Objectives: 

In adult humans, the combine treatment with growth hormone (GH) and rehabilitation attenuates many of the pathophysiological events following traumatic brain injury. Here we aimed to explore the effect of GH treatment and rehabilitation in adult rats with severe frontal cortex ablation.

Materials: 

Animals were trained in paw-reaching for food task and the preferred forelimb was recorded. Anaesthetised animals were lesioned by aspiration in the motor cortex contralateral to the preferred forelimb or sham-operated. Rats received subcutaneously injection of GH or vehicle during 5 days, starting either immediately or 6 days post-lesion. Rehabilitation was applied at short and long-term after GH treatment. Behavioral data were analized by ANOVA following Bonferroni post hoc test. After two months post-lesion, immunohistochemical expression of glial fibrillary acidic protein (GFAP), nestin and GH were undertaken in the brain of experimental and sham control animals.

Results: 

Lesion rats GH-treated immediately after cortical lesion showed a significant improve of the motor impairment induced by the motor lesion, and their performance in the paw reaching test were no-different from either GH-or vehicle treated sham controls. However, lesion animals treated with GH after 6 days of lesion did not improve the motor impairment. Lesion animals treated with GH or vehicle showed increased GFAP immunoreactivity and nestin re-expression in the perilesional area. GFAP immunoreactivity in the animals GH or vehicle-treated was similar. In animals treated with GH after 6 days of lesion, nestin re-expression was more intense than in animals that received the GH treatment immediately after lesion or animals treated with vehicle.

Conclusions: 

Our findings show that the GH treatment administered immediately after the cortical lesion induces significant improve of the motor impairment produced by severe frontal cortical ablation.

Acknowledgements: 

Javier Blanco and Noelia González for their excellent technical assistance.