title: Mechanism of Forelimb Motor Function Restoration after Cervical Spinal Cord Hemisection in Rats: A Comparison of Juveniles and Adults.
abstract: The aim of this study was to investigate forelimb motor function after cervical spinal cord injury in juvenile and adult rats. Both rats received a left segmental hemisection of the spinal cord after C3-C4 laminectomy. Behavioral evaluation of motor function was monitored and assessed using the New Rating Scale (NRS) and Forelimb Locomotor Scale (FLS) and by measuring the range of motion (ROM) of both the elbow and wrist. Complete left forelimb motor paralysis was observed in both rats. The NRS showed motor function recovery restored to 50.2 ± 24.7% in juvenile rats and 34.0 ± 19.8% in adult rats. FLS was 60.4 ± 26.8% in juvenile rats and 46.5 ± 26.9% in adult rats. ROM of the elbow and wrist were 88.9 ± 20.6% and 44.4 ± 24.1% in juvenile rats and 70.0 ± 29.2% and 40.0 ± 21.1% in adult rats. Thus, the NRS and ROM of the elbow showed a significant difference between age groups. These results indicate that left hemisection of the cervical spinal cord was not related to right-sided motor functions. Moreover, while motor paralysis of the left forelimb gradually recovered in both groups, the improvement was greater in juvenile rats.
authors.affiliation: Department of Orthopaedic Surgery, Kyorin University, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-0004, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hasegawa
authors.affiliation: Department of Orthopaedic Surgery, Kyorin University, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-0004, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Orthopaedic Surgery, Kugayama Hospital, 2-14-20 Kitakarasuyama, Setagaya-ku, Tokyo 157-0061, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Satomi
authors.affiliation: Department of Orthopaedic Surgery, Kyorin University, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-0004, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ohne
authors.affiliation: Department of Orthopaedic Surgery, Kyorin University, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-0004, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Takeuchi
authors.affiliation: Department of Orthopaedic Surgery, Kyorin University, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-0004, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Sato
authors.affiliation: Department of Orthopaedic Surgery, Kyorin University, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-0004, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ichimura
mesh_terms: D000367:Age Factors; D000818:Animals; D002574:Cervical Vertebrae; D004195:Disease Models, Animal; D005552:Forelimb / Q000294:innervation / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function; D013116:Spinal Cord; D013119:Spinal Cord Injuries / Q000534:rehabilitation* / Q000628:therapy; D034941:Upper Extremity / Q000503:physiopathology