ hybridization and immunohistochemistry showed the time-dependent up-regulation of ephrin-B1 in the denervated areas of the hippocampus, which initiated at 3 days postlesion (dpl), reached maximal levels at 7-15 dpl, remained slightly elevated at 30 dpl and recovered to normal levels by 60 dpl. Double labeling of ephrin-B1 and glial fibrillary acidic protein revealed that ephrin-B1-expressing cells in the denervated areas were reactive astrocytes. Furthermore, a ligand-binding assay using ephrin-B1/Fc chimera protein also displayed the up-regulation of EphB receptors in the denervated areas of the hippocampus in a similar manner to that of ephrin-B1. Within the first week postlesion, the EphB receptors were expressed by reactive astrocytes. After 7 dpl, however, EphB receptors were expressed not only by reactive astrocytes but also first by sprouting axons and later by regrowing dendrites. These results suggest that the ephrin-B1/EphB system may participate in the lesion-induced plasticity processes in the adult mouse hippocampus.
Wang
Yan
Y
Key Laboratory of Neurobiology, Shanghai Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, PR China.
Ying
Guo-Xin
GX
Liu
Xin
X
Wang
Wen-Yuan
WY
Dong
Jing-Hui
JH
Ni
Zi-Mei
ZM
Zhou
Chang-Fu
CF
D000367:Age Factors; D000818:Animals; D001253:Astrocytes / Q000502:physiology; D003714:Denervation; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology; D036387:Ephrin-B1 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D009473:Neuronal Plasticity / Q000502:physiology*; D036225:Receptor, EphB1 / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology
D036387:Ephrin-B1; D036225:Receptor, EphB1