Detailed spectral profile analysis of electrocorticograms during freezing against penicillin-induced epileptiform discharges in the anesthetized rat

Anticonvulsive effects of edaravone on penicillin-induced focal onset seizure model in the conscious rats

Edaravone is a potent antioxidant and anti-inflammatory agent that is used in the clinic. The aim of the present study was to evaluate the chronic treatment effect of edaravone on penicillin-induced epileptiform activity. Twenty-eight Wistar rats were randomly divided into a total of four groups as penicillin control and edaravone pretreatment groups (1, 10, and 30mg/kg). Firstly, permanent electrodes for electrocorticography (ECoG) recording and canula for penicillin injection were placed as stereotactic under anesthesia. At the end of the recovery period, edaravone pretreatment groups received different doses of edaravone by intraperitoneal injection for 14 days and before 30-min penicillin microinjection. Epileptiform activity was induced by injecting 500 IU penicillin through the intracortical cannula. The effects of edaravone pretreatment on epileptiform activity were evaluated by using both electrophysiological and behavioral parameters. Edaravone pretreatment suppressed epileptiform activity by reducing the mean spike frequency and the behavior scores in ECoG recording. The results of the present study indicated that the use of chronic edaravone had an anticonvulsant effect on penicillin-induced focal onset epileptic activity. Edaravone had an anticonvulsant effect even at low doses.

A Palm-Sized Cryoprobe System With a Built-In Thermocouple and Its Application in an Animal Model of Epilepsy

OBJECTIVE

The purpose of this study is to propose a palm-sized cryoprobe system with a built-in thermocouple (TC) for highly accurate and sensitive temperature measurements, and to verify the effectiveness of the system.

METHODS

Conventional cryoprobe systems based on the boiling effect of a refrigerant have triple coaxial tubes. In the proposed system, the outer and middle coaxial tubes are made of two different metals that are welded only at the probe tip, thereby forming a TC. The thermoelectric properties of the built-in TC and measurement accuracy were investigated in agar in a constant-temperature chamber. The system was also applied in a penicillin G-induced rat brain epilepsy model.

RESULTS

We verified that the built-in TC has appropriate thermoelectric properties and that the system more accurately and sensitively measured transient temperature changes at the probe tip wall compared to conventional systems, showing the cooling performance of the system. In the rat model, epileptiform activities disappeared on freezing, and reliable cell necrosis was achieved at an end temperature of -45.2 ± 1.6 °C.

CONCLUSIONS

The proposed system is suitable for reliable cryosurgery.

SIGNIFICANCE

The system is probably to be valuable for clarifying the relationship between freezing temperature and cell necrosis in vivo.