Locomotor activity and spasticity level of the limb in female mice with a spinal cord injury model

Abstract

Spinal cord injuries (SCI) lead to large-scale physical, physiological, psychological and professional losses. Therefore, today, one of the urgent aims of neurophysiology is the study of the consequences of spinal cord injury. The most common type of SCI is a hemisection. For a comprehensive and detailed study of the functional post-traumatic recovery of the spinal cord, various hemisection options are developed. The aim of the study was to analyse the level of locomotor activity and changes in spasticity of the mice ipsilateral hindlimb (IH) after SCI. Materials and methods. The injury of the left-side spinal cord hemisection was modelled at the level of the lower thoracic segments (T10-T11) in female FVB mice. The locomotor activity and spasticity of the IH were determined every week using the Basso-Beattie-Bresnahan (ВВВ), the Basso (B) scales and the Ashworth scale during the first 1-12 weeks of the post-traumatic period. Results. At a later date (the 11th, 12th weeks) compared with the first weeks of the post-traumatic period, there was a marked recovery of the IH function: 4.39±0.61 points (out of 21 possible) on the BBB scale and 2.22±0.31 points (out of 9 possible) on the B scale. However, at all studied time interval after SCI, a consistently high level of hindlimb spasticity in experimental animals was noted, on the 12th week: 3.03±0.39 (out of 4 possible) on the Ashworth scale. Conclusions. After modelling spinal cord injury by hemisection, spontaneous post-traumatic recovery of locomotor activity was observed (since the 2nd week), which had scores corresponding to the early recovery phase. On the other hand, the levels of IH spasticity in mice were quite high throughout the entire study period, although already at the 2nd week there was a slight decrease in this parameter compared to the 1st week of the post-traumatic period.