Aims: 

Cortical Spreading Depression (CSD) is a self propagating front of depolarization associated with a depression of the neuronal activity for several minutes and an increase of glucose and O₂ consumption. Previous studies have demonstrated that preconditioning with CSD induces tolerance to a subsequent episode of ischaemia. The mechanism of this tolerance is not clear. The aim of the present work was to evaluate the expression of the uncoupling protein 5 (UCP5) after CSD, that is a candidate neuroprotective factor.

Methods: 

Unilateral CSD was induced for 15 min by application of KCl on the right cortex of 5 groups of rats. The animals were sacrificed at 15 min, 2 h, 4 h, 6 h or 24 h after CSD. The amount of UCP5 in both the CSD-treated and the contralateral cortex was evaluated by Western Blot.

Results: There was a significant increase of UCP5 in the CSD-treated cortex at 24 h; no difference of UCP5 levels between the two cortexes was seen at earlier times.

Conclusion: 

This result suggests that CSD induces the synthesis of UCP5 by 24 h. UCP5 could be involved in the neuroprotection effect of CSD, because the uncoupling proteins reduce the mitochondrial membrane potential, and consequently the production of ROS.