University of Tasmania

File(s) not publicly available

Development of walking, swimming and neuronal connections after complete spinal cord transection in the neonatal opossum, Monodelphis domestica

journal contribution
posted on 2023-05-16, 11:09 authored by Norman SaundersNorman Saunders, Kitchener, PD, Knott, GW, Nicholls, JG, Potter, A, Tracey WallsTracey Walls
Development of coordinated movements was quantitatively assessed in adult opossums (Monodelphis domestica) with thoracic spinal cords transected by (1) crushing 7-8 d after birth [postnatal days 7-8 (P7-P8)]; at 2-3 years of age, systematic behavioral tests (e.g., climbing, footprint analysis, and swimming) showed only minor differences between control (n = 5) and operated (n = 10) animals; and (2) cutting on P4-P6; at 1 month these opossums exhibited coordinated walking movements but were unable to right themselves from a supine position, unlike controls (n = 6). When tested at 2 or 6 months, they could right themselves and showed remarkable coordination, albeit with more differences from controls than after a crush. No animals with spinal cords that were crushed at P14-18 survived because of cannibalism by the mother. Morphological studies (n = 10) 3 months-3 years after crush at 1 week showed restoration of structural continuity and normal appearance at the lesion site. Animals with cut rather than crushed cords showed continuity but greater morphological deficits. That lesions were complete was demonstrated by examining morphology and nerve impulse conduction immediately after crushing or cutting the spinal cord in controls. After lumbar spinal cord injection of 10 kDa dextran amine, retrogradely labeled cells were found rostral to the lesion in hindbrain and midbrain nuclei. Conduction was restored across the site of the lesion. Thus complete spinal cord transection in neonatal Monodelphis was followed by development of coordinated movements and repair of the spinal cord, a process that included development of functional connections by axons that crossed the lesion.


Publication title

Journal of Neuroscience








Tasmanian School of Medicine


Society for Neuroscience

Place of publication

11 Dupont Circle, Nw, Ste 500, Washington, USA, Dc, 20036

Repository Status

  • Restricted

Socio-economic Objectives

Other health not elsewhere classified

Usage metrics

    University Of Tasmania


    Ref. manager