Evaluation of a novel post-stroke epilepsy model in the rat

Abstract

With the development of treatment and reduction in mortality after stroke, current research focuses more on the disabilities of survivors. Post-stroke epilepsy (PSE) is one of the common complications of stroke. PSE is defined as recurrent epileptic seizures following stroke. Many stroke models have been used to study the mechanisms behind PSE. However, the low success rate of PSE in these models has been a major limitation. To address this problem, we have developed a novel rat model of PSE. In this PSE model, temporal lobe epilepsy (TLE) was induced one week after the creation of photothrombotic stroke. Video monitoring was used to estimate the frequencies of spontaneous recurrent seizures (SRS) 6 to 8 weeks after installation of TLE. Morris water maze (MWM), open field, and three hyperexcitability tests were used to analyse spatial memory, anxiety, and aggressivity, respectively. Our data revealed that the PSE group has an aggravated aggression intensity, impaired anxiety, brain atrophy, mossy fiber sprouting (MFS) when compared to the Lithium-pilocarpine (LIP) epilepsy group. However, there was no significant difference in SRS frequency. In addition, we evaluated the benefits of melatonin as a treatment in this PSE model. Our present results showed that melatonin mitigated impaired spatial memory and reduced impaired anxiety, aggression intensity and brain atrophy when compared to vehicle. Furthermore, melatonin attenuated the abnormal MFS, and decreased serum corticosterone concentration in brain tissues when compared to vehicle. However, melatonin did not significantly reduce SRS frequency.