title: Remodeling the Dendritic Spines in the Hindlimb Representation of the Sensory Cortex after Spinal Cord Hemisection in Mice.
abstract: Spinal cord injury (SCI) can induce remodeling of multiple levels of the cerebral cortex system especially in the sensory cortex. The aim of this study was to assess, in vivo and bilaterally, the remodeling of dendritic spines in the hindlimb representation of the sensory cortex after spinal cord hemisection. Thy1-YFP transgenic mice were randomly divided into the control group and the SCI group, and the spinal vertebral plates (T11-T12) of all mice were excised. Next, the left hemisphere of the spinal cord (T12) was hemisected in the SCI group. The hindlimb representations of the sensory cortex in both groups were imaged bilaterally on the day before (0d), and three days (3d), two weeks (2w), and one month (1m) after the SCI. The rates of stable, newly formed, and eliminated spines were calculated by comparing images of individual dendritic spine in the same areas at different time points. In comparison to the control group, the rate of newly formed spines in the contralateral sensory cortex of the SCI group increased at three days and two weeks after injury. The rates of eliminated spines in the bilateral sensory cortices increased and the rate of stable spines in the bilateral cortices declined at two weeks and one month. From three days to two weeks, the stable rates of bilaterally stable spines in the SCI group decreased. In comparison to the control group and contralateral cortex in the SCI group, the re-emerging rate of eliminated spines in ipsilateral cortex of the SCI group decreased significantly. The stable rates of newly formed spines in bilateral cortices of the SCI group decreased from two weeks to one month. We found that the remodeling in the hindlimb representation of the sensory cortex after spinal cord hemisection occurred bilaterally. This remodeling included eliminating spines and forming new spines, as well as changing the reorganized regions of the brain cortex after the SCI over time. Soon after the SCI, the cortex was remodeled by increasing spine formation in the contralateral cortex. Then it was remodeled prominently by eliminating spines of bilateral cortices. Spinal cord hemisection also caused traditional stable spines to become unstable and led the eliminated spines even more hard to recur especially in the ipsilateral cortex of the SCI group. In addition, it also made the new formed spines unstable.
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Kexue
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, People's Republic of China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.affiliation: Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Licheng
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Physiology and Neuroscience, New York University School of Medicine, New York, New York, 10016, United States of America.
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Gan
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Lihai
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, People's Republic of China.
authors.forename: Peifu
authors.initials: P
authors.lastname: Tang
mesh_terms: D000344:Afferent Pathways / Q000473:pathology; D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D002818:Cordotomy / Q000379:methods; D049229:Dendritic Spines / Q000473:pathology*; D004195:Disease Models, Animal; D004292:Dominance, Cerebral; D017930:Genes, Reporter; D006614:Hindlimb / Q000294:innervation*; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009473:Neuronal Plasticity / Q000502:physiology*; D011184:Postoperative Period; D066191:Sensorimotor Cortex / Q000473:pathology*; D013119:Spinal Cord Injuries / Q000473:pathology*; D014945:Wound Healing
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria